I previously listed these Tool Post Grinder Spindle Inserts as a set on
Ebay and they did not sell although I had many watchers. I am
re-listing them individually. I am alerting this group because, as you
are probably aware, these inserts are very hard-to-find for sale
independent of the grinder.

Please go to the following Ebay links to see the Dumore inserts:

Ebay Item No.: 7606809797
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ebay Item No.: 7606810929
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ebay Item No.: 7606812039
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ebay Item No.: 7606813161
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ebay Item No.: 7606814190
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ebay Item No.: 7606815347
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ebay Item No.: 7606816411
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ebay Item No.: 7606817416
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ebay Item No.: 7606818193
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

I also have the following items up for auction that may be of interest
to this group:

K.O. Lee 4 Lobe Index Disk for K.O. Lee Model B947 Tap Grinding Fixture
Ebay Item No.: 7606819043
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

Ron Fournier's Metalwork Basic Hand Tools Video VHS (Lowered Price)
Ebay Item No.: 9122305640
Link:
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

If you have any questions about the items, please make them through
Ebay.

According to :
I previously listed these Tool Post Grinder Spindle Inserts as a set on
Ebay and they did not sell although I had many watchers. I am
re-listing them individually. I am alerting this group because, as you
are probably aware, these inserts are very hard-to-find for sale
independent of the grinder.

If only they would fit the series 11 grinders, instead of the
series 57, I would be interested.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
(DoN. Nichols) wrote:

According to :
I previously listed these Tool Post Grinder Spindle Inserts as a set on
Ebay and they did not sell although I had many watchers. I am
re-listing them individually. I am alerting this group because, as you
are probably aware, these inserts are very hard-to-find for sale
independent of the grinder.

If only they would fit the series 11 grinders, instead of the
series 57, I would be interested.

Series 11? I inherited a Series 11 from my maternal grandfather, long
before I had any idea what a toolpost grinder was. I pulled it out of
dusty neglect and ran it, but the spindle bearings don't feel right, and
heat up if the unit is run. The motor is in perfect condition.

Do you have the manual? I'd like to take the spindle apart and see if I
can fix it. If spare parts are available.

Joe Gwinn

Joseph Gwinn wrote:
In article ,

Series 11? I inherited a Series 11 from my maternal grandfather, long
before I had any idea what a toolpost grinder was. I pulled it out of
dusty neglect and ran it, but the spindle bearings don't feel right,
and heat up if the unit is run. The motor is in perfect condition.

Do you have the manual? I'd like to take the spindle apart and see
if I can fix it. If spare parts are available.

Joe Gwinn

Sounds like it just needs proper lubrication.
Could be that the oil in the spindle has hardened over time. Try fresh
spindle oil. Disassenbly is fraught with trouble if you don't know exactly
what you are doing.

Ken.
--
Volunteer your idle computer time for cancer research
http//www.grid.org/download/gold/download.htm
Return address courtesy of Spammotel http://www.spammotel.com/

In article ,
"Ken Davey" wrote:

Joseph Gwinn wrote:
In article ,

Series 11? I inherited a Series 11 from my maternal grandfather, long
before I had any idea what a toolpost grinder was. I pulled it out of
dusty neglect and ran it, but the spindle bearings don't feel right,
and heat up if the unit is run. The motor is in perfect condition.

Do you have the manual? I'd like to take the spindle apart and see
if I can fix it. If spare parts are available.

Joe Gwinn

Sounds like it just needs proper lubrication.
Could be that the oil in the spindle has hardened over time. Try fresh
spindle oil. Disassenbly is fraught with trouble if you don't know exactly
what you are doing.

I did oil it to the gills, to no effect. When I turn it by hand, it
feels like gravel in the bearings, and as it ran it got hotter, and it
tightened noticeably. I stopped it before it locked up. I bet the
bearings are toast, so I have little to lose.

Joe

Joseph Gwinn wrote:
In article ,
"Ken Davey" wrote:

Joseph Gwinn wrote:
In article ,

Series 11? I inherited a Series 11 from my maternal grandfather,
long before I had any idea what a toolpost grinder was. I pulled
it out of dusty neglect and ran it, but the spindle bearings don't
feel right, and heat up if the unit is run. The motor is in
perfect condition.

Do you have the manual? I'd like to take the spindle apart and see
if I can fix it. If spare parts are available.

Joe Gwinn

Sounds like it just needs proper lubrication.
Could be that the oil in the spindle has hardened over time. Try
fresh spindle oil. Disassenbly is fraught with trouble if you don't
know exactly what you are doing.

I did oil it to the gills, to no effect. When I turn it by hand, it
feels like gravel in the bearings, and as it ran it got hotter, and it
tightened noticeably. I stopped it before it locked up. I bet the
bearings are toast, so I have little to lose.

Joe
True.
Suggest you cantact Dumore Corp. for advice and prices of new bearings. They
are responsive.
My contact is MNelson at dumorecorp.com

Ken.
--
Volunteer your idle computer time for cancer research
http//www.grid.org/download/gold/download.htm
Return address courtesy of Spammotel http://www.spammotel.com/

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

If only they would fit the series 11 grinders, instead of the
series 57, I would be interested.

Series 11? I inherited a Series 11 from my maternal grandfather, long
before I had any idea what a toolpost grinder was. I pulled it out of
dusty neglect and ran it, but the spindle bearings don't feel right, and
heat up if the unit is run. The motor is in perfect condition.

Interesting -- one of the bearings in my *motor* feels lumpy,
but the spindle bearings are in great shape.

Do you have the manual?

Don't I wish! I presume that you don't, either. If I could get
it, I would scan it and make it available for download, as I have done
with my manual for the Dumore drill sharpening setup, which handles from
1/4" down to #70 drill bits.

I'd like to take the spindle apart and see if I
can fix it. If spare parts are available.

Not from Dumore, at least. Same for the manuals.

I don't know whether it is obvious on yours, (it was rather
hidden on mine), but there are a pair of holes in the faces of the
bearing caps for a two-pin spanner to use to unscrew the caps.

Do you have the wrench for holding the pulleys still while you
undo the nuts securing them? I'm going to have to make one. I just
made a wheel guard for mine for the larger wheels (if I can ever get the
nut off the smaller pulley on the spindle to swap them for slower speeds
for the larger wheels).

I also need to make the adaptors for mounted stones for inside
grinding. I *think* that the thread on the business end of the spindle
is 1/4-32, and have just ordered some taps and a die for making things
to fit -- and for cleaning up the threads on my spindle.

There appear to be three lube points for the spindle -- one with
the flip-top lid near the center, and two with felt plugs under hollow
screws near the ends -- probably for small needle roller bearing cages.

The bearings in the motor are sealed, and I think that I'll need
to replace one -- the one at the pulley end.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

If only they would fit the series 11 grinders, instead of the
series 57, I would be interested.

Series 11? I inherited a Series 11 from my maternal grandfather, long
before I had any idea what a toolpost grinder was. I pulled it out of
dusty neglect and ran it, but the spindle bearings don't feel right, and
heat up if the unit is run. The motor is in perfect condition.

Interesting -- one of the bearings in my *motor* feels lumpy,
but the spindle bearings are in great shape.

I bet replacing a motor bearing is easier than a spindle bearing.


Do you have the manual?

Don't I wish! I presume that you don't, either. If I could get
it, I would scan it and make it available for download, as I have done
with my manual for the Dumore drill sharpening setup, which handles from
1/4" down to #70 drill bits.

No manual here. Anybody?


I'd like to take the spindle apart and see if I
can fix it. If spare parts are available.

Not from Dumore, at least. Same for the manuals.

I'm hoping that they used standard bearings.


I don't know whether it is obvious on yours, (it was rather
hidden on mine), but there are a pair of holes in the faces of the
bearing caps for a two-pin spanner to use to unscrew the caps.

The spanner holes are quite obvious on mine. I'll have to make a
spanner to fit.

Are the screw threads normal (right-handed) or reverse (left-handed)?


Do you have the wrench for holding the pulleys still while you
undo the nuts securing them? I'm going to have to make one. I just
made a wheel guard for mine for the larger wheels (if I can ever get the
nut off the smaller pulley on the spindle to swap them for slower speeds
for the larger wheels).

I don't think so; I'll have to look again. The belts are flat and the
pulleys are smooth and crowned, and a steel-jawed wrench would chew the
pulleys up I would think. Unless there are holes in the pulley disks to
admit the pins of a spanner.

I bet people just grabbed the bigger pulleys by hand, or used a strap
wrench on the crown.

Are the pulley nuts right-hand, or left-hand?


I also need to make the adaptors for mounted stones for inside
grinding. I *think* that the thread on the business end of the spindle
is 1/4-32, and have just ordered some taps and a die for making things
to fit -- and for cleaning up the threads on my spindle.

There appear to be three lube points for the spindle -- one with
the flip-top lid near the center, and two with felt plugs under hollow
screws near the ends -- probably for small needle roller bearing cages.

I found three as well, and filled them all with oil.


The bearings in the motor are sealed, and I think that I'll need
to replace one -- the one at the pulley end.

On mine, the bearings are not equally toasted, but I'll replace both if
I can.


Good Luck,
DoN.

I wish luck were not required, but Thanks.

Joe Gwinn

In article ,
"Ken Davey" wrote:

Joseph Gwinn wrote:
In article ,
"Ken Davey" wrote:

Joseph Gwinn wrote:
In article ,

Series 11? I inherited a Series 11 from my maternal grandfather,
long before I had any idea what a toolpost grinder was. I pulled
it out of dusty neglect and ran it, but the spindle bearings don't
feel right, and heat up if the unit is run. The motor is in
perfect condition.

Do you have the manual? I'd like to take the spindle apart and see
if I can fix it. If spare parts are available.

Joe Gwinn

Sounds like it just needs proper lubrication.
Could be that the oil in the spindle has hardened over time. Try
fresh spindle oil. Disassenbly is fraught with trouble if you don't
know exactly what you are doing.

I did oil it to the gills, to no effect. When I turn it by hand, it
feels like gravel in the bearings, and as it ran it got hotter, and it
tightened noticeably. I stopped it before it locked up. I bet the
bearings are toast, so I have little to lose.

Joe
True.
Suggest you contact Dumore Corp. for advice and prices of new bearings. They
are responsive.
My contact is MNelson at dumorecorp.com

I'll try this. Thanks.

Joe Gwinn

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :

Series 11? I inherited a Series 11 from my maternal grandfather, long
before I had any idea what a toolpost grinder was. I pulled it out of
dusty neglect and ran it, but the spindle bearings don't feel right, and
heat up if the unit is run. The motor is in perfect condition.

Interesting -- one of the bearings in my *motor* feels lumpy,
but the spindle bearings are in great shape.

I bet replacing a motor bearing is easier than a spindle bearing.

Yep! As long as I can find the proper replacement. These are
wider than I would have expected for the diameter. I'll have to dig out
the number from one and see what I can find to match.

Do you have the manual?

Don't I wish! I presume that you don't, either. If I could get
it, I would scan it and make it available for download, as I have done
with my manual for the Dumore drill sharpening setup, which handles from
1/4" down to #70 drill bits.

No manual here. Anybody?

Please? :-)

I'd like to take the spindle apart and see if I
can fix it. If spare parts are available.

Not from Dumore, at least. Same for the manuals.

I'm hoping that they used standard bearings.

Perhaps -- but no bets there. Especially in the spindle.

I don't know whether it is obvious on yours, (it was rather
hidden on mine), but there are a pair of holes in the faces of the
bearing caps for a two-pin spanner to use to unscrew the caps.

The spanner holes are quite obvious on mine. I'll have to make a
spanner to fit.

They were plugged with goop from the polishing wheel which was
packed on it, so not very visible until I cleaned them out.

Are the screw threads normal (right-handed) or reverse (left-handed)?

I don't know. I never have felt the need to pull those caps
off, since my spindle runs smoothly at present.

Do you have the wrench for holding the pulleys still while you
undo the nuts securing them? I'm going to have to make one. I just
made a wheel guard for mine for the larger wheels (if I can ever get the
nut off the smaller pulley on the spindle to swap them for slower speeds
for the larger wheels).

I don't think so; I'll have to look again. The belts are flat and the
pulleys are smooth and crowned, and a steel-jawed wrench would chew the
pulleys up I would think. Unless there are holes in the pulley disks to
admit the pins of a spanner.

I expect the wrench to be something like the one for zeroing a
micrometer -- a quarter circle or so, with a spur to go into the slot in
the hub which engages the flat on the spindle.

I bet people just grabbed the bigger pulleys by hand, or used a strap
wrench on the crown.

The larger pulley came off nicely with just that -- a hand grip.

The smaller one (on the spindle) is too tight.

I think that I'll have to make a collet style clamp for the OD
to hold it unless I can make a working hook wrench as above.

Are the pulley nuts right-hand, or left-hand?

The one on the motor is for sure right-handed. The spindle
*look* right-handed from what I can see of the threads, but until I get
it off, I can't be sure. If you can get the nut off your spindle end
pulley, you could tell *me* which hand it is. (Which side has your
smaller pulley -- the spindle or the motor?)

I also need to make the adaptors for mounted stones for inside
grinding. I *think* that the thread on the business end of the spindle
is 1/4-32, and have just ordered some taps and a die for making things
to fit -- and for cleaning up the threads on my spindle.

There appear to be three lube points for the spindle -- one with
the flip-top lid near the center, and two with felt plugs under hollow
screws near the ends -- probably for small needle roller bearing cages.

I found three as well, and filled them all with oil.

Good -- a light spindle oil, I hope.

The bearings in the motor are sealed, and I think that I'll need
to replace one -- the one at the pulley end.

On mine, the bearings are not equally toasted, but I'll replace both if
I can.

The one on the free end of the motor is in very good condition,
absolutely free motion. But, I'll probably at lest buy two bearings so
I have the option of replacing it at need.


Good Luck,
DoN.

I wish luck were not required, but Thanks.

And the same to you.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :

Series 11? I inherited a Series 11 from my maternal grandfather, long
before I had any idea what a toolpost grinder was. I pulled it out of
dusty neglect and ran it, but the spindle bearings don't feel right,
and
heat up if the unit is run. The motor is in perfect condition.

Interesting -- one of the bearings in my *motor* feels lumpy,
but the spindle bearings are in great shape.

I bet replacing a motor bearing is easier than a spindle bearing.

Yep! As long as I can find the proper replacement. These are
wider than I would have expected for the diameter. I'll have to dig out
the number from one and see what I can find to match.

I doubt that Dumore makes their own bearings. Actually, theyt may still
use the same bearings, or will know where they got them.


I'd like to take the spindle apart and see if I
can fix it. If spare parts are available.

Not from Dumore, at least. Same for the manuals.

I'm hoping that they used standard bearings.

Perhaps -- but no bets there. Especially in the spindle.

If it's a ball/needle bearing, they probably buy them from one of the
usual suspects. Ball/needle bearing manufacture is very specialized.


Are the screw threads normal (right-handed) or reverse (left-handed)?

I don't know. I never have felt the need to pull those caps
off, since my spindle runs smoothly at present.

OK. I'll have to fiddle a bit, will assume right-hand at first.

I bet that this has not changed, so these spindle caps will work the
same way on current models.


Do you have the wrench for holding the pulleys still while you
undo the nuts securing them? I'm going to have to make one. I just
made a wheel guard for mine for the larger wheels (if I can ever get the
nut off the smaller pulley on the spindle to swap them for slower speeds
for the larger wheels).

I don't think so; I'll have to look again. The belts are flat and the
pulleys are smooth and crowned, and a steel-jawed wrench would chew the
pulleys up I would think. Unless there are holes in the pulley disks to
admit the pins of a spanner.

I expect the wrench to be something like the one for zeroing a
micrometer -- a quarter circle or so, with a spur to go into the slot in
the hub which engages the flat on the spindle.

I just looked at the unit. I think it would be hard to keep a
quarter-circle spanner on that. I would guess that a piece of thick
sheet metal with two teeth coming in 180 degrees apart would work better.


I bet people just grabbed the bigger pulleys by hand, or used a strap
wrench on the crown.

The larger pulley came off nicely with just that -- a hand grip.

The smaller one (on the spindle) is too tight.

I was able to get both pulleys off without difficulty, although the
smaller didn't want to slide on the shaft after the nut was removed.
What worked was a set of Jacobs JT1 wedges applied by hand. This
started the pulley sliding, breaking the gummed oil bond loose. Solvent
would also help.


I think that I'll have to make a collet style clamp for the OD
to hold it unless I can make a working hook wrench as above.

Or, bore a hole the same size as the pulley in a piece of hardwood, saw
into two halves, and use the pieces in a vice to firmly grip the pulley,
and have at the nut with a socket wrench.

I've used this trick to disassemble an old B&S micrometer, using two
oaken clamps on the knurls.


Are the pulley nuts right-hand, or left-hand?

The one on the motor is for sure right-handed. The spindle
*looks* right-handed from what I can see of the threads, but until I get
it off, I can't be sure. If you can get the nut off your spindle end
pulley, you could tell *me* which hand it is. (Which side has your
smaller pulley -- the spindle or the motor?)

It turns out that they are both right hand.

My unit is set up the same way, with big pulley on motor and small
pulley on spindle. If the motor turns at 5000 RPM, the spindle will
turn (2.165/0.906)= 2.39 times faster, or 11,948 rpm.


I also need to make the adaptors for mounted stones for inside
grinding. I *think* that the thread on the business end of the spindle
is 1/4-32, and have just ordered some taps and a die for making things
to fit -- and for cleaning up the threads on my spindle.

There appear to be three lube points for the spindle -- one with
the flip-top lid near the center, and two with felt plugs under hollow
screws near the ends -- probably for small needle roller bearing cages.

I found three as well, and filled them all with oil.

Good -- a light spindle oil, I hope.

Well, ordinary motor oil. 10W-30? What grade is light spindle oil?


The bearings in the motor are sealed, and I think that I'll need
to replace one -- the one at the pulley end.

On mine, the bearings are not equally toasted, but I'll replace both if
I can.

The one on the free end of the motor is in very good condition,
absolutely free motion. But, I'll probably [buy] at least buy two bearings so
I have the option of replacing it at need.

Good idea.

Joe Gwinn


Good Luck,
DoN.

I wish luck were not required, but Thanks.

And the same to you.

Enjoy,
DoN.

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

Yep! As long as I can find the proper replacement. These are
wider than I would have expected for the diameter. I'll have to dig out
the number from one and see what I can find to match.

I doubt that Dumore makes their own bearings. Actually, theyt may still
use the same bearings, or will know where they got them.

Yes -- but some styles of bearings are no longer made.
Certainly this is true for the bearings in the spindle of my Sanford
surface grinder. The manual I got from them (perhaps the last thing
that *anyone* got from them before they apparently closed shop) was
fairly old, and it was already talking about the spindle bearings not
being made in the US any more, and they had to get them from France, or
Japan at that time. Who knows whether those are still made at all? And
who knows whether something similar has befallen the older Dumore lines?

[ ... ]

I'm hoping that they used standard bearings.

Perhaps -- but no bets there. Especially in the spindle.

If it's a ball/needle bearing, they probably buy them from one of the
usual suspects. Ball/needle bearing manufacture is very specialized.

Yes -- but they still might not be still in production. The
later ones appear to have a larger diameter spindle, with extensions
screwing in and locking with a taper.

Are the screw threads normal (right-handed) or reverse (left-handed)?

I don't know. I never have felt the need to pull those caps
off, since my spindle runs smoothly at present.

OK. I'll have to fiddle a bit, will assume right-hand at first.

I bet that this has not changed, so these spindle caps will work the
same way on current models.

I hope so.

Do you have the wrench for holding the pulleys still while you
undo the nuts securing them? I'm going to have to make one. I just
made a wheel guard for mine for the larger wheels (if I can ever get the
nut off the smaller pulley on the spindle to swap them for slower speeds
for the larger wheels).

I don't think so; I'll have to look again. The belts are flat and the
pulleys are smooth and crowned, and a steel-jawed wrench would chew the
pulleys up I would think. Unless there are holes in the pulley disks to
admit the pins of a spanner.

I expect the wrench to be something like the one for zeroing a
micrometer -- a quarter circle or so, with a spur to go into the slot in
the hub which engages the flat on the spindle.

I just looked at the unit. I think it would be hard to keep a
quarter-circle spanner on that. I would guess that a piece of thick
sheet metal with two teeth coming in 180 degrees apart would work better.

Perhaps -- except that I'm not sure that it could be fitted into
the slots while the pulley is in place. Perhaps so.

I bet people just grabbed the bigger pulleys by hand, or used a strap
wrench on the crown.

The larger pulley came off nicely with just that -- a hand grip.

The smaller one (on the spindle) is too tight.

I was able to get both pulleys off without difficulty, although the
smaller didn't want to slide on the shaft after the nut was removed.
What worked was a set of Jacobs JT1 wedges applied by hand. This
started the pulley sliding, breaking the gummed oil bond loose. Solvent
would also help.

Yes -- there was some interesting gummed oil under the pulley on
the spindle when I finally got it off.


I think that I'll have to make a collet style clamp for the OD
to hold it unless I can make a working hook wrench as above.

Or, bore a hole the same size as the pulley in a piece of hardwood, saw
into two halves, and use the pieces in a vice to firmly grip the pulley,
and have at the nut with a socket wrench.

I just got through making the collet style clamp wrench.
picture a ring covering perhaps 300 degrees of the diameter, with
handles coming off where they join. Squeeze on the handles and the ring
tightens down on the pulley. I didn't bother making it pretty (yet) and
it is pretty stiff, but it worked, once I put the handles in a vise.
And at this point, I discovered that the pulley end of the spindle is
also right-hand threads.

I'll pretty it up later, and keep it in the box with the
toolpost grinder, along with the other accessories I have made. Out of
curiosity -- what color is the box for yours? Mine is a sort of light
blue -- almost hammertone, but I have seen other boxes which were black
crinkle finish, or Olive Drab.

I also need to make a holder for a truing diamond to hold in the
lathe chuck -- or in collets. But the machine is almost ready to use.
Then the question is how long can I resist using it, since I don't like
to expose the lathe to the grinding grit if I don't have to.

I've used this trick to disassemble an old B&S micrometer, using two
oaken clamps on the knurls.

If I had knurls to grip I would have gone with hardwood too. As
it was, I went with aluminum, with the lathe vibrating nicely with the
one jaw so far off center (and workpiece as well) at 550 RPM.
(Actually, slower was resonance -- perhaps around 300 RPM, and 550 RPM
was not bad. :-)

Are the pulley nuts right-hand, or left-hand?

The one on the motor is for sure right-handed. The spindle
*looks* right-handed from what I can see of the threads, but until I get
it off, I can't be sure. If you can get the nut off your spindle end
pulley, you could tell *me* which hand it is. (Which side has your
smaller pulley -- the spindle or the motor?)

It turns out that they are both right hand.

As I discovered.

My unit is set up the same way, with big pulley on motor and small
pulley on spindle. If the motor turns at 5000 RPM, the spindle will
turn (2.165/0.906)= 2.39 times faster, or 11,948 rpm.

*Way* too fast for the larger stones. But reasonable for the
mounted stones for inside grinding. (And I don't have the holders for
those -- yet. I've made the wheel shatter guard, and several hub
adaptors for different stones which I have, including a set still left
from the old Unimat SL-1000.

The next task is to make some holders for the mounted stones --
1/8" shank -- and perhaps smaller as well. There were some of each type
in the kit.


I also need to make the adaptors for mounted stones for inside
grinding. I *think* that the thread on the business end of the spindle
is 1/4-32, and have just ordered some taps and a die for making things
to fit -- and for cleaning up the threads on my spindle.

There appear to be three lube points for the spindle -- one with
the flip-top lid near the center, and two with felt plugs under hollow
screws near the ends -- probably for small needle roller bearing cages.

I found three as well, and filled them all with oil.

Good -- a light spindle oil, I hope.

Well, ordinary motor oil. 10W-30? What grade is light spindle oil?

10W-30 doesn't sound right. Too thick for the kind of speed
which the large pulley on motor gives. I got a light spindle oil from
MSC for the surface grinder spindle, and that will work on the Dumore
toolpost grinder as well. Though I have been known to use the Starrett
"Tool and Instrument Oil", which is similarly light.

I think that the spindle oil was labeled as an ISO-27, but I may
be misremembering. Dive into your MSC catalog, and find the lightest
which you can find.

And I hope that your motor oil was not a detergent oil. If so,
you want to wash it out before running it again. Detergent oils should
only be used where there is recirculation through a filter.

The bearings in the motor are sealed, and I think that I'll need
to replace one -- the one at the pulley end.

On mine, the bearings are not equally toasted, but I'll replace both if
I can.

The one on the free end of the motor is in very good condition,
absolutely free motion. But, I'll probably [buy] at least buy two bearings so
I have the option of replacing it at need.

Good idea.

I originally freed up the motor bearing somewhat by hitting it
with a heat gun. Then I was able to run it several times, and it felt
better each time. It now feels pretty good. But I still want new
pulleys.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

Yep! As long as I can find the proper replacement. These are
wider than I would have expected for the diameter. I'll have to dig out
the number from one and see what I can find to match.

I doubt that Dumore makes their own bearings. Actually, theyt may still
use the same bearings, or will know where they got them.

Yes -- but some styles of bearings are no longer made.
Certainly this is true for the bearings in the spindle of my Sanford
surface grinder. The manual I got from them (perhaps the last thing
that *anyone* got from them before they apparently closed shop) was
fairly old, and it was already talking about the spindle bearings not
being made in the US any more, and they had to get them from France, or
Japan at that time. Who knows whether those are still made at all? And
who knows whether something similar has befallen the older Dumore lines?

Right. Well, we shall soon enough see.


I'm hoping that they used standard bearings.

Perhaps -- but no bets there. Especially in the spindle.

If it's a ball/needle bearing, they probably buy them from one of the
usual suspects. Ball/needle bearing manufacture is very specialized.

Yes -- but they still might not be still in production. The
later ones appear to have a larger diameter spindle, with extensions
screwing in and locking with a taper.

OK. I have not had mine apart yet. Are you talking about the motor
bearings?


Do you have the wrench for holding the pulleys still while you
undo the nuts securing them? I'm going to have to make one. I just
made a wheel guard for mine for the larger wheels (if I can ever get
the nut off the smaller pulley on the spindle to swap them for slower
speeds for the larger wheels).

I don't think so; I'll have to look again. The belts are flat and the
pulleys are smooth and crowned, and a steel-jawed wrench would chew the
pulleys up I would think. Unless there are holes in the pulley disks
to admit the pins of a spanner.

I expect the wrench to be something like the one for zeroing a
micrometer -- a quarter circle or so, with a spur to go into the slot in
the hub which engages the flat on the spindle.

I just looked at the unit. I think it would be hard to keep a
quarter-circle spanner on that. I would guess that a piece of thick
sheet metal with two teeth coming in 180 degrees apart would work better.

Perhaps -- except that I'm not sure that it could be fitted into
the slots while the pulley is in place. Perhaps so.

On mine it can, so long as the sheet metal isn't too thick. The gap is
0.200" or more, and the tool needn't be more than 0.100" thick. It
could be made from a piece of oil-hardening steel.


I bet people just grabbed the bigger pulleys by hand, or used a strap
wrench on the crown.

The larger pulley came off nicely with just that -- a hand grip.

The smaller one (on the spindle) is too tight.

I was able to get both pulleys off without difficulty, although the
smaller didn't want to slide on the shaft after the nut was removed.
What worked was a set of Jacobs JT1 wedges applied by hand. This
started the pulley sliding, breaking the gummed oil bond loose. Solvent
would also help.

Yes -- there was some interesting gummed oil under the pulley on
the spindle when I finally got it off.

My grandfather must have bought the unit in the late 1940s.


I think that I'll have to make a collet style clamp for the OD
to hold it unless I can make a working hook wrench as above.

Or, bore a hole the same size as the pulley in a piece of hardwood, saw
into two halves, and use the pieces in a vice to firmly grip the pulley,
and have at the nut with a socket wrench.

I just got through making the collet style clamp wrench.
picture a ring covering perhaps 300 degrees of the diameter, with
handles coming off where they join. Squeeze on the handles and the ring
tightens down on the pulley. I didn't bother making it pretty (yet) and
it is pretty stiff, but it worked, once I put the handles in a vise.
And at this point, I discovered that the pulley end of the spindle is
also right-hand threads.

A ring wrench, writ large. I thought of doing this, but in wood, which
has very high friction against steel. But the nuts yielded without the
need for added persuasion.


I'll pretty it up later, and keep it in the box with the
toolpost grinder, along with the other accessories I have made. Out of
curiosity -- what color is the box for yours? Mine is a sort of light
blue -- almost hammertone, but I have seen other boxes which were black
crinkle finish, or Olive Drab.

Mine is olive drab, all steel, 12.5" wide by 7.5" deep by 7" high, with
drop front.

A random collection of stones et al are included, but no pulleys aside
from those on the grinder.


I also need to make a holder for a truing diamond to hold in the
lathe chuck -- or in collets. But the machine is almost ready to use.
Then the question is how long can I resist using it, since I don't like
to expose the lathe to the grinding grit if I don't have to.

I've used this trick to disassemble an old B&S micrometer, using two
oaken clamps on the knurls.

If I had knurls to grip I would have gone with hardwood too. As
it was, I went with aluminum, with the lathe vibrating nicely with the
one jaw so far off center (and workpiece as well) at 550 RPM.
(Actually, slower was resonance -- perhaps around 300 RPM, and 550 RPM
was not bad. :-)

What is the swing on this lathe?


Are the pulley nuts right-hand, or left-hand?

The one on the motor is for sure right-handed. The spindle
*looks* right-handed from what I can see of the threads, but until I get
it off, I can't be sure. If you can get the nut off your spindle end
pulley, you could tell *me* which hand it is. (Which side has your
smaller pulley -- the spindle or the motor?)

It turns out that they are both right hand.

As I discovered.

My unit is set up the same way, with big pulley on motor and small
pulley on spindle. If the motor turns at 5000 RPM, the spindle will
turn (2.165/0.906)= 2.39 times faster, or 11,948 rpm.

*Way* too fast for the larger stones. But reasonable for the
mounted stones for inside grinding. (And I don't have the holders for
those -- yet. I've made the wheel shatter guard, and several hub
adaptors for different stones which I have, including a set still left
from the old Unimat SL-1000.

I think that's what Grandfather was using it for. I remember him
showing me a test piece consisting of a 0.5000" steel plunger fitted
into a socket with only 0.0001" clearance, such that it was almost
airtight, and the plunger would bounce up and down on the trapped air
acting as a spring. I don't recall why he made this, aside from it
being for some invention he was working on. His big thing was fuel
injection systems for automobiles, and there was a Corvette model that
offered his system as a factory option. I don't recall that the option
sold all that well.


The next task is to make some holders for the mounted stones --
1/8" shank -- and perhaps smaller as well. There were some of each type
in the kit.


I also need to make the adaptors for mounted stones for inside
grinding. I *think* that the thread on the business end of the
spindle
is 1/4-32, and have just ordered some taps and a die for making
things
to fit -- and for cleaning up the threads on my spindle.

There appear to be three lube points for the spindle -- one with
the flip-top lid near the center, and two with felt plugs under
hollow
screws near the ends -- probably for small needle roller bearing
cages.

I found three as well, and filled them all with oil.

Good -- a light spindle oil, I hope.

Well, ordinary motor oil. 10W-30? What grade is light spindle oil?

10W-30 doesn't sound right. Too thick for the kind of speed
which the large pulley on motor gives. I got a light spindle oil from
MSC for the surface grinder spindle, and that will work on the Dumore
toolpost grinder as well. Though I have been known to use the Starrett
"Tool and Instrument Oil", which is similarly light.

I think that the spindle oil was labeled as an ISO-27, but I may
be misremembering. Dive into your MSC catalog, and find the lightest
which you can find.

And I hope that your motor oil was not a detergent oil. If so,
you want to wash it out before running it again. Detergent oils should
only be used where there is recirculation through a filter.

Hmm. I'll get better oil. Too-heavy oil would cause heating, but I'm
still suspicious of the spindle bearings. It may be simply some rust
that will vanish into the oil with use, but I think I will still take
the spindle apart.


The bearings in the motor are sealed, and I think that I'll need
to replace one -- the one at the pulley end.

On mine, the bearings are not equally toasted, but I'll replace both if
I can.

The one on the free end of the motor is in very good condition,
absolutely free motion. But, I'll probably [buy] at least buy two
bearings so
I have the option of replacing it at need.

Good idea.

I originally freed up the motor bearing somewhat by hitting it
with a heat gun. Then I was able to run it several times, and it felt
better each time. It now feels pretty good. But I still want new
pulleys.

What's wrong with the pulleys? Flat belts are pretty tolerant of
smoothed-out dings.


Joe Gwinn

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

I doubt that Dumore makes their own bearings. Actually, theyt may still
use the same bearings, or will know where they got them.

Yes -- but some styles of bearings are no longer made.
Certainly this is true for the bearings in the spindle of my Sanford
surface grinder. The manual I got from them (perhaps the last thing
that *anyone* got from them before they apparently closed shop) was
fairly old, and it was already talking about the spindle bearings not
being made in the US any more, and they had to get them from France, or
Japan at that time. Who knows whether those are still made at all? And
who knows whether something similar has befallen the older Dumore lines?

Right. Well, we shall soon enough see.

I hope that you luck out there. I suspect that the needle
roller bearings in the spindle run directly on a hardened and ground
surface of the spindle. (You need a toolpost grinder to make the
spindle to fix your toolpost grinder. :-)


I'm hoping that they used standard bearings.

Perhaps -- but no bets there. Especially in the spindle.

If it's a ball/needle bearing, they probably buy them from one of the
usual suspects. Ball/needle bearing manufacture is very specialized.

Yes -- but they still might not be still in production. The
later ones appear to have a larger diameter spindle, with extensions
screwing in and locking with a taper.

OK. I have not had mine apart yet. Are you talking about the motor
bearings?

There, I am talking about the spindle bearings. On mine, there
is a projecting section of perhaps 1/2" (not measured), with a following
unthreaded section of 1/4", and finally a thread which appears to be
1/4-32 thread (though I kept getting not quite right measurements which
suggested that it was somewhere between 32 TPI and 30 TPI. Perhaps it
was a 1/4x8mm thread, which would work out to be 31.75 TPI. Well ... it
is now 32 TPI for sure, thanks to a die. :-) Anyway, I have made
centering hubs for various sizes of grinding wheels, but still need to
make the extension spindles to hold the mounted stones -- collet style,
probably with each size a separate extension spindle. These need to be
bored to the right diameter to slide on and screw onto the current
spindle thread. I may look for a closer nose -- or try my hand at
making one to fit.

Anyway -- the spindle adaptors shown in the eBay auction which
started this thread have a male thread with a taper, which apparently
threads into a somewhat larger hollow spindle. Whether the change in
design was forced by the original bearings becoming unavailable, or was
a voluntary change -- which *may* have taken the demand for the bearings
low enough so they are no longer made. Both are possible. Of course,
they are for a different model -- and probably a much later model than
ours.

[ ... ]

I expect the wrench to be something like the one for zeroing a
micrometer -- a quarter circle or so, with a spur to go into the slot in
the hub which engages the flat on the spindle.

I just looked at the unit. I think it would be hard to keep a
quarter-circle spanner on that. I would guess that a piece of thick
sheet metal with two teeth coming in 180 degrees apart would work better.

Perhaps -- except that I'm not sure that it could be fitted into
the slots while the pulley is in place. Perhaps so.

On mine it can, so long as the sheet metal isn't too thick. The gap is
0.200" or more, and the tool needn't be more than 0.100" thick. It
could be made from a piece of oil-hardening steel.

O.K. That is exactly what I was expecting to make it from.
Though with the ring spanner, I probably won't need to make one right
away. :-)

[ ... ]

Yes -- there was some interesting gummed oil under the pulley on
the spindle when I finally got it off.

My grandfather must have bought the unit in the late 1940s.

O.K. I have no real idea when mine was made.

[ ... ]

I just got through making the collet style clamp wrench.
picture a ring covering perhaps 300 degrees of the diameter, with
handles coming off where they join. Squeeze on the handles and the ring
tightens down on the pulley. I didn't bother making it pretty (yet) and
it is pretty stiff, but it worked, once I put the handles in a vise.
And at this point, I discovered that the pulley end of the spindle is
also right-hand threads.

A ring wrench, writ large. I thought of doing this, but in wood, which
has very high friction against steel. But the nuts yielded without the
need for added persuasion.

While I don't have good woods for the task -- just whatever is
used to make cheap 2x4s these days -- a bit too soft, I think. I did
have to go to a vise because the small pulley was slipping inside with
just a hand grip -- though I have not reduced the size of the OD of the
ring enough yet.

But -- with the vise, it worked.

I'll pretty it up later, and keep it in the box with the
toolpost grinder, along with the other accessories I have made. Out of
curiosity -- what color is the box for yours? Mine is a sort of light
blue -- almost hammertone, but I have seen other boxes which were black
crinkle finish, or Olive Drab.

Mine is olive drab, all steel, 12.5" wide by 7.5" deep by 7" high, with
drop front.

O.K. No drop front on mine. I have to loosen the bolt through
the compound mount, swing the motor forward against the spring, and
slide the T-slot adaptor out backwards to get it out. I suspect that I
would prefer the drop front case -- but I have what I have.

A random collection of stones et al are included, but no pulleys aside
from those on the grinder.

I think for that series, only those two pulleys are supposed to
be used. The metal label on the motor show only two speeds -- with
large pulley on the motor, and with small pulley on the motor -- no
other choices. (Still better than a toolpost grinder which someone
found on one of the small lathe sites which has only a single speed, and
mounts only for wheel stones with holes, not for ones with shanks.)

I also need to make a holder for a truing diamond to hold in the
lathe chuck -- or in collets. But the machine is almost ready to use.
Then the question is how long can I resist using it, since I don't like
to expose the lathe to the grinding grit if I don't have to.

I've used this trick to disassemble an old B&S micrometer, using two
oaken clamps on the knurls.

If I had knurls to grip I would have gone with hardwood too. As
it was, I went with aluminum, with the lathe vibrating nicely with the
one jaw so far off center (and workpiece as well) at 550 RPM.
(Actually, slower was resonance -- perhaps around 300 RPM, and 550 RPM
was not bad. :-)

What is the swing on this lathe?

12" (x24" between centers). A Clausing 5418 from 1957, if you
care.

[ ... ]

My unit is set up the same way, with big pulley on motor and small
pulley on spindle. If the motor turns at 5000 RPM, the spindle will
turn (2.165/0.906)= 2.39 times faster, or 11,948 rpm.

*Way* too fast for the larger stones. But reasonable for the
mounted stones for inside grinding. (And I don't have the holders for
those -- yet. I've made the wheel shatter guard, and several hub
adaptors for different stones which I have, including a set still left
from the old Unimat SL-1000.

I think that's what Grandfather was using it for. I remember him
showing me a test piece consisting of a 0.5000" steel plunger fitted
into a socket with only 0.0001" clearance, such that it was almost
airtight, and the plunger would bounce up and down on the trapped air
acting as a spring.

Nice work. One trick to get that kind of precision is to set
the compound at 5.7106 degrees (as close as you can get, at least), and
for every 0.001" you crank the compound feed, you move 0.0001" closer to
the axis. (If you care, that decimal degrees comes out to be:

5 degrees, 42 minutes, 38 seconds

Good luck on the typical compound angle scale. :-)

I don't recall why he made this, aside from it
being for some invention he was working on. His big thing was fuel
injection systems for automobiles, and there was a Corvette model that
offered his system as a factory option. I don't recall that the option
sold all that well.

Hmm ... do you remember what range of years this was offered on?
That might give a feel for when it was last used and oiled.

[ ... ]

And I hope that your motor oil was not a detergent oil. If so,
you want to wash it out before running it again. Detergent oils should
only be used where there is recirculation through a filter.

Hmm. I'll get better oil. Too-heavy oil would cause heating, but I'm
still suspicious of the spindle bearings. It may be simply some rust
that will vanish into the oil with use, but I think I will still take
the spindle apart.

Agreed. But be careful -- a clean workspace over a tray, in
case a bunch of needle rollers fall out, or a spring launches parts or
itself. (I remember the MGA shop manual when discussing disassembling
the transmission saying:

"Withdraw the three sliding rods and forks. Note the three
balls and springs released in consequence."

"released" actually means launched hard enough to bruise, if you don't
have several layers of cloth to catch them. And if you are not
sufficiently forewarned, they vanish into the weeds surrounding where I
worked on the car. No -- I didn't lose them, but I did get a bit of a
surprise. These were the detent balls which engaged notches in the rods
which slid the gears inside to engage the synchromesh rings.

[ ... ]

I originally freed up the motor bearing somewhat by hitting it
with a heat gun. Then I was able to run it several times, and it felt
better each time. It now feels pretty good. But I still want new
pulleys.

What's wrong with the pulleys? Flat belts are pretty tolerant of
smoothed-out dings.

I actually meant to type "bearings", not "pulleys". :-)

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

I doubt that Dumore makes their own bearings. Actually, they may
still use the same bearings, or will know where they got them.

Yes -- but some styles of bearings are no longer made.
Certainly this is true for the bearings in the spindle of my Sanford
surface grinder. The manual I got from them (perhaps the last thing
that *anyone* got from them before they apparently closed shop) was
fairly old, and it was already talking about the spindle bearings not
being made in the US any more, and they had to get them from France, or
Japan at that time. Who knows whether those are still made at all? And
who knows whether something similar has befallen the older Dumore lines?

Right. Well, we shall soon enough see.

I hope that you luck out there. I suspect that the needle
roller bearings in the spindle run directly on a hardened and ground
surface of the spindle. (You need a toolpost grinder to make the
spindle to fix your toolpost grinder. :-)

I took the spindle apart without difficulty. The bearings consist of
two ball bearings, one at each end, with a fingered flat disk spring at
one end taking up axial play. The bearing races are very thin, and are
pressed into place on the spindle (one end) and a spindle housing cap
(the other end). It does not look possible to remove the pressed-in
bearings without destroying the bearings (by forcing the balls into the
races), and the races are so thin I have to believe that they are
special-order. I think one replaces the assembly, not the bearing.

The good news is that the bearings are OK, but were pretty dirty.

The bearing pressed onto the spindle doesn't seem fully seated, and so
when the spindle body caps are fully screwed down, the axial takeup
spring is flattened. When the spindle is run at high speed and heats
up, the axial pressure on the bearings grows, increasing drag, causing
more heating, etc. This is what I observed when I first rat it at full
speed.

The current fix is to fully tighten the spindle cap that tends to
unscrew itself, and leave the other spindle cap loose by one turn.

For the record, both spindle bearing caps are right-hand threaded. I
used the tips of a pair of needle-node pliers as a spanner wrench. The
caps turned easily. I did see some faint marks left by a pipe wrench on
the caps. Anyway, disassembly and reassembly were easy.


I'm hoping that they used standard bearings.

Perhaps -- but no bets there. Especially in the spindle.

If it's a ball/needle bearing, they probably buy them from one of the
usual suspects. Ball/needle bearing manufacture is very specialized.

Yes -- but they still might not be still in production. The
later ones appear to have a larger diameter spindle, with extensions
screwing in and locking with a taper.

OK. I have not had mine apart yet. Are you talking about the motor
bearings?

There, I am talking about the spindle bearings. On mine, there
is a projecting section of perhaps 1/2" (not measured), with a following
unthreaded section of 1/4", and finally a thread which appears to be
1/4-32 thread (though I kept getting not quite right measurements which
suggested that it was somewhere between 32 TPI and 30 TPI. Perhaps it
was a 1/4x8mm thread, which would work out to be 31.75 TPI. Well ... it
is now 32 TPI for sure, thanks to a die. :-)

Mine has an unthreaded nose with axial hole and grub screw.


Anyway, I have made
centering hubs for various sizes of grinding wheels, but still need to
make the extension spindles to hold the mounted stones -- collet style,
probably with each size a separate extension spindle. These need to be
bored to the right diameter to slide on and screw onto the current
spindle thread. I may look for a closer nose -- or try my hand at
making one to fit.

Anyway -- the spindle adaptors shown in the eBay auction which
started this thread have a male thread with a taper, which apparently
threads into a somewhat larger hollow spindle. Whether the change in
design was forced by the original bearings becoming unavailable, or was
a voluntary change -- which *may* have taken the demand for the bearings
low enough so they are no longer made. Both are possible. Of course,
they are for a different model -- and probably a much later model than
ours.

From the current Dumore catalog, they had an assortment of spindles, and
the user was expected to change spindles as needed. So, there will be
many kinds of spindle floating around, but they should all fit the
grinder.


I expect the wrench to be something like the one for zeroing a
micrometer -- a quarter circle or so, with a spur to go into the slot
in
the hub which engages the flat on the spindle.

I just looked at the unit. I think it would be hard to keep a
quarter-circle spanner on that. I would guess that a piece of thick
sheet metal with two teeth coming in 180 degrees apart would work
better.

Perhaps -- except that I'm not sure that it could be fitted into
the slots while the pulley is in place. Perhaps so.

On mine it can, so long as the sheet metal isn't too thick. The gap is
0.200" or more, and the tool needn't be more than 0.100" thick. It
could be made from a piece of oil-hardening steel.

O.K. That is exactly what I was expecting to make it from.
Though with the ring spanner, I probably won't need to make one right
away. :-)

I looked closely at the smaller pulley when I had it off. The corners
of the slot where the wrench would go are buggered up, and look like
someone tried to use and ordinary wrench on them.


Yes -- there was some interesting gummed oil under the pulley on
the spindle when I finally got it off.

My grandfather must have bought the unit in the late 1940s.

O.K. I have no real idea when mine was made.

I'm guessing that my Grandfather got this unit used and incomplete, in
the 1950s.


I just got through making the collet style clamp wrench.
picture a ring covering perhaps 300 degrees of the diameter, with
handles coming off where they join. Squeeze on the handles and the ring
tightens down on the pulley. I didn't bother making it pretty (yet) and
it is pretty stiff, but it worked, once I put the handles in a vise.
And at this point, I discovered that the pulley end of the spindle is
also right-hand threads.

A ring wrench, writ large. I thought of doing this, but in wood, which
has very high friction against steel. But the nuts yielded without the
need for added persuasion.

While I don't have good woods for the task -- just whatever is
used to make cheap 2x4s these days -- a bit too soft, I think.

The local Home Despot carries Oak, which is what I used. Oak flooring
cutoffs are often available. Likewise, Maple.


I did
have to go to a vise because the small pulley was slipping inside with
just a hand grip -- though I have not reduced the size of the OD of the
ring enough yet.

But -- with the vise, it worked.

Big vice, big hammer -- tools to live by.


Out of
curiosity -- what color is the box for yours? Mine is a sort of light
blue -- almost hammertone, but I have seen other boxes which were black
crinkle finish, or Olive Drab.

Mine is olive drab, all steel, 12.5" wide by 7.5" deep by 7" high, with
drop front.

O.K. No drop front on mine. I have to loosen the bolt through
the compound mount, swing the motor forward against the spring, and
slide the T-slot adaptor out backwards to get it out. I suspect that I
would prefer the drop front case -- but I have what I have.

Does the box say Dumore? Mine does not have any indication of a maker.


A random collection of stones et al are included, but no pulleys aside
from those on the grinder.

I think for that series, only those two pulleys are supposed to
be used. The metal label on the motor show only two speeds -- with
large pulley on the motor, and with small pulley on the motor -- no
other choices. (Still better than a toolpost grinder which someone
found on one of the small lathe sites which has only a single speed, and
mounts only for wheel stones with holes, not for ones with shanks.)

I wondered about the pulleys, because current grinders from Dumore show
more than two sizes.

What speeds are quoted on your grinder? Mine says nothing.


I also need to make a holder for a truing diamond to hold in the
lathe chuck -- or in collets. But the machine is almost ready to use.
Then the question is how long can I resist using it, since I don't like
to expose the lathe to the grinding grit if I don't have to.

Set it up like surgery, with a sheet of plastic covering everything
except what absolutely must poke through?


I've used this trick to disassemble an old B&S micrometer, using two
oaken clamps on the knurls.

If I had knurls to grip I would have gone with hardwood too. As
it was, I went with aluminum, with the lathe vibrating nicely with the
one jaw so far off center (and workpiece as well) at 550 RPM.
(Actually, slower was resonance -- perhaps around 300 RPM, and 550 RPM
was not bad. :-)

What is the swing on this lathe?

12" (x24" between centers). A Clausing 5418 from 1957, if you
care.

Nothing to be ashamed of here, Clausing. Someday.


My unit is set up the same way, with big pulley on motor and small
pulley on spindle. If the motor turns at 5000 RPM, the spindle will
turn (2.165/0.906)= 2.39 times faster, or 11,948 rpm.

*Way* too fast for the larger stones. But reasonable for the
mounted stones for inside grinding. (And I don't have the holders for
those -- yet. I've made the wheel shatter guard, and several hub
adaptors for different stones which I have, including a set still left
from the old Unimat SL-1000.

I think that's what Grandfather was using it for. I remember him
showing me a test piece consisting of a 0.5000" steel plunger fitted
into a socket with only 0.0001" clearance, such that it was almost
airtight, and the plunger would bounce up and down on the trapped air
acting as a spring.

Nice work. One trick to get that kind of precision is to set
the compound at 5.7106 degrees (as close as you can get, at least), and
for every 0.001" you crank the compound feed, you move 0.0001" closer to
the axis. (If you care, that decimal degrees comes out to be:

5 degrees, 42 minutes, 38 seconds

Good luck on the typical compound angle scale. :-)

It's a nice trick, even if one cannot set this on the angle scale. I
would just set it to something, measure the effect of advancing by a set
amount, and then use a hand calculator to figure out what to do to
achieve a specified effect.


I don't recall why he made this, aside from it
being for some invention he was working on. His big thing was fuel
injection systems for automobiles, and there was a Corvette model that
offered his system as a factory option. I don't recall that the option
sold all that well.

Hmm ... do you remember what range of years this was offered on?
That might give a feel for when it was last used and oiled.

I looked through my file of stuff I got from Grandfather (Carl F. High),
and I find a 29-page report titled "Economic relationship of Engine-Fuel
Research" by one C.L. McCuen of the GM Research Labs, dated 3 May 1951,
that tracks characteristics of cars from 1930 through 1950. It's
basically a plea for greater fuel efficiency. I'll have to read the
report; one assumes that fuel injection was to have a role.

My recollection is that it was the 1957 model year Corvette, but I have
not found any documents.


It turns out that the bread and butter was fuel injection systems for
general aviation engines.

I have an ad from the Ex-Cell-O Corporation in Detroit (where
Grandfather lived) for their "Gasoline Injection Systems for Personal
Planes". The ad is not dated, but looks to be from the 1950s.

I also have a "Fuel Injection Service Manual" dated 1 March 1941 from
the Fuel Injection Corp, Muskegon, MI. This system was used on aircraft
piston engines.


And a whole bunch of patents. The most interesting is "Fuel Injector
Apparatus for Internal Combustion Engine", 2,839,040, issued 17 June
1954. This goes into the control laws needed to properly utilize the
engine. (Go to http://www.pat2pdf.org to get the patent.)


And I hope that your motor oil was not a detergent oil. If so,
you want to wash it out before running it again. Detergent oils should
only be used where there is recirculation through a filter.

Hmm. I'll get better oil. Too-heavy oil would cause heating, but I'm
still suspicious of the spindle bearings. It may be simply some rust
that will vanish into the oil with use, but I think I will still take
the spindle apart.

Agreed. But be careful -- a clean workspace over a tray, in
case a bunch of needle rollers fall out, or a spring launches parts or
itself.

As described above, I took the spindle apart without surprise of
difficulty, or necessity of medical attention.

I don't think that this spindle needs real "spindle oil". The oiling
system was interesting. There are two wool felt oilers, one per end,
resting on tapered parts of the spindle axle. Both had a waistband of
heavy thread right where contact is made with the taper. I can't tell
if this was an original, or added by Grandfather. It looks like carpet
thread, and is attached to the wick by being sewn through the wick
(which is cylindrical).

I think that oil is wicked to the taper, and propelled towards
increasing diameters by centrifugal force, leading the oil to circulate
through the bearings enough to keep them lubricated. This will work far
above the speed at which splash lubrication fails.


(I remember the MGA shop manual when discussing disassembling
the transmission saying:

"Withdraw the three sliding rods and forks. Note the three
balls and springs released in consequence."

"released" actually means launched hard enough to bruise, if you don't
have several layers of cloth to catch them. And if you are not
sufficiently forewarned, they vanish into the weeds surrounding where I
worked on the car. No -- I didn't lose them, but I did get a bit of a
surprise. These were the detent balls which engaged notches in the rods
which slid the gears inside to engage the synchromesh rings.

Been there, done that. Cameras are like that too, although physical
bruises are uncommon.


Joe Gwinn

According to Joseph Gwinn :

In article ,
(DoN. Nichols) wrote:

O.K. I've had to jump through hoops, as the newsreader timed
out and expired your article while I was down in the shop gathering
information for this followup.

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

Yes -- but some styles of bearings are no longer made.
Certainly this is true for the bearings in the spindle of my Sanford
surface grinder.

[ ... ]

I took the spindle apart without difficulty. The bearings consist of
two ball bearings, one at each end, with a fingered flat disk spring at
one end taking up axial play. The bearing races are very thin, and are
pressed into place on the spindle (one end) and a spindle housing cap
(the other end). It does not look possible to remove the pressed-in
bearings without destroying the bearings (by forcing the balls into the
races), and the races are so thin I have to believe that they are
special-order.

Somewhat as I feared.

I think one replaces the assembly, not the bearing.

Are the bearings two-part, so you can remove the spindle from
the main casting?

The good news is that the bearings are OK, but were pretty dirty.

O.K. One of the nicest ways to clean small precision bearings
that I have found is a vapor degreaser. You boil a solvent (I used
Freon TF back when it was readily available -- or 1,1,1 Trichlor), and
put a double-walled liner at the top which gets cold water run through
it so it condenses the solvent and drips it back into the reservoir.

You could probably do a pretty good job with alcohol -- except
for the risk of igniting the vapors.

You lower the thing to be cleaned (usually in an open stainless steel
wire basket) into the vapor at the top, and the solvent condenses on it,
carries away old lube and particles, and drips into the reservoir. From
there, it is boiled again, and repeats the cycle, with only clean
solvent vapor reaching the object to be cleaned. You might need a pass
through an ultrasonic cleaner to dislodge particulate contamination, of
course.

The bearing pressed onto the spindle doesn't seem fully seated, and so
when the spindle body caps are fully screwed down, the axial takeup
spring is flattened. When the spindle is run at high speed and heats
up, the axial pressure on the bearings grows, increasing drag, causing
more heating, etc. This is what I observed when I first rat it at full
speed.

The current fix is to fully tighten the spindle cap that tends to
unscrew itself, and leave the other spindle cap loose by one turn.

Hmm ... use a feeler gauge to measure the gap, and cut a piece
of shim stock to serve as a spacer, so you can tighten it firmly without
crushing the bearings.

For the record, both spindle bearing caps are right-hand threaded. I
used the tips of a pair of needle-node pliers as a spanner wrench. The
caps turned easily. I did see some faint marks left by a pipe wrench on
the caps. Anyway, disassembly and reassembly were easy.

O.K. I've got some hinged pin spanners (which I use for the hub
on my surface grinder) which should work well on it, if I need to get
into it.

[ ... ]

Yes -- but they still might not be still in production. The
later ones appear to have a larger diameter spindle, with extensions
screwing in and locking with a taper.

OK. I have not had mine apart yet. Are you talking about the motor
bearings?

There, I am talking about the spindle bearings. On mine, there
is a projecting section of perhaps 1/2" (not measured), with a following
unthreaded section of 1/4", and finally a thread which appears to be
1/4-32 thread (though I kept getting not quite right measurements which
suggested that it was somewhere between 32 TPI and 30 TPI. Perhaps it
was a 1/4x8mm thread, which would work out to be 31.75 TPI. Well ... it
is now 32 TPI for sure, thanks to a die. :-)

Mine has an unthreaded nose with axial hole and grub screw.

Hmm ... "grub screw"? You're posting from the UK? I think that
is mostly a UK term. :-)

[ ... ]

Anyway -- the spindle adaptors shown in the eBay auction which
started this thread have a male thread with a taper, which apparently
threads into a somewhat larger hollow spindle. Whether the change in
design was forced by the original bearings becoming unavailable, or was
a voluntary change -- which *may* have taken the demand for the bearings
low enough so they are no longer made. Both are possible. Of course,
they are for a different model -- and probably a much later model than
ours.

From the current Dumore catalog, they had an assortment of spindles, and
the user was expected to change spindles as needed. So, there will be
many kinds of spindle floating around, but they should all fit the
grinder.

Except that those had the entire spindle cartridge removable
from the frame, I believe. If you can't get the bearings off the
spindle, and can't get the spindle out of the cylindrical part of the
housing, then you can't change spindles, I believe.

FWIW -- my complete model number is 11-011.

[ ... ]

I just looked at the unit. I think it would be hard to keep a
quarter-circle spanner on that. I would guess that a piece of thick
sheet metal with two teeth coming in 180 degrees apart would work
better.

Perhaps -- except that I'm not sure that it could be fitted into
the slots while the pulley is in place. Perhaps so.

On mine it can, so long as the sheet metal isn't too thick. The gap is
0.200" or more, and the tool needn't be more than 0.100" thick. It
could be made from a piece of oil-hardening steel.

O.K. That is exactly what I was expecting to make it from.
Though with the ring spanner, I probably won't need to make one right
away. :-)

I looked closely at the smaller pulley when I had it off. The corners
of the slot where the wrench would go are buggered up, and look like
someone tried to use and ordinary wrench on them.

O.K. I can believe that. :-)

Yes -- there was some interesting gummed oil under the pulley on
the spindle when I finally got it off.

My grandfather must have bought the unit in the late 1940s.

O.K. I have no real idea when mine was made.

I'm guessing that my Grandfather got this unit used and incomplete, in
the 1950s.

O.K. Mine, I got used and incomplete at Cabin Fever (or was it
Iron Fever) a bit over a year ago.

[ ... ]

While I don't have good woods for the task -- just whatever is
used to make cheap 2x4s these days -- a bit too soft, I think.

The local Home Despot carries Oak, which is what I used. Oak flooring
cutoffs are often available. Likewise, Maple.

O.K. Maple I would save for use repairing concertinas, not for
one-off tools.

I did
have to go to a vise because the small pulley was slipping inside with
just a hand grip -- though I have not reduced the size of the OD of the
ring enough yet.

But -- with the vise, it worked.

Big vice, big hammer -- tools to live by.

Well ... not too big a vise in this case. It is a drill-press
vice from Craftsman from about 1970 or so. One with the ability to
mount it at an angle to the surface. Mostly, it had a big enough jaw
opening (barely), it was heavy enough for my task, and it was easy to
get to at the moment. :-)

[ ... ]

Mine is olive drab, all steel, 12.5" wide by 7.5" deep by 7" high, with
drop front.

O.K. No drop front on mine. I have to loosen the bolt through
the compound mount, swing the motor forward against the spring, and
slide the T-slot adaptor out backwards to get it out. I suspect that I
would prefer the drop front case -- but I have what I have.

Does the box say Dumore? Mine does not have any indication of a maker.

It certainly does. The OD ones were government issue to the
Army, and would probably not have maker's names on them. I wonder
whether that drop-front design was part of an Army spec to make it
easier to get to under certain storage conditions? I've only seen it
(so far) on the OD cases.

A random collection of stones et al are included, but no pulleys aside
from those on the grinder.

I think for that series, only those two pulleys are supposed to
be used. The metal label on the motor show only two speeds -- with
large pulley on the motor, and with small pulley on the motor -- no
other choices. (Still better than a toolpost grinder which someone
found on one of the small lathe sites which has only a single speed, and
mounts only for wheel stones with holes, not for ones with shanks.)

I wondered about the pulleys, because current grinders from Dumore show
more than two sizes.

Right - they do.

What speeds are quoted on your grinder? Mine says nothing.

Motor first:

15,500 RPM no load
8,000 RPM full load.

Pulleys
Wheel size RPM Spindle Motor
=====================================
1/8" to 3/4" 30,000 #1 #2
2" 6,900 #2 #1

For a quick-and-dirty web page showing details of the label,
plus other features of the grinder and what I am making for it, see:

http://www2.d-and-d.com/PROJECTS/TP_GRINDER/index.html

I also need to make a holder for a truing diamond to hold in the
lathe chuck -- or in collets. But the machine is almost ready to use.
Then the question is how long can I resist using it, since I don't like
to expose the lathe to the grinding grit if I don't have to.

Set it up like surgery, with a sheet of plastic covering everything
except what absolutely must poke through?

Reasonable. I've read suggestions for covering everything with
several layers of wet newspaper, so the abrasive will stick to the
newspaper.

[ ... ]

What is the swing on this lathe?

12" (x24" between centers). A Clausing 5418 from 1957, if you
care.

Nothing to be ashamed of here, Clausing. Someday.

I'm quite pleased with it. It came with a bed turret (with
matching serial number) and no normal tailstock. I had to chase down a
replacement tailstock to bring it into full service -- though I get
quite a bit of use out of the turret.

[ ... ]

Nice work. One trick to get that kind of precision is to set
the compound at 5.7106 degrees (as close as you can get, at least), and
for every 0.001" you crank the compound feed, you move 0.0001" closer to
the axis. (If you care, that decimal degrees comes out to be:

5 degrees, 42 minutes, 38 seconds

Good luck on the typical compound angle scale. :-)

It's a nice trick, even if one cannot set this on the angle scale. I
would just set it to something, measure the effect of advancing by a set
amount, and then use a hand calculator to figure out what to do to
achieve a specified effect.

Actually -- setting it to 5-3/4 degrees by eye should get you
close enough. You are only going to be making very small reductions in
diameter, so frequent checking with a good micrometer should suffice in
addition to this. This simply lets you make adjustments in finer steps,
and it would be useless for turning, as there is often more spring than
that in even a good rigid lathe.

[ ... ]

My recollection is that it was the 1957 model year Corvette, but I have
not found any documents.

O.K. That was pretty close to the start of the Corvette line,
wasn't it? And the same for the Ford Thunderbird line, for that matter.


It turns out that the bread and butter was fuel injection systems for
general aviation engines.

O.K. So this was not just your grandfather, but the company for
which he worked?

I have an ad from the Ex-Cell-O Corporation in Detroit (where
Grandfather lived) for their "Gasoline Injection Systems for Personal
Planes". The ad is not dated, but looks to be from the 1950s.

O.K. "Personal Planes" sounds as strange now as "Personal
Computer" must have sounded then -- though there are still personal
planes, they are getting harder and harder to afford.

I also have a "Fuel Injection Service Manual" dated 1 March 1941 from
the Fuel Injection Corp, Muskegon, MI. This system was used on aircraft
piston engines.

O.K.

And a whole bunch of patents. The most interesting is "Fuel Injector
Apparatus for Internal Combustion Engine", 2,839,040, issued 17 June
1954. This goes into the control laws needed to properly utilize the
engine. (Go to http://www.pat2pdf.org to get the patent.)

Too much more to do tonight. Well ... I just took a look at it,
and was reminded how difficult I've found it to follow patent
descriptions of almost anything -- including electronic circuits for
which *I* hold the patent. :-)

[ ... ]

Agreed. But be careful -- a clean workspace over a tray, in
case a bunch of needle rollers fall out, or a spring launches parts or
itself.

As described above, I took the spindle apart without surprise of
difficulty, or necessity of medical attention.

Good.

I don't think that this spindle needs real "spindle oil". The oiling
system was interesting. There are two wool felt oilers, one per end,
resting on tapered parts of the spindle axle. Both had a waistband of
heavy thread right where contact is made with the taper. I can't tell
if this was an original, or added by Grandfather. It looks like carpet
thread, and is attached to the wick by being sewn through the wick
(which is cylindrical).

Hmm ... I really think that you still want spindle oils for
this, not motor oils.

I think that oil is wicked to the taper, and propelled towards
increasing diameters by centrifugal force, leading the oil to circulate
through the bearings enough to keep them lubricated. This will work far
above the speed at which splash lubrication fails.

Did you figure out what the central oil port does? Perhaps it
provides a reservoir to replenish the oil from the wicks, and you are
only expected to remove the caps at the ends to replace the wicks?


(I remember the MGA shop manual when discussing disassembling
the transmission saying:

"Withdraw the three sliding rods and forks. Note the three
balls and springs released in consequence."

"released" actually means launched hard enough to bruise, if you don't
have several layers of cloth to catch them. And if you are not
sufficiently forewarned, they vanish into the weeds surrounding where I
worked on the car. No -- I didn't lose them, but I did get a bit of a
surprise. These were the detent balls which engaged notches in the rods
which slid the gears inside to engage the synchromesh rings.

Been there, done that. Cameras are like that too, although physical
bruises are uncommon.

Yes -- the springs are not nearly as strong. :-) I've worked on
them, too.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote in message
...
According to Joseph Gwinn :

SNIP
FWIW -- my complete model number is 11-011.
It certainly does. The OD ones were government issue to the
Army, and would probably not have maker's names on them. I wonder
whether that drop-front design was part of an Army spec to make it
easier to get to under certain storage conditions? I've only seen it
(so far) on the OD cases.

What speeds are quoted on your grinder? Mine says nothing.

Motor first:

15,500 RPM no load
8,000 RPM full load.

Pulleys
Wheel size RPM Spindle Motor
=====================================
1/8" to 3/4" 30,000 #1 #2
2" 6,900 #2 #1

For a quick-and-dirty web page showing details of the label,
plus other features of the grinder and what I am making for it, see:

http://www2.d-and-d.com/PROJECTS/TP_GRINDER/index.html

MORE SNIPPAGE
Don,
I have the same TPG as yours. Same model number anyway. Mine is in a Dark
Grey box with just the top opening lid..no drop front. I have the collett
adapter and the manual that came with it if you need any info from that I
would be happy to scan/measure or whatever.
FWIW the Lubrication instructions say to use 25 to 50 drops of Dumore No 0
High speed oil every 10 hours of operation. The oil is added to the Gits
snap cap oiler located in front of the tool post. The 2 screws on the ends
of the spindle housing are for the oil wicks and they do have a thread
wraped around the felt to ride on the spindle tapers. Inside is a felt
cylinder that is called the oil retainer.

The collett adapter is a threaded sleeve type thing that has the collett
chuck on one end and is threaded internally to screw onto the spindle.
Looks a lot like somebody cut the end off a dremel only a bit larger OD on
the shaft. It is counter bored so it threads up to the sholder on the
spindle.

If any more info would help let me know. I think the only thing mine
dosen't have is the scatter guard for the OD wheels. The parts list dosen't
show one but some of the ictures do.

Glenn Neff
Medford, OR

In article ,
says...


I took the spindle apart without difficulty. The bearings consist of
two ball bearings, one at each end, with a fingered flat disk spring at
one end taking up axial play. The bearing races are very thin, and are
pressed into place on the spindle (one end) and a spindle housing cap
(the other end). It does not look possible to remove the pressed-in
bearings without destroying the bearings (by forcing the balls into the
races), and the races are so thin I have to believe that they are
special-order.

I wouldn't assume that the bearings are not standards without checking.
For example, 25mm ID single row bearings are available with ODs from
32mm to 80mm. NTN has a good online search tool, but if NTN doesn't list
the bearing don't assume it's not available from another mfr.

http://www.ntnamerica.com/products/N...l_Bearings.htm

The good news is that the bearings are OK, but were pretty dirty.

They may be usable. If they've been run at all in that condition chances
are they're not OK, if by OK you mean up to specs.

Ned Simmons

According to Glenn :

"DoN. Nichols" wrote in message
...
According to Joseph Gwinn :

SNIP
FWIW -- my complete model number is 11-011.

[ ... ]

Don,
I have the same TPG as yours. Same model number anyway. Mine is in a Dark
Grey box with just the top opening lid..no drop front.

Instead of the hammertone blue box which I have. I don't know
whether that makes yours or mine older. :-)

I have the collett
adapter and the manual that came with it if you need any info from that I
would be happy to scan/measure or whatever.

Both would be lovely to have. I presume that the collet adaptor
screws over the arbor for the plain wheels? I was just about to try
making one from scratch -- after dealing with the income tax torture,
which we just started. :-)

The major problem is that I can't receive e-mails larger than
30K -- as a means of keeping viruses out of some mailing lists which I
run.

An FTP site, or a web site would help. Perhaps you could
upload them to the dropbox (http://www.metalworking.com), and I could
pick them up from there? That would allow others to benefit from them
as well.

If you would prefer to not do that -- could you burn a CD-ROM of
the scans and snail-mail it? (There should be plenty of room on a
CD-ROM for everything needed and then some -- even if you scan for
output to a 600 DPI printer. :-) The manual for my Clausing lathe,
scanned to TIF for such a printer, converted to PostScript, and from
there to PDF results in a total file size of 6,964,511 -- about 1/100th
of a CD-ROM. :-)

FWIW the Lubrication instructions say to use 25 to 50 drops of Dumore No 0
High speed oil every 10 hours of operation. The oil is added to the Gits
snap cap oiler located in front of the tool post. The 2 screws on the ends
of the spindle housing are for the oil wicks and they do have a thread
wraped around the felt to ride on the spindle tapers. Inside is a felt
cylinder that is called the oil retainer.

O.K. "No. 0 High speed oil" sounds like a very thin spindle oil
to me, so what I got for my surface grinder would be about right.

The collett adapter is a threaded sleeve type thing that has the collett
chuck on one end and is threaded internally to screw onto the spindle.
Looks a lot like somebody cut the end off a dremel only a bit larger OD on
the shaft. It is counter bored so it threads up to the sholder on the
spindle.

That sounds like what I was planning to make. What is the
overall length to the end of the collet? (This will give me a target to
shoot for.)

If any more info would help let me know. I think the only thing mine
dosen't have is the scatter guard for the OD wheels. The parts list dosen't
show one but some of the ictures do.

Since I don't have the manual, I don't have the parts list
either. But I saw guards in some of the photos on the DuMore web site
when I tried to find information and really did not feel like spinning
up a larger wheel without one, so I made one to fit. (Turned from some
3-1/2" diameter aluminum. You probably visited the quick-and-dirty web
page and saw one shot of it, at least. If you want, I can send the
dimensions which I worked to as a drawing.

BTW -- My e-mail address is valid, if you want to take this
off line -- though we've got at least one other in the thread
who can benefit from what you know as well.

Thanks,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
Ned Simmons wrote:

In article ,
says...


I took the spindle apart without difficulty. The bearings consist of
two ball bearings, one at each end, with a fingered flat disk spring at
one end taking up axial play. The bearing races are very thin, and are
pressed into place on the spindle (one end) and a spindle housing cap
(the other end). It does not look possible to remove the pressed-in
bearings without destroying the bearings (by forcing the balls into the
races), and the races are so thin I have to believe that they are
special-order.

I wouldn't assume that the bearings are not standards without checking.
For example, 25mm ID single row bearings are available with ODs from
32mm to 80mm. NTN has a good online search tool, but if NTN doesn't list
the bearing don't assume it's not available from another mfr.

http://www.ntnamerica.com/products/N...l_Bearings.htm

OK. I'll check. If I have new bearings in hand, I won't care that I
have to destroy the old ones to remove them. If I can spare the spindle
axle.


The good news is that the bearings are OK, but were pretty dirty.

They may be usable. If they've been run at all in that condition chances
are they're not OK, if by OK you mean up to specs.

They feel pretty smooth now. Nor do I see anything bad on the balls.
Cannot see the ball tracks on the races, though.

Joe Gwinn

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :

In article ,
(DoN. Nichols) wrote:

O.K. I've had to jump through hoops, as the newsreader timed
out and expired your article while I was down in the shop gathering
information for this followup.

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

Yes -- but some styles of bearings are no longer made.
Certainly this is true for the bearings in the spindle of my Sanford
surface grinder.

[ ... ]

I took the spindle apart without difficulty. The bearings consist of
two ball bearings, one at each end, with a fingered flat disk spring at
one end taking up axial play. The bearing races are very thin, and are
pressed into place on the spindle (one end) and a spindle housing cap
(the other end). It does not look possible to remove the pressed-in
bearings without destroying the bearings (by forcing the balls into the
races), and the races are so thin I have to believe that they are
special-order.

Somewhat as I feared.

I think one replaces the assembly, not the bearing.

Are the bearings two-part, so you can remove the spindle from
the main casting?

No, but one can nonetheless remove the spindle without difficulty.

The trick is that one bearing (including both races, balls, and ball
retainer) is pressed onto the spindle, while the other bearing (ditto)
is pressed into one spindle body cap. When one unscrews the body caps
(the ones with the holes for the spanner wrench), one can pull one cap
off the spindle axle, allowing the spindle to be pulled out of the body.


The good news is that the bearings are OK, but were pretty dirty.

O.K. One of the nicest ways to clean small precision bearings
that I have found is a vapor degreaser. You boil a solvent (I used
Freon TF back when it was readily available -- or 1,1,1 Trichlor), and
put a double-walled liner at the top which gets cold water run through
it so it condenses the solvent and drips it back into the reservoir.

You could probably do a pretty good job with alcohol -- except
for the risk of igniting the vapors.

You lower the thing to be cleaned (usually in an open stainless steel
wire basket) into the vapor at the top, and the solvent condenses on it,
carries away old lube and particles, and drips into the reservoir. From
there, it is boiled again, and repeats the cycle, with only clean
solvent vapor reaching the object to be cleaned. You might need a pass
through an ultrasonic cleaner to dislodge particulate contamination, of
course.

I thought of building a little vapor degreaser as described above that
would use some available but flammable solvent, and running it only in
the middle of the back yard. Someday.

In the meantime, I soaked it in WD-40 plus acetone, spinning the bearing
while immersed in solvent, and blew the bearing off with compressed air.


The bearing pressed onto the spindle doesn't seem fully seated, and so
when the spindle body caps are fully screwed down, the axial takeup
spring is flattened. When the spindle is run at high speed and heats
up, the axial pressure on the bearings grows, increasing drag, causing
more heating, etc. This is what I observed when I first ran it at full
speed.

The current fix is to fully tighten the spindle cap that tends to
unscrew itself, and leave the other spindle cap loose by one turn.

Hmm ... use a feeler gauge to measure the gap, and cut a piece
of shim stock to serve as a spacer, so you can tighten it firmly without
crushing the bearings.

The lip isn't very deep. Perhaps a piece of copper wire will suffice.

Or, perhaps I can press the bearing race into place.


For the record, both spindle bearing caps are right-hand threaded. I
used the tips of a pair of needle-node pliers as a spanner wrench. The
caps turned easily. I did see some faint marks left by a pipe wrench on
the caps. Anyway, disassembly and reassembly were easy.

O.K. I've got some hinged pin spanners (which I use for the hub
on my surface grinder) which should work well on it, if I need to get
into it.

I would just have at it, and use the opportunity to clean the crud out
of the bearings. It isn't all that tricky or hard; I've had zero
trouble.


Yes -- but they still might not be still in production. The
later ones appear to have a larger diameter spindle, with extensions
screwing in and locking with a taper.

OK. I have not had mine apart yet. Are you talking about the motor
bearings?

There, I am talking about the spindle bearings. On mine, there
is a projecting section of perhaps 1/2" (not measured), with a following
unthreaded section of 1/4", and finally a thread which appears to be
1/4-32 thread (though I kept getting not quite right measurements which
suggested that it was somewhere between 32 TPI and 30 TPI. Perhaps it
was a 1/4x8mm thread, which would work out to be 31.75 TPI. Well ... it
is now 32 TPI for sure, thanks to a die. :-)

Mine has an unthreaded nose with axial hole and grub screw.

Hmm ... "grub screw"? You're posting from the UK? I think that
is mostly a UK term. :-)

Well, the Boston area, but a Boston accent (which I don't have but my
wife does have) is really a form of London Cockney.


Anyway -- the spindle adaptors shown in the eBay auction which
started this thread have a male thread with a taper, which apparently
threads into a somewhat larger hollow spindle. Whether the change in
design was forced by the original bearings becoming unavailable, or was
a voluntary change -- which *may* have taken the demand for the bearings
low enough so they are no longer made. Both are possible. Of course,
they are for a different model -- and probably a much later model than
ours.

From the current Dumore catalog, they had an assortment of spindles, and
the user was expected to change spindles as needed. So, there will be
many kinds of spindle floating around, but they should all fit the
grinder.

Except that those had the entire spindle cartridge removable
from the frame, I believe. If you can't get the bearings off the
spindle, and can't get the spindle out of the cylindrical part of the
housing, then you can't change spindles, I believe.

Yes, but I think that these spindles are removable, as described above.


FWIW -- my complete model number is 11-011.

Mine is Type 11G, No 1059, 115 Volts. All other info blocks on the tag
are blank. Probably bought for the US Army to a govt spec, and later
sold as surplus to my Grandfather.


Yes -- there was some interesting gummed oil under the pulley on
the spindle when I finally got it off.

My grandfather must have bought the unit in the late 1940s.

O.K. I have no real idea when mine was made.

I'm guessing that my Grandfather got this unit used and incomplete, in
the 1950s.

O.K. Mine, I got used and incomplete at Cabin Fever (or was it
Iron Fever) a bit over a year ago.

[ ... ]

While I don't have good woods for the task -- just whatever is
used to make cheap 2x4s these days -- a bit too soft, I think.

The local Home Despot carries Oak, which is what I used. Oak flooring
cutoffs are often available. Likewise, Maple.

O.K. Maple I would save for use repairing concertinas, not for
one-off tools.

Well, lots of special-purpose tools were made of maple, and it isn't all
that more costly than oak in small quantities at HD, and the grain is
very fine and uniform.


I did
have to go to a vise because the small pulley was slipping inside with
just a hand grip -- though I have not reduced the size of the OD of the
ring enough yet.

But -- with the vise, it worked.

Big vice, big hammer -- tools to live by.

Well ... not too big a vise in this case. It is a drill-press
vice from Craftsman from about 1970 or so. One with the ability to
mount it at an angle to the surface. Mostly, it had a big enough jaw
opening (barely), it was heavy enough for my task, and it was easy to
get to at the moment. :-)

I'm not impressed. Real vices weigh 100# min. Like anvils.


Mine is olive drab, all steel, 12.5" wide by 7.5" deep by 7" high, with
drop front.

O.K. No drop front on mine. I have to loosen the bolt through
the compound mount, swing the motor forward against the spring, and
slide the T-slot adaptor out backwards to get it out. I suspect that I
would prefer the drop front case -- but I have what I have.

Does the box say Dumore? Mine does not have any indication of a maker.

It certainly does. The OD ones were government issue to the
Army, and would probably not have maker's names on them. I wonder
whether that drop-front design was part of an Army spec to make it
easier to get to under certain storage conditions? I've only seen it
(so far) on the OD cases.

Another indication that my unit was made to some generic govt spec.


A random collection of stones et al are included, but no pulleys aside
from those on the grinder.

I think for that series, only those two pulleys are supposed to
be used. The metal label on the motor show only two speeds -- with
large pulley on the motor, and with small pulley on the motor -- no
other choices. (Still better than a toolpost grinder which someone
found on one of the small lathe sites which has only a single speed, and
mounts only for wheel stones with holes, not for ones with shanks.)

I wondered about the pulleys, because current grinders from Dumore show
more than two sizes.

Right - they do.

What speeds are quoted on your grinder? Mine says nothing.

Motor first:

15,500 RPM no load
8,000 RPM full load.

This sounds plausible, from the sound while it spins.


Pulleys
Wheel size RPM Spindle Motor
=====================================
1/8" to 3/4" 30,000 #1 #2
2" 6,900 #2 #1

My pulleys are 2.165" and 0.906" in diameter, so the available ratios
are 2.39:1 and 0.418:1, for loaded speeds of 19,117 rpm and 3,348 rpm
respectively. No-load speeds are about twice that.


For a quick-and-dirty web page showing details of the label,
plus other features of the grinder and what I am making for it, see:

http://www2.d-and-d.com/PROJECTS/TP_GRINDER/index.html

Mine seems much more spartan.


I also need to make a holder for a truing diamond to hold in the
lathe chuck -- or in collets. But the machine is almost ready to use.
Then the question is how long can I resist using it, since I don't
like to expose the lathe to the grinding grit if I don't have to.

Set it up like surgery, with a sheet of plastic covering everything
except what absolutely must poke through?

Reasonable. I've read suggestions for covering everything with
several layers of wet newspaper, so the abrasive will stick to the
newspaper.

Wet newspaper will rust things, but I suppose that's not as bad as
abrasive grit everywhere.

With the plastic covering, the classic trick is to use sheet
polyethylene at least 0.002" thick, and force the sheet down on whatever
must penetrate, allowing the punctured sheet to pull tight around
whatever sticks through it.


What is the swing on this lathe?

12" (x24" between centers). A Clausing 5418 from 1957, if you
care.

Nothing to be ashamed of here, Clausing. Someday.

I'm quite pleased with it. It came with a bed turret (with
matching serial number) and no normal tailstock. I had to chase down a
replacement tailstock to bring it into full service -- though I get
quite a bit of use out of the turret.

Hmm. I have iron envy.


Nice work. One trick to get that kind of precision is to set
the compound at 5.7106 degrees (as close as you can get, at least), and
for every 0.001" you crank the compound feed, you move 0.0001" closer to
the axis. (If you care, that decimal degrees comes out to be:

5 degrees, 42 minutes, 38 seconds

Good luck on the typical compound angle scale. :-)

It's a nice trick, even if one cannot set this on the angle scale. I
would just set it to something, measure the effect of advancing by a set
amount, and then use a hand calculator to figure out what to do to
achieve a specified effect.

Actually -- setting it to 5-3/4 degrees by eye should get you
close enough. You are only going to be making very small reductions in
diameter, so frequent checking with a good micrometer should suffice in
addition to this. This simply lets you make adjustments in finer steps,
and it would be useless for turning, as there is often more spring than
that in even a good rigid lathe.

Right. This only works for grinding on anything other than a Hardinge.


My recollection is that it was the 1957 model year Corvette, but I have
not found any documents.

O.K. That was pretty close to the start of the Corvette line,
wasn't it? And the same for the Ford Thunderbird line, for that matter.

I don't recall.


It turns out that the bread and butter was fuel injection systems for
general aviation engines.

O.K. So this was not just your grandfather, but the company for
which he worked?

Both. I don't think that Grandfather was an employee, as all his
patents were his, and were not assigned to anybody.


I have an ad from the Ex-Cell-O Corporation in Detroit (where
Grandfather lived) for their "Gasoline Injection Systems for Personal
Planes". The ad is not dated, but looks to be from the 1950s.

O.K. "Personal Planes" sounds as strange now as "Personal
Computer" must have sounded then -- though there are still personal
planes, they are getting harder and harder to afford.

I also have a "Fuel Injection Service Manual" dated 1 March 1941 from
the Fuel Injection Corp, Muskegon, MI. This system was used on aircraft
piston engines.

O.K.

And a whole bunch of patents. The most interesting is "Fuel Injector
Apparatus for Internal Combustion Engine", 2,839,040, issued 17 June
1954. This goes into the control laws needed to properly utilize the
engine. (Go to http://www.pat2pdf.org to get the patent.)

Too much more to do tonight. Well ... I just took a look at it,
and was reminded how difficult I've found it to follow patent
descriptions of almost anything -- including electronic circuits for
which *I* hold the patent. :-)

I certainly agree, but I've found the patent literature to be quite
useful over the years.

I bet there is a patent covering the Dumore grinder. Are there any
patent numbers on anything? My unit has nothing, but then again it's
pretty spartan.


Agreed. But be careful -- a clean workspace over a tray, in
case a bunch of needle rollers fall out, or a spring launches parts or
itself.

As described above, I took the spindle apart without surprise of
difficulty, or necessity of medical attention.

Good.

I don't think that this spindle needs real "spindle oil". The oiling
system was interesting. There are two wool felt oilers, one per end,
resting on tapered parts of the spindle axle. Both had a waistband of
heavy thread right where contact is made with the taper. I can't tell
if this was an original, or added by Grandfather. It looks like carpet
thread, and is attached to the wick by being sewn through the wick
(which is cylindrical).

Hmm ... I really think that you still want spindle oils for
this, not motor oils.

Hmm. I wonder what Dumore says about this. This spindle is pretty
fast, but then again this isn't a lathe headstock bearing either.

Another poster said that the carpet thread is original.


I think that oil is wicked to the taper, and propelled towards
increasing diameters by centrifugal force, leading the oil to circulate
through the bearings enough to keep them lubricated. This will work far
above the speed at which splash lubrication fails.

Did you figure out what the central oil port does? Perhaps it
provides a reservoir to replenish the oil from the wicks, and you are
only expected to remove the caps at the ends to replace the wicks?

That's my impression, although the covers over the two wicks are stamped
"oil".


(I remember the MGA shop manual when discussing disassembling
the transmission saying:

"Withdraw the three sliding rods and forks. Note the three
balls and springs released in consequence."

"released" actually means launched hard enough to bruise, if you don't
have several layers of cloth to catch them. And if you are not
sufficiently forewarned, they vanish into the weeds surrounding where I
worked on the car. No -- I didn't lose them, but I did get a bit of a
surprise. These were the detent balls which engaged notches in the rods
which slid the gears inside to engage the synchromesh rings.

Been there, done that. Cameras are like that too, although physical
bruises are uncommon.

Yes -- the springs are not nearly as strong. :-) I've worked on
them, too.

Did the MGA manual mention how to reassembly this little beauty?

I recall working on the front shocks for a MGB my then girlfriend owned.
These were the swing-arm shocks. I don't recall much about them except
that they were a bitch to install without damage to all concerned.

Joe Gwinn

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

I took the spindle apart without difficulty. The bearings consist of
two ball bearings, one at each end, with a fingered flat disk spring at
one end taking up axial play. The bearing races are very thin, and are
pressed into place on the spindle (one end) and a spindle housing cap
(the other end). It does not look possible to remove the pressed-in
bearings without destroying the bearings (by forcing the balls into the
races), and the races are so thin I have to believe that they are
special-order.

Somewhat as I feared.

I think one replaces the assembly, not the bearing.

Are the bearings two-part, so you can remove the spindle from
the main casting?

No, but one can nonetheless remove the spindle without difficulty.

The trick is that one bearing (including both races, balls, and ball
retainer) is pressed onto the spindle, while the other bearing (ditto)
is pressed into one spindle body cap. When one unscrews the body caps
(the ones with the holes for the spanner wrench), one can pull one cap
off the spindle axle, allowing the spindle to be pulled out of the body.

O.K. That sounds reasonable.

The good news is that the bearings are OK, but were pretty dirty.

O.K. One of the nicest ways to clean small precision bearings
that I have found is a vapor degreaser. You boil a solvent (I used
Freon TF back when it was readily available -- or 1,1,1 Trichlor), and
put a double-walled liner at the top which gets cold water run through
it so it condenses the solvent and drips it back into the reservoir.

You could probably do a pretty good job with alcohol -- except
for the risk of igniting the vapors.

[ ... ]

I thought of building a little vapor degreaser as described above that
would use some available but flammable solvent, and running it only in
the middle of the back yard. Someday.

That makes sense.

FWIW -- I can testify that silicone oil (supposedly
non-flammable) *will* ignite and burn if the vapors from a heated beaker
of it curl around into the still-hot elements of the hotplate on which
the beaker is sitting. (There was some dry ice in the beaker to hasten
it back to the starting point of a temperature coeficient run.) And,
when that vapor burns, the result is very fine sand all over the place. :-)

In the meantime, I soaked it in WD-40 plus acetone, spinning the bearing
while immersed in solvent, and blew the bearing off with compressed air.

O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

[ ... ]

Hmm ... use a feeler gauge to measure the gap, and cut a piece
of shim stock to serve as a spacer, so you can tighten it firmly without
crushing the bearings.

The lip isn't very deep. Perhaps a piece of copper wire will suffice.

Perhaps.

Or, perhaps I can press the bearing race into place.

That would be better if possible. Can you turn up a cylindrical
pusher to press only on the inner race?


For the record, both spindle bearing caps are right-hand threaded. I
used the tips of a pair of needle-node pliers as a spanner wrench. The
caps turned easily. I did see some faint marks left by a pipe wrench on
the caps. Anyway, disassembly and reassembly were easy.

O.K. I've got some hinged pin spanners (which I use for the hub
on my surface grinder) which should work well on it, if I need to get
into it.

I would just have at it, and use the opportunity to clean the crud out
of the bearings. It isn't all that tricky or hard; I've had zero
trouble.

O.K. -- Other than getting things fully back together with the
caps fully tightened. (Which I gather was a pre-existing condition. :-)
Perhaps there is some grit stuck between the inner race and the spindle?

[ ... ]

Mine has an unthreaded nose with axial hole and grub screw.

Hmm ... "grub screw"? You're posting from the UK? I think that
is mostly a UK term. :-)

Well, the Boston area, but a Boston accent (which I don't have but my
wife does have) is really a form of London Cockney.

O.K. I guess that you picked up the term from the net, then.

FWIW My wife is from the area too -- Salem.

[ ... ]

From the current Dumore catalog, they had an assortment of spindles, and
the user was expected to change spindles as needed. So, there will be
many kinds of spindle floating around, but they should all fit the
grinder.

Except that those had the entire spindle cartridge removable
from the frame, I believe. If you can't get the bearings off the
spindle, and can't get the spindle out of the cylindrical part of the
housing, then you can't change spindles, I believe.

Yes, but I think that these spindles are removable, as described above.

O.K. But the other fellow who has jumped into the thread has a
spindle like mine, and has screw-on collet adaptors -- not replaceable
spindles.

FWIW -- my complete model number is 11-011.

Mine is Type 11G, No 1059, 115 Volts. All other info blocks on the tag
are blank. Probably bought for the US Army to a govt spec, and later
sold as surplus to my Grandfather.

O.K. The OD drop-front cabinet suggests that you are right.

[ ... ]

While I don't have good woods for the task -- just whatever is
used to make cheap 2x4s these days -- a bit too soft, I think.

The local Home Despot carries Oak, which is what I used. Oak flooring
cutoffs are often available. Likewise, Maple.

O.K. Maple I would save for use repairing concertinas, not for
one-off tools.

Well, lots of special-purpose tools were made of maple, and it isn't all
that more costly than oak in small quantities at HD, and the grain is
very fine and uniform.

I had to go to a specialty wood shop to get my maple -- of
appropriate thickness for making replacement concertina pieces.

[ ... ]

Big vice, big hammer -- tools to live by.

Well ... not too big a vise in this case. It is a drill-press
vice from Craftsman from about 1970 or so. One with the ability to
mount it at an angle to the surface. Mostly, it had a big enough jaw
opening (barely), it was heavy enough for my task, and it was easy to
get to at the moment. :-)

I'm not impressed. Real vices weigh 100# min. Like anvils.

Agreed. Closer is the original Bridgeport vise which I have. I
*think* that is heavier than the import bench vise which is on one of
the workbenches.

[ ... ]

Does the box say Dumore? Mine does not have any indication of a maker.

It certainly does. The OD ones were government issue to the
Army, and would probably not have maker's names on them. I wonder
whether that drop-front design was part of an Army spec to make it
easier to get to under certain storage conditions? I've only seen it
(so far) on the OD cases.

Another indication that my unit was made to some generic govt spec.

Yep.

[ ... ]

I wondered about the pulleys, because current grinders from Dumore show
more than two sizes.

Right - they do.

What speeds are quoted on your grinder? Mine says nothing.

Motor first:

15,500 RPM no load
8,000 RPM full load.

This sounds plausible, from the sound while it spins.

You don't have a strobotac? I've recently discovered that they
are on eBay for fairly reasonable prices -- except that I already got
mine at a hamfest.

Pulleys
Wheel size RPM Spindle Motor
=====================================
1/8" to 3/4" 30,000 #1 #2
2" 6,900 #2 #1

My pulleys are 2.165" and 0.906" in diameter, so the available ratios
are 2.39:1 and 0.418:1, for loaded speeds of 19,117 rpm and 3,348 rpm
respectively. No-load speeds are about twice that.

Hmm ... I don't have the measurement for the larger pulley, but
the smaller one has a maximum diameter of 0.9245" -- measured to make
that ring spanner wrench.

For a quick-and-dirty web page showing details of the label,
plus other features of the grinder and what I am making for it, see:

http://www2.d-and-d.com/PROJECTS/TP_GRINDER/index.html

Mine seems much more spartan.

As fits government construction.

[ ... ]

Set it up like surgery, with a sheet of plastic covering everything
except what absolutely must poke through?

Reasonable. I've read suggestions for covering everything with
several layers of wet newspaper, so the abrasive will stick to the
newspaper.

Wet newspaper will rust things, but I suppose that's not as bad as
abrasive grit everywhere.

It will rust things *if*:

1) The surfaces are not first wiped down with Vactra No. 2.

2) The wet newspapers are left on for longer than a work day.

And -- of course -- the newspapers could be wet down with oil
instead of water. It would accomplish the same purpose, not risk rust,
and make the newspaper harder to dispose of. :-)

With the plastic covering, the classic trick is to use sheet
polyethylene at least 0.002" thick, and force the sheet down on whatever
must penetrate, allowing the punctured sheet to pull tight around
whatever sticks through it.

Reasonable.

[ ... ]

Nice work. One trick to get that kind of precision is to set
the compound at 5.7106 degrees (as close as you can get, at least), and
for every 0.001" you crank the compound feed, you move 0.0001" closer to
the axis. (If you care, that decimal degrees comes out to be:

5 degrees, 42 minutes, 38 seconds

Good luck on the typical compound angle scale. :-)

It's a nice trick, even if one cannot set this on the angle scale. I
would just set it to something, measure the effect of advancing by a set
amount, and then use a hand calculator to figure out what to do to
achieve a specified effect.

Actually -- setting it to 5-3/4 degrees by eye should get you
close enough. You are only going to be making very small reductions in
diameter, so frequent checking with a good micrometer should suffice in
addition to this. This simply lets you make adjustments in finer steps,
and it would be useless for turning, as there is often more spring than
that in even a good rigid lathe.

Right. This only works for grinding on anything other than a Hardinge.

Agreed. Though it works *sometimes* with really sharp cutters
and non work-hardening workpiece materials on the Clausing. When I want
to work to precise dimensions, I often use one of the carbide insert
tools from my Emco-Maier Compact-5/CNC. It is a very small 55 degree
diamond insert, and I lucked into a batch of inserts which are very
sharp and not TiN coated, so the edges are not rounded off. Certainly
the inserts which came with the lathe were not so sharp.

My recollection is that it was the 1957 model year Corvette, but I have
not found any documents.

O.K. That was pretty close to the start of the Corvette line,
wasn't it? And the same for the Ford Thunderbird line, for that matter.

I don't recall.

I believe that the two-seat Thunderbird started in 1956. I was
in high school then, in a small town in South Texas, and someone there
got one -- and was the focus of attention. Not too much later, 1959 I
think, Ford spoiled the T-bird by turning it into a four-seater. At
least the Vette remained two-seat all the way into the present.

It turns out that the bread and butter was fuel injection systems for
general aviation engines.

O.K. So this was not just your grandfather, but the company for
which he worked?

Both. I don't think that Grandfather was an employee, as all his
patents were his, and were not assigned to anybody.

O.K. Which explains why he had a shop at home, and could (and
did) do such precision work -- for the prototypes, so he was not
obligated to anyone else, and could license his patents to who he
wished.

[ ... ]

Too much more to do tonight. Well ... I just took a look at it,
and was reminded how difficult I've found it to follow patent
descriptions of almost anything -- including electronic circuits for
which *I* hold the patent. :-)

I certainly agree, but I've found the patent literature to be quite
useful over the years.

I bet there is a patent covering the Dumore grinder. Are there any
patent numbers on anything? My unit has nothing, but then again it's
pretty spartan.

Hmm The only data source which I have is the motor label, and
all it says on the subject is "Trade Mark Reg US Pat Off" in the upper
left and right corners. :-)

[ ... ]

Hmm ... I really think that you still want spindle oils for
this, not motor oils.

Hmm. I wonder what Dumore says about this. This spindle is pretty
fast, but then again this isn't a lathe headstock bearing either.

Another poster said that the carpet thread is original.

He also says that they told how much oil and what grade (which
they specified as their own brand, of course. And the oil is supposed
to only be added at the center.


I think that oil is wicked to the taper, and propelled towards
increasing diameters by centrifugal force, leading the oil to circulate
through the bearings enough to keep them lubricated. This will work far
above the speed at which splash lubrication fails.

Did you figure out what the central oil port does? Perhaps it
provides a reservoir to replenish the oil from the wicks, and you are
only expected to remove the caps at the ends to replace the wicks?

That's my impression, although the covers over the two wicks are stamped
"oil".

Hmm ... I don't remember any such markings on mine -- just the
screw-in caps with no markings. I at first expected them to allow me to
slide the end caps out when I loosened them. When that didn't happen, I
unscrewed one to find the wick. :-)

[ ... ]

Been there, done that. Cameras are like that too, although physical
bruises are uncommon.

Yes -- the springs are not nearly as strong. :-) I've worked on
them, too.

Did the MGA manual mention how to reassembly this little beauty?

Sure -- the same way they had to reassemble *any* part. The
last paragraph of each section would read:

"Reassembly is a reversal of the above."

:-)

It was possible to use a chunk of round steel stock (even an old bolt)
to press the bearings and springs in enough to get the rods started,
after which things were fine until you removed the rods again. :-)

I recall working on the front shocks for a MGB my then girlfriend owned.
These were the swing-arm shocks. I don't recall much about them except
that they were a bitch to install without damage to all concerned.

Hmm ... I replaced the ones on my second MGA (1600 Mk II), and I
don't remember it being particularly difficult -- unlike some other
things, including replacing the clutch plate and pressure plate. :-) For
*that*, you have to remove the engine and transmission as a unit. And
to do that as indicated by the manual, you have to remove the
transmission tunnel, and to remove *that* you first had to remove the
floorboards -- plywood floorboards secured by screws which stuck out far
enough through the floor to get dinged and rusted.

After doing it by the book *once*, I figured out how to remove
the motor and transmission without removing the trans tunnel. But it
required small hands and blind dexterity. (It still beat doing it as
intended. :-)

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

I thought of building a little vapor degreaser as described above that
would use some available but flammable solvent, and running it only in
the middle of the back yard. Someday.

That makes sense.

The plan was to use some vitrified power resistors as the boiler, and a
loop of copper tube soldered to the rim with garden-hose water flowing
through as the cooler.

That should do it. The longer the skirt of the chilled top, the
less vapor escapes (given protection from wind, of course).


FWIW -- I can testify that silicone oil (supposedly
non-flammable) *will* ignite and burn if the vapors from a heated beaker
of it curl around into the still-hot elements of the hotplate on which
the beaker is sitting. (There was some dry ice in the beaker to hasten
it back to the starting point of a temperature coefficient run.) And,
when that vapor burns, the result is very fine sand all over the place. :-)

I'll have to try this someday. In the backyard.

Be sure to have a CO2 fire extinguisher handy. I'm not sure
what a hose would do for that -- possibly float and spread the burning
silicone oil.

Note that this was a mix of two silicone oils -- one which was
normally used for measurement at -50C, and the other which was normally
used at +150C. The first would boil at the high temperature, and the
second would set up into a grease at the low end, making it hard to
equate the temperature at the thermometer with that in the device under
test. The low-temperature oil, when it hit the bubbles from the dry ice
in the beaker evaporated quickly, and spilled over the edge and curled
into the heating elements.

We would have been better off letting the beaker cool down on
its own -- but we had quite a few more devices to test -- ones returned
from the customer, because while they met specs at -50, +50, and +150C,
they were out of spec at some points between those temperatures.


In the meantime, I soaked it in WD-40 plus acetone, spinning the bearing
while immersed in solvent, and blew the bearing off with compressed air.

O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

How so?

It can spin up to a fast enough RPM so the centrifugal force (I
know -- there really is no such thing) will cause it to fly apart --
turning it into shrapnel -- and *you* into a target. I don't know
whether there is any size limit for this to happen, but it has been
known to happen and to harm or kill people nearby.

[ ... ]

Or, perhaps I can press the bearing race into place.

That would be better if possible. Can you turn up a cylindrical
pusher to press only on the inner race?

Not yet, but soon. There is a cylindrical sleeve already there. I
think it is supposed to rest on the bearing inner race on one end, and
one flange of the two that hold external grinding wheels on the other.

O.K.

[ ... ]

I would just have at it, and use the opportunity to clean the crud out
of the bearings. It isn't all that tricky or hard; I've had zero
trouble.

O.K. -- Other than getting things fully back together with the
caps fully tightened. (Which I gather was a pre-existing condition. :-)
Perhaps there is some grit stuck between the inner race and the spindle?

Yes, it was pre-existing, and I bet it was that way when Grandfather got
the unit. There is lots of dirt in the way at present.

O.K. You get yours back together properly, and then I will take
mine apart -- assuming that the manual does not turn out to say *don't*
in big bold letters. :-)


Mine has an unthreaded nose with axial hole and grub screw.

Hmm ... "grub screw"? You're posting from the UK? I think that
is mostly a UK term. :-)

[ ... ]

I did pick the term up from RCM. Sounds better than setscrew,

Well ... it works nicely if you understand where the term
originated -- but the "setscrew" term is more descriptive of the
function.

[ ... ]

O.K. But the other fellow who has jumped into the thread has a
spindle like mine, and has screw-on collet adaptors -- not replaceable
spindles.

I wonder. I think that all Series 11 grinders have removable spindles.

It may depend on what you call "removable". Certainly the ones
which started this thread were designed to screw into a hollow spindle
with a taper, based on the photos. (Hmm ... has that auction closed,
yet? :-)

[ ... ]

Well, lots of special-purpose tools were made of maple, and it isn't all
that more costly than oak in small quantities at HD, and the grain is
very fine and uniform.

I had to go to a specialty wood shop to get my maple -- of
appropriate thickness for making replacement concertina pieces.

Ouch. I bet it is *very* good wood. There must be other sources.

Probably -- but this is a nice quality wood, for not that bad a
price, and it is a lifetime supply for the parts which I need to make.

[ ... ]

15,500 RPM no load
8,000 RPM full load.

This sounds plausible, from the sound while it spins.

You don't have a strobotac? I've recently discovered that they
are on eBay for fairly reasonable prices -- except that I already got
mine at a hamfest.

Thought of it, haven't done it yet.

O.K. If you can -- try to pick up on another auction of FX-6A
flashlamps -- these darken with use, and are now *very* hard to find. I
finally won an auction for enough to keep me going for a while.

Pulleys
Wheel size RPM Spindle Motor
=====================================
1/8" to 3/4" 30,000 #1 #2
2" 6,900 #2 #1

My pulleys are 2.165" and 0.906" in diameter, so the available ratios
are 2.39:1 and 0.418:1, for loaded speeds of 19,117 rpm and 3,348 rpm
respectively. No-load speeds are about twice that.

Hmm ... I don't have the measurement for the larger pulley, but
the smaller one has a maximum diameter of 0.9245" -- measured to make
that ring spanner wrench.

I rechecked the diameters, this time with a micrometer (not a caliper).
They are 0.906" and 2.184" in diameter, more or less as reported.

O.K. This shows a difference between our TP grinders, as does
the nature of the spindle.

[ ... ]

It will rust things *if*:

1) The surfaces are not first wiped down with Vactra No. 2.

2) The wet newspapers are left on for longer than a work day.

Newsprint is somewhat acid. That's why it yellows so fast.

Yes -- but that is a *very* low amount.

Vactra #2 seems to be the universal elixer of machine tools.

Yep! You should always have plenty on hand, after all.

[ ... ]

Actually -- setting it to 5-3/4 degrees by eye should get you
close enough. You are only going to be making very small reductions in
diameter, so frequent checking with a good micrometer should suffice in
addition to this. This simply lets you make adjustments in finer steps,
and it would be useless for turning, as there is often more spring than
that in even a good rigid lathe.

Right. This only works for grinding on anything other than a Hardinge.

Agreed. Though it works *sometimes* with really sharp cutters
and non work-hardening workpiece materials on the Clausing. When I want
to work to precise dimensions, I often use one of the carbide insert
tools from my Emco-Maier Compact-5/CNC. It is a very small 55 degree
diamond insert, and I lucked into a batch of inserts which are very
sharp and not TiN coated, so the edges are not rounded off. Certainly
the inserts which came with the lathe were not so sharp.

Would HSS, well-sharpened, be better?

That depends on the material -- but it potentially would be.
This is good enough so I don't feel the need to make HSS tools for that
specific purpose.

[ ... ]

Both. I don't think that Grandfather was an employee, as all his
patents were his, and were not assigned to anybody.

O.K. Which explains why he had a shop at home, and could (and
did) do such precision work -- for the prototypes, so he was not
obligated to anyone else, and could license his patents to who he
wished.

Sounds right. Wonder what became of his lathe et al. I didn't inherit
any of it. Though I don't recall his basement being crowded with
machine tools. He must have had a machine shop or at least access
somewhere else.

O.K. Interesting that you wound up with the toolpost grinder.
Lucky for you.

[ ... ]

I bet there is a patent covering the Dumore grinder. Are there any
patent numbers on anything? My unit has nothing, but then again it's
pretty spartan.

Hmm The only data source which I have is the motor label, and
all it says on the subject is "Trade Mark Reg US Pat Off" in the upper
left and right corners. :-)

Protects only the trademark "Dumore".

Yep -- but that is all the information that I have from my
grinder. And I wonder how much of it would be patentable by that time.
Perhaps not enough to make it worth while hanging patent numbers on it,
if the patents were all expired.

[ ... ]

He also says that they told how much oil and what grade (which
they specified as their own brand, of course. And the oil is supposed
to only be added at the center.

Yes, Dumore type 0 oil, which sounds to be pretty low viscosity.

I wonder if one can buy new wicks.

I suspect that one would need to make new wicks at this point.
You can get appropriate felt from McMaster Carr for the task.

[ ... ]

Did the MGA manual mention how to reassembly this little beauty?

Sure -- the same way they had to reassemble *any* part. The
last paragraph of each section would read:

"Reassembly is a reversal of the above."

Unh.

:-)

Hmm ... I replaced the ones on my second MGA (1600 Mk II), and I
don't remember it being particularly difficult -- unlike some other
things, including replacing the clutch plate and pressure plate. :-) For
*that*, you have to remove the engine and transmission as a unit. And
to do that as indicated by the manual, you have to remove the
transmission tunnel, and to remove *that* you first had to remove the
floorboards -- plywood floorboards secured by screws which stuck out far
enough through the floor to get dinged and rusted.

After doing it by the book *once*, I figured out how to remove
the motor and transmission without removing the trans tunnel. But it
required small hands and blind dexterity. (It still beat doing it as
intended. :-)

Sadly, I never had the pleasure. GF got rid of that card first. Or
crushed it; don't recall which. Saved by the bell in any case.

O.K. The MGA was a fun car, and I suspect that the B was as
well. (I preferred the appearance of the A.)

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

I took the spindle apart without difficulty. The bearings consist of
two ball bearings, one at each end, with a fingered flat disk spring at
one end taking up axial play. The bearing races are very thin, and are
pressed into place on the spindle (one end) and a spindle housing cap
(the other end). It does not look possible to remove the pressed-in
bearings without destroying the bearings (by forcing the balls into the
races), and the races are so thin I have to believe that they are
special-order.

Somewhat as I feared.

I think one replaces the assembly, not the bearing.

Are the bearings two-part, so you can remove the spindle from
the main casting?

No, but one can nonetheless remove the spindle without difficulty.

The trick is that one bearing (including both races, balls, and ball
retainer) is pressed onto the spindle, while the other bearing (ditto)
is pressed into one spindle body cap. When one unscrews the body caps
(the ones with the holes for the spanner wrench), one can pull one cap
off the spindle axle, allowing the spindle to be pulled out of the body.

O.K. That sounds reasonable.

The good news is that the bearings are OK, but were pretty dirty.

O.K. One of the nicest ways to clean small precision bearings
that I have found is a vapor degreaser. You boil a solvent (I used
Freon TF back when it was readily available -- or 1,1,1 Trichlor), and
put a double-walled liner at the top which gets cold water run through
it so it condenses the solvent and drips it back into the reservoir.

You could probably do a pretty good job with alcohol -- except
for the risk of igniting the vapors.

[ ... ]

I thought of building a little vapor degreaser as described above that
would use some available but flammable solvent, and running it only in
the middle of the back yard. Someday.

That makes sense.

The plan was to use some vitrified power resistors as the boiler, and a
loop of copper tube soldered to the rim with garden-hose water flowing
through as the cooler.


FWIW -- I can testify that silicone oil (supposedly
non-flammable) *will* ignite and burn if the vapors from a heated beaker
of it curl around into the still-hot elements of the hotplate on which
the beaker is sitting. (There was some dry ice in the beaker to hasten
it back to the starting point of a temperature coeficient run.) And,
when that vapor burns, the result is very fine sand all over the place. :-)

I'll have to try this someday. In the backyard.


In the meantime, I soaked it in WD-40 plus acetone, spinning the bearing
while immersed in solvent, and blew the bearing off with compressed air.

O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

How so?


Hmm ... use a feeler gauge to measure the gap, and cut a piece
of shim stock to serve as a spacer, so you can tighten it firmly without
crushing the bearings.

The lip isn't very deep. Perhaps a piece of copper wire will suffice.

Perhaps.

Or, perhaps I can press the bearing race into place.

That would be better if possible. Can you turn up a cylindrical
pusher to press only on the inner race?

Not yet, but soon. There is a cylindrical sleeve already there. I
think it is supposed to rest on the bearing inner race on one end, and
one flange of the two that hold external grinding wheels on the other.


For the record, both spindle bearing caps are right-hand threaded. I
used the tips of a pair of needle-node pliers as a spanner wrench. The
caps turned easily. I did see some faint marks left by a pipe wrench
on the caps. Anyway, disassembly and reassembly were easy.

O.K. I've got some hinged pin spanners (which I use for the hub
on my surface grinder) which should work well on it, if I need to get
into it.

I would just have at it, and use the opportunity to clean the crud out
of the bearings. It isn't all that tricky or hard; I've had zero
trouble.

O.K. -- Other than getting things fully back together with the
caps fully tightened. (Which I gather was a pre-existing condition. :-)
Perhaps there is some grit stuck between the inner race and the spindle?

Yes, it was pre-existing, and I bet it was that way when Grandfather got
the unit. There is lots of dirt in the way at present.


Mine has an unthreaded nose with axial hole and grub screw.

Hmm ... "grub screw"? You're posting from the UK? I think that
is mostly a UK term. :-)

Well, the Boston area, but a Boston accent (which I don't have but my
wife does have) is really a form of London Cockney.

O.K. I guess that you picked up the term from the net, then.

FWIW My wife is from the area too -- Salem.

I did pick the term up from RCM. Sounds better than setscrew,


From the current Dumore catalog, they had an assortment of spindles,
and the user was expected to change spindles as needed. So, there will be
many kinds of spindle floating around, but they should all fit the
grinder.

Except that those had the entire spindle cartridge removable
from the frame, I believe. If you can't get the bearings off the
spindle, and can't get the spindle out of the cylindrical part of the
housing, then you can't change spindles, I believe.

Yes, but I think that these spindles are removable, as described above.

O.K. But the other fellow who has jumped into the thread has a
spindle like mine, and has screw-on collet adaptors -- not replaceable
spindles.

I wonder. I think that all Series 11 grinders have removable spindles.


FWIW -- my complete model number is 11-011.

Mine is Type 11G, No 1059, 115 Volts. All other info blocks on the tag
are blank. Probably bought for the US Army to a govt spec, and later
sold as surplus to my Grandfather.

O.K. The OD drop-front cabinet suggests that you are right.

[ ... ]

While I don't have good woods for the task -- just whatever is
used to make cheap 2x4s these days -- a bit too soft, I think.

The local Home Despot carries Oak, which is what I used. Oak flooring
cutoffs are often available. Likewise, Maple.

O.K. Maple I would save for use repairing concertinas, not for
one-off tools.

Well, lots of special-purpose tools were made of maple, and it isn't all
that more costly than oak in small quantities at HD, and the grain is
very fine and uniform.

I had to go to a specialty wood shop to get my maple -- of
appropriate thickness for making replacement concertina pieces.

Ouch. I bet it is *very* good wood. There must be other sources.


Big vice, big hammer -- tools to live by.

Well ... not too big a vise in this case. It is a drill-press
vice from Craftsman from about 1970 or so. One with the ability to
mount it at an angle to the surface. Mostly, it had a big enough jaw
opening (barely), it was heavy enough for my task, and it was easy to
get to at the moment. :-)

I'm not impressed. Real vices weigh 100# min. Like anvils.

Agreed. Closer is the original Bridgeport vise which I have. I
*think* that is heavier than the import bench vise which is on one of
the workbenches.

That's more like it....


I wondered about the pulleys, because current grinders from Dumore show
more than two sizes.

Right - they do.

What speeds are quoted on your grinder? Mine says nothing.

Motor first:

15,500 RPM no load
8,000 RPM full load.

This sounds plausible, from the sound while it spins.

You don't have a strobotac? I've recently discovered that they
are on eBay for fairly reasonable prices -- except that I already got
mine at a hamfest.

Thought of it, haven't done it yet.


Pulleys
Wheel size RPM Spindle Motor
=====================================
1/8" to 3/4" 30,000 #1 #2
2" 6,900 #2 #1

My pulleys are 2.165" and 0.906" in diameter, so the available ratios
are 2.39:1 and 0.418:1, for loaded speeds of 19,117 rpm and 3,348 rpm
respectively. No-load speeds are about twice that.

Hmm ... I don't have the measurement for the larger pulley, but
the smaller one has a maximum diameter of 0.9245" -- measured to make
that ring spanner wrench.

I rechecked the diameters, this time with a micrometer (not a caliper).
They are 0.906" and 2.184" in diameter, more or less as reported.


Set it up like surgery, with a sheet of plastic covering everything
except what absolutely must poke through?

Reasonable. I've read suggestions for covering everything with
several layers of wet newspaper, so the abrasive will stick to the
newspaper.

Wet newspaper will rust things, but I suppose that's not as bad as
abrasive grit everywhere.

It will rust things *if*:

1) The surfaces are not first wiped down with Vactra No. 2.

2) The wet newspapers are left on for longer than a work day.

Newsprint is somewhat acid. That's why it yellows so fast.

Vactra #2 seems to be the universal elixer of machine tools.


And -- of course -- the newspapers could be wet down with oil
instead of water. It would accomplish the same purpose, not risk rust,
and make the newspaper harder to dispose of. :-)

With the plastic covering, the classic trick is to use sheet
polyethylene at least 0.002" thick, and force the sheet down on whatever
must penetrate, allowing the punctured sheet to pull tight around
whatever sticks through it.

Reasonable.

[ ... ]

Nice work. One trick to get that kind of precision is to set
the compound at 5.7106 degrees (as close as you can get, at least), and
for every 0.001" you crank the compound feed, you move 0.0001" closer
to the axis. (If you care, that decimal degrees comes out to be:

5 degrees, 42 minutes, 38 seconds

Good luck on the typical compound angle scale. :-)

It's a nice trick, even if one cannot set this on the angle scale. I
would just set it to something, measure the effect of advancing by a
set amount, and then use a hand calculator to figure out what to do to
achieve a specified effect.

Actually -- setting it to 5-3/4 degrees by eye should get you
close enough. You are only going to be making very small reductions in
diameter, so frequent checking with a good micrometer should suffice in
addition to this. This simply lets you make adjustments in finer steps,
and it would be useless for turning, as there is often more spring than
that in even a good rigid lathe.

Right. This only works for grinding on anything other than a Hardinge.

Agreed. Though it works *sometimes* with really sharp cutters
and non work-hardening workpiece materials on the Clausing. When I want
to work to precise dimensions, I often use one of the carbide insert
tools from my Emco-Maier Compact-5/CNC. It is a very small 55 degree
diamond insert, and I lucked into a batch of inserts which are very
sharp and not TiN coated, so the edges are not rounded off. Certainly
the inserts which came with the lathe were not so sharp.

Would HSS, well-sharpened, be better?


My recollection is that it was the 1957 model year Corvette, but I have
not found any documents.

O.K. That was pretty close to the start of the Corvette line,
wasn't it? And the same for the Ford Thunderbird line, for that matter.

I don't recall.

I believe that the two-seat Thunderbird started in 1956. I was
in high school then, in a small town in South Texas, and someone there
got one -- and was the focus of attention. Not too much later, 1959 I
think, Ford spoiled the T-bird by turning it into a four-seater. At
least the Vette remained two-seat all the way into the present.

OK. You are a few years ahead of me.


It turns out that the bread and butter was fuel injection systems for
general aviation engines.

O.K. So this was not just your grandfather, but the company for
which he worked?

Both. I don't think that Grandfather was an employee, as all his
patents were his, and were not assigned to anybody.

O.K. Which explains why he had a shop at home, and could (and
did) do such precision work -- for the prototypes, so he was not
obligated to anyone else, and could license his patents to who he
wished.

Sounds right. Wonder what became of his lathe et al. I didn't inherit
any of it. Though I don't recall his basement being crowded with
machine tools. He must have had a machine shop or at least access
somewhere else.


Too much more to do tonight. Well ... I just took a look at it,
and was reminded how difficult I've found it to follow patent
descriptions of almost anything -- including electronic circuits for
which *I* hold the patent. :-)

I certainly agree, but I've found the patent literature to be quite
useful over the years.

I bet there is a patent covering the Dumore grinder. Are there any
patent numbers on anything? My unit has nothing, but then again it's
pretty spartan.

Hmm The only data source which I have is the motor label, and
all it says on the subject is "Trade Mark Reg US Pat Off" in the upper
left and right corners. :-)

Protects only the trademark "Dumore".


Hmm ... I really think that you still want spindle oils for
this, not motor oils.

Hmm. I wonder what Dumore says about this. This spindle is pretty
fast, but then again this isn't a lathe headstock bearing either.

Another poster said that the carpet thread is original.

He also says that they told how much oil and what grade (which
they specified as their own brand, of course. And the oil is supposed
to only be added at the center.

Yes, Dumore type 0 oil, which sounds to be pretty low viscosity.

I wonder if one can buy new wicks.


I think that oil is wicked to the taper, and propelled towards
increasing diameters by centrifugal force, leading the oil to circulate
through the bearings enough to keep them lubricated. This will work
far above the speed at which splash lubrication fails.

Did you figure out what the central oil port does? Perhaps it
provides a reservoir to replenish the oil from the wicks, and you are
only expected to remove the caps at the ends to replace the wicks?

That's my impression, although the covers over the two wicks are stamped
"oil".

Hmm ... I don't remember any such markings on mine -- just the
screw-in caps with no markings. I at first expected them to allow me to
slide the end caps out when I loosened them. When that didn't happen, I
unscrewed one to find the wick. :-)

[ ... ]

Been there, done that. Cameras are like that too, although physical
bruises are uncommon.

Yes -- the springs are not nearly as strong. :-) I've worked on
them, too.

Did the MGA manual mention how to reassembly this little beauty?

Sure -- the same way they had to reassemble *any* part. The
last paragraph of each section would read:

"Reassembly is a reversal of the above."

Unh.


It was possible to use a chunk of round steel stock (even an old bolt)
to press the bearings and springs in enough to get the rods started,
after which things were fine until you removed the rods again. :-)

I recall working on the front shocks for a MGB my then girlfriend owned.
These were the swing-arm shocks. I don't recall much about them except
that they were a bitch to install without damage to all concerned.

Hmm ... I replaced the ones on my second MGA (1600 Mk II), and I
don't remember it being particularly difficult -- unlike some other
things, including replacing the clutch plate and pressure plate. :-) For
*that*, you have to remove the engine and transmission as a unit. And
to do that as indicated by the manual, you have to remove the
transmission tunnel, and to remove *that* you first had to remove the
floorboards -- plywood floorboards secured by screws which stuck out far
enough through the floor to get dinged and rusted.

After doing it by the book *once*, I figured out how to remove
the motor and transmission without removing the trans tunnel. But it
required small hands and blind dexterity. (It still beat doing it as
intended. :-)

Sadly, I never had the pleasure. GF got rid of that card first. Or
crushed it; don't recall which. Saved by the bell in any case.

Joe Gwinn

"DoN. Nichols" wrote in message
...
According to Glenn :

"DoN. Nichols" wrote in message
...
According to Joseph Gwinn :

SNIP
FWIW -- my complete model number is 11-011.

[ ... ]

Don,
I have the same TPG as yours. Same model number anyway. Mine is in a
Dark
Grey box with just the top opening lid..no drop front.

Instead of the hammertone blue box which I have. I don't know
whether that makes yours or mine older. :-)

My best guess is mine is from 1956

I have the
collett
adapter and the manual that came with it if you need any info from that I
would be happy to scan/measure or whatever.

Both would be lovely to have. I presume that the collet adaptor
screws over the arbor for the plain wheels? I was just about to try
making one from scratch -- after dealing with the income tax torture,
which we just started. :-)

The major problem is that I can't receive e-mails larger than
30K -- as a means of keeping viruses out of some mailing lists which I
run.

An FTP site, or a web site would help. Perhaps you could
upload them to the dropbox (http://www.metalworking.com), and I could
pick them up from there? That would allow others to benefit from them
as well.

If you would prefer to not do that -- could you burn a CD-ROM of
the scans and snail-mail it? (There should be plenty of room on a
CD-ROM for everything needed and then some -- even if you scan for
output to a 600 DPI printer. :-) The manual for my Clausing lathe,
scanned to TIF for such a printer, converted to PostScript, and from
there to PDF results in a total file size of 6,964,511 -- about 1/100th
of a CD-ROM. :-)

If it works for you I will just scan it to PDF and post it to the drop box.
The manual is only 6, 8.5X11" pages.
I think this is at least as on topic as a leaky bush

FWIW the Lubrication instructions say to use 25 to 50 drops of Dumore No
0
High speed oil every 10 hours of operation. The oil is added to the Gits
snap cap oiler located in front of the tool post. The 2 screws on the
ends
of the spindle housing are for the oil wicks and they do have a thread
wraped around the felt to ride on the spindle tapers. Inside is a felt
cylinder that is called the oil retainer.

O.K. "No. 0 High speed oil" sounds like a very thin spindle oil
to me, so what I got for my surface grinder would be about right.

I use #10 turbine oil in mine and it seems happy with it.

The collett adapter is a threaded sleeve type thing that has the collett
chuck on one end and is threaded internally to screw onto the spindle.
Looks a lot like somebody cut the end off a dremel only a bit larger OD
on
the shaft. It is counter bored so it threads up to the sholder on the
spindle.

That sounds like what I was planning to make. What is the
overall length to the end of the collet? (This will give me a target to
shoot for.)

Ok .. Let's see if I can make a picture with words
The collett adapter is only 2 pieces. The main body is 1.685" OAL and .427"
OD. The large part of the body is 1.125" long and is drilled and tapped to
match the shaft extension. The collet portion is threaded for 5/16 32 for
..325" and drilled for .125" shaft then split 4 ways. The last .130" is
tapered to provide the clamping from the collett closer nut. There are 2
flats on the shaft and on the nut for collett wrenches and the nut is
knurled also.It looks like they tapped the internal threads first and then
bored out the ID to fit the unthreaded part of the spindle. The 1/8" hole
goes all the way into the 1/4" hole. My spindle is threaded for 1/4 32 BTW.
I think it is easier to make one then to describe it

If any more info would help let me know. I think the only thing mine
dosen't have is the scatter guard for the OD wheels. The parts list
dosen't
show one but some of the ictures do.

Since I don't have the manual, I don't have the parts list
either. But I saw guards in some of the photos on the DuMore web site
when I tried to find information and really did not feel like spinning
up a larger wheel without one, so I made one to fit. (Turned from some
3-1/2" diameter aluminum. You probably visited the quick-and-dirty web
page and saw one shot of it, at least. If you want, I can send the
dimensions which I worked to as a drawing.

I did go to your Q&D and I think I can make a good facsimile of your scatter
guard. Thanks for the idea.

BTW -- My e-mail address is valid, if you want to take this
off line -- though we've got at least one other in the thread
who can benefit from what you know as well.

I don't know much but I did get lucky and get the manual with my TPG I
think the exploded parts diagram will tell you more than anything else in
the book.

Glenn

"DoN. Nichols" wrote in message
...
According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:
Or, perhaps I can press the bearing race into place.

That would be better if possible. Can you turn up a cylindrical
pusher to press only on the inner race?

Not yet, but soon. There is a cylindrical sleeve already there. I
think it is supposed to rest on the bearing inner race on one end, and
one flange of the two that hold external grinding wheels on the other.

The manual with exploded parts diagram is now in the drop box. I scaned at
150 DPI enhanced text mode to keep it small so the B&W photos are not all
that wonderful. The text and parts list is easily readable though. I added
a scan of the collett adapter with the dimensions roughed in. Should give
you all you need to make a servicable piece.
I think the exploded diagram will answer a lot of questions about how the
spindle and bearings go together.

I would just have at it, and use the opportunity to clean the crud
out
of the bearings. It isn't all that tricky or hard; I've had zero
trouble.

O.K. -- Other than getting things fully back together with the
caps fully tightened. (Which I gather was a pre-existing condition. :-)
Perhaps there is some grit stuck between the inner race and the
spindle?

Yes, it was pre-existing, and I bet it was that way when Grandfather got
the unit. There is lots of dirt in the way at present.

O.K. You get yours back together properly, and then I will take
mine apart -- assuming that the manual does not turn out to say *don't*
in big bold letters. :-)

I think this manual was written before the lawsuit happy lawyers got
involved .. there really aren't many of the "warnings" you see in modern
manuals. Interestingly enough it does say to use only Dumore precision
balanced grinding wheels LOL

Not to hijack your converstion about MGs but I had a 69' MGB while I was
stationed in Germany in the early 70s'. A real kick in the pants over
there. It had the lever action shocks that you could top up with oil and
mine were getting a bit soft so I added some STP and it siffend it right up
I have a 63' Corvette that is a "project in waiting". I retire soon ..
may be retired now and don't know it yet And then the vette goes under
the microscope to be our fun car. I have an 87 Porsche that is my daily
driver and weekend toy but it just dosen't have the character of the MG or
the Vette Unfortunately the Vette is not a fuelie though I think they
were using a bosche injection system by the 60's.

Anyway if there is anything else you need for info or pictures let me know.

Glenn

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]


FWIW -- I can testify that silicone oil (supposedly
non-flammable) *will* ignite and burn if the vapors from a heated beaker
of it curl around into the still-hot elements of the hotplate on which
the beaker is sitting. (There was some dry ice in the beaker to hasten
it back to the starting point of a temperature coefficient run.) And,
when that vapor burns, the result is very fine sand all over the place.
:-)

I'll have to try this someday. In the backyard.

Be sure to have a CO2 fire extinguisher handy. I'm not sure
what a hose would do for that -- possibly float and spread the burning
silicone oil.

Note that this was a mix of two silicone oils -- one which was
normally used for measurement at -50C, and the other which was normally
used at +150C. The first would boil at the high temperature, and the
second would set up into a grease at the low end, making it hard to
equate the temperature at the thermometer with that in the device under
test. The low-temperature oil, when it hit the bubbles from the dry ice
in the beaker evaporated quickly, and spilled over the edge and curled
into the heating elements.

We would have been better off letting the beaker cool down on
its own -- but we had quite a few more devices to test -- ones returned
from the customer, because while they met specs at -50, +50, and +150C,
they were out of spec at some points between those temperatures.

Ahh. I have a hotplate with totally enclosed heaters, so no drama is
likely.


In the meantime, I soaked it in WD-40 plus acetone, spinning the bearing
while immersed in solvent, and blew the bearing off with compressed
air.

O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

How so?

It can spin up to a fast enough RPM so the centrifugal force (I
know -- there really is no such thing) will cause it to fly apart --
turning it into shrapnel -- and *you* into a target. I don't know
whether there is any size limit for this to happen, but it has been
known to happen and to harm or kill people nearby.

Ahh. I can see a large bearing being driven fast enough to explode,
especially as bearing races are designed to be reinforced by being
pressed into a recess in a larger housing.

However, One would think that overspeed isn't going to be an issue with
small bearings already specified for 30,000 rpm, unless one's air supply
is something else.


Or, perhaps I can press the bearing race into place.

That would be better if possible. Can you turn up a cylindrical
pusher to press only on the inner race?

Not yet, but soon. There is a cylindrical sleeve already there. I
think it is supposed to rest on the bearing inner race on one end, and
one flange of the two that hold external grinding wheels on the other.

O.K.

It strikes me that one may be able to use the flange nut to push the
race back into position.


I would just have at it, and use the opportunity to clean the crud out
of the bearings. It isn't all that tricky or hard; I've had zero
trouble.

O.K. -- Other than getting things fully back together with the
caps fully tightened. (Which I gather was a pre-existing condition. :-)
Perhaps there is some grit stuck between the inner race and the spindle?

Yes, it was pre-existing, and I bet it was that way when Grandfather got
the unit. There is lots of dirt in the way at present.

O.K. You get yours back together properly, and then I will take
mine apart -- assuming that the manual does not turn out to say *don't*
in big bold letters. :-)

It's all back together. I will have to take it apart to push the one
bearing race back into place.


O.K. But the other fellow who has jumped into the thread has a
spindle like mine, and has screw-on collet adaptors -- not replaceable
spindles.

I wonder. I think that all Series 11 grinders have removable spindles.

It may depend on what you call "removable". Certainly the ones
which started this thread were designed to screw into a hollow spindle
with a taper, based on the photos. (Hmm ... has that auction closed,
yet? :-)

I think that the hollow spindle is a later design.



15,500 RPM no load
8,000 RPM full load.

This sounds plausible, from the sound while it spins.

You don't have a strobotac? I've recently discovered that they
are on eBay for fairly reasonable prices -- except that I already got
mine at a hamfest.

Thought of it, haven't done it yet.

O.K. If you can -- try to pick up on another auction of FX-6A
flashlamps -- these darken with use, and are now *very* hard to find. I
finally won an auction for enough to keep me going for a while.

Lots of flashlamps are made, and such things are not very critical. Is
there something else that will work?

Hmm. That number rings a bell. FX-6A is an old EG&G product. The
relevant part of EG&G was sold to Perkin-Elmer
(http://optoelectronics.perkinelmer.com), but still makes flashlamps.

The FX-6A is still available:

http://opto.mondosearch.com/cgi-bin/...ge_id=1153&que
ry=FX6a&hiword=FX6a%20

No idea what they cost, but they won't be cheap.

Selected General Radio stuff is now made by IET Labs www.ietlabs.com,
and they list flashlamps for $200 to $300, which I bet is more than old
Strobotacs go for on ebay.

For ~$300, one can buy a new Extech strobe/tach:
Vhttp://www.extech.com/instrument/products/451_499/461831_461830.html.
However, this unit goes only to 10,000 flashes per minute, insufficient
for a grinder spindle.


I bet there is a patent covering the Dumore grinder. Are there any
patent numbers on anything? My unit has nothing, but then again it's
pretty spartan.

Hmm The only data source which I have is the motor label, and
all it says on the subject is "Trade Mark Reg US Pat Off" in the upper
left and right corners. :-)

Protects only the trademark "Dumore".

Yep -- but that is all the information that I have from my
grinder. And I wonder how much of it would be patentable by that time.
Perhaps not enough to make it worth while hanging patent numbers on it,
if the patents were all expired.

Companies vary in this.


He also says that they told how much oil and what grade (which
they specified as their own brand, of course. And the oil is supposed
to only be added at the center.

Yes, Dumore type 0 oil, which sounds to be pretty low viscosity.

I wonder if one can buy new wicks.

I suspect that one would need to make new wicks at this point.
You can get appropriate felt from McMaster Carr for the task.

True, but if I order the spindle oil, might as well get some pre-made
wicks. My unit did not come with a belt, and I ordered that some years
ago, just so I could try it out. At the time, I didn't really know what
a toolpost grinder was for. Grinding tool posts?


Joe Gwinn

According to Glenn :

"DoN. Nichols" wrote in message

[ ... ]

Not yet, but soon. There is a cylindrical sleeve already there. I
think it is supposed to rest on the bearing inner race on one end, and
one flange of the two that hold external grinding wheels on the other.

The manual with exploded parts diagram is now in the drop box. I scaned at
150 DPI enhanced text mode to keep it small so the B&W photos are not all
that wonderful.

Yep -- the photos are terrible (other than your direct scan of
the collet). -- but I think that I can make out what they are about.
These tradeoffs are necessary when file size is important.

The text and parts list is easily readable though. I added
a scan of the collett adapter with the dimensions roughed in. Should give
you all you need to make a servicable piece.

I believe that it will do for the task.

Thank you for this.

I think the exploded diagram will answer a lot of questions about how the
spindle and bearings go together.

Indeed so.

I would just have at it, and use the opportunity to clean the crud
out
of the bearings. It isn't all that tricky or hard; I've had zero
trouble.

O.K. -- Other than getting things fully back together with the
caps fully tightened. (Which I gather was a pre-existing condition. :-)
Perhaps there is some grit stuck between the inner race and the
spindle?

Yes, it was pre-existing, and I bet it was that way when Grandfather got
the unit. There is lots of dirt in the way at present.

O.K. You get yours back together properly, and then I will take
mine apart -- assuming that the manual does not turn out to say *don't*
in big bold letters. :-)

I think this manual was written before the lawsuit happy lawyers got
involved .. there really aren't many of the "warnings" you see in modern
manuals. Interestingly enough it does say to use only Dumore precision
balanced grinding wheels LOL

And also on page 2 is the all upper case:

"WARNING: DO NOT EXCEED WHEEL SPEED RECOMMENDATIONS."

(But no exclamation point at the end. :-)

The manual is obviously older than my grinder, because of the
lack of 3-pin power connectors. But it is obviously for the same
grinder, as the model number (first four digits of the serial number)
matches.

Not to hijack your converstion about MGs but I had a 69' MGB while I was
stationed in Germany in the early 70s'. A real kick in the pants over
there. It had the lever action shocks that you could top up with oil and
mine were getting a bit soft so I added some STP and it siffend it right up


That was a common treatment for autocross (gymkana)
competitions, where cornering was at a premium.

My shocks were leaking, and I was topping them up with Silicone
oil (Dow Corning No. 200, IIRC) until I got a replacement set from a
crashed MGA at the junkyard. They looked so nice that I figured that
they had just been installed, and he took it out for too much of a
high-speed trial, and lost it. None of the accumulated grunge which
were on the original shocks.

My car which followed the MGA was a BMW 2002. Now it is
something unimaginative -- a Mazda 3/4 ton pickup truck with 4WD to deal
with our snow and our steep driveway. :-)

I have a 63' Corvette that is a "project in waiting". I retire soon ..
may be retired now and don't know it yet And then the vette goes under
the microscope to be our fun car. I have an 87 Porsche that is my daily
driver and weekend toy but it just dosen't have the character of the MG or
the Vette Unfortunately the Vette is not a fuelie though I think they
were using a bosche injection system by the 60's.

Hmm ... I remember a friend who had a Vette (about 1970, IIRC)
just before the first fuel crisis here -- he said that it would pass
anything but a fuel station -- he sold it just in time. :-)

Anyway if there is anything else you need for info or pictures let me know.

I think that those will do the job for me. I already have them
printed out -- and the photos did not improve in the process. :-)

The added info in the .txt file will help as well. I am glad to
get confirmation that the spindle thread was originally 1/4-32.

Was there only the one "Chuck assembly" with a 1/8" bore? That
would appear to be the case, based on the parts list and drawing.

So -- the largest wheel really was a 2" one. I've got some
larger ones which I have adapted to the spindle which are still well
within their speed rating -- but perhaps the motor does not have the
horsepower to drive the larger wheels. I guess that I'll find out.

The design of the diamond holder is different than I had
expected -- but makes sense if you have to re-dress the wheel part-way
through the task.

I don't see the diamond holder listed in the parts list, nor in
the drawing.

Again -- many thanks,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

FWIW -- I can testify that silicone oil (supposedly
non-flammable) *will* ignite and burn if the vapors from a heated beaker

[ ... ]

I'll have to try this someday. In the backyard.

Be sure to have a CO2 fire extinguisher handy. I'm not sure
what a hose would do for that -- possibly float and spread the burning
silicone oil.

[ ... ]

We would have been better off letting the beaker cool down on
its own -- but we had quite a few more devices to test -- ones returned
from the customer, because while they met specs at -50, +50, and +150C,
they were out of spec at some points between those temperatures.

Ahh. I have a hotplate with totally enclosed heaters, so no drama is
likely.

The elements were not visible, but were under the plate's top,
so the curling vapors reached them underneath.

[ ... ]

O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

How so?

It can spin up to a fast enough RPM so the centrifugal force (I
know -- there really is no such thing) will cause it to fly apart --
turning it into shrapnel -- and *you* into a target. I don't know
whether there is any size limit for this to happen, but it has been
known to happen and to harm or kill people nearby.

Ahh. I can see a large bearing being driven fast enough to explode,
especially as bearing races are designed to be reinforced by being
pressed into a recess in a larger housing.

However, One would think that overspeed isn't going to be an issue with
small bearings already specified for 30,000 rpm, unless one's air supply
is something else.

I think that it may be a function of the size of the air exit in
the nozzle vs the air pressure. But also -- depending on where you hit
the bearings, you can get speed multiplication -- probably the worst is
driving at the balls themselves, which could easily double the air
speed.


Or, perhaps I can press the bearing race into place.

That would be better if possible. Can you turn up a cylindrical
pusher to press only on the inner race?

Not yet, but soon. There is a cylindrical sleeve already there. I
think it is supposed to rest on the bearing inner race on one end, and
one flange of the two that hold external grinding wheels on the other.

O.K.

It strikes me that one may be able to use the flange nut to push the
race back into position.

Quite likely so.

[ ... ]

O.K. You get yours back together properly, and then I will take
mine apart -- assuming that the manual does not turn out to say *don't*
in big bold letters. :-)

It's all back together. I will have to take it apart to push the one
bearing race back into place.

O.K. At least the manual (I presume that you downloaded it as
well) does not say to not disassemble it.

Interesting that there are different numbers (and different part
numbers) for the motor bearings depending on which end, but the spindle
bearings have the same number at each end.


O.K. But the other fellow who has jumped into the thread has a
spindle like mine, and has screw-on collet adaptors -- not replaceable
spindles.

I wonder. I think that all Series 11 grinders have removable spindles.

It may depend on what you call "removable". Certainly the ones
which started this thread were designed to screw into a hollow spindle
with a taper, based on the photos. (Hmm ... has that auction closed,
yet? :-)

I think that the hollow spindle is a later design.

O.K. But the manual does show that for this model at least, the
same spindle is used for both larger wheels and smaller mounted ones --
with a screw-on single-sized collet adaptor.

[ ... ]

O.K. If you can -- try to pick up on another auction of FX-6A
flashlamps -- these darken with use, and are now *very* hard to find. I
finally won an auction for enough to keep me going for a while.

Lots of flashlamps are made, and such things are not very critical. Is
there something else that will work?

I suspect not. It has several unique features:

1) It is in a stubby 9-pin miniature tube housing.

2) aside from the two heavy-duty flash electrodes at perhaps
a 1/2" spacing, there are five internal trigger wires set up to
produce a ionized track between the two electrodes. They look
something like this from a top (end) view:

(View with a fixed pitch font like courier to avoid distortion.)


__ -----__
-- --
/ \
/ \
/ \
| | | | |
| ##### | | | ##### |
| ##### | | ##### |
| | | |
\ /
\ /
\ /
--__ __--
-----

Sorry -- it is difficult to make a nice circle using ASCII graphics. :-)

the '#'s make up the electrode blocks, while the '|'s are the trigger
wires -- each going to a different pin on the base. The flash
electrodes are connected to pins 1 and 6 (if I remember the direction of
pin counting on those base), The two bottom ones (as drawn above) are
connected to pins 3 and 4, and the three top ones are connected to pins
7, 8, and 9.

I think that it would be difficult to adapt the typical
flashlamp to the purpose. And the diameter and base of the lamp are
needed, as it plugs into a socket on the end of the stub, and the flash
reflector slides on over the lamp once it is plugged in.

Hmm. That number rings a bell. FX-6A is an old EG&G product.

Yep. A friend got one at Eli's surplus at MIT, and got a data
sheet from Dr. Edgerton. He asked what we got it for, and then told us
that he wished that *he* could get them at that price. The new price
was $15.00 in 1960, IIRC. No doubt, it has not gone down since then. :-)

The
relevant part of EG&G was sold to Perkin-Elmer
(http://optoelectronics.perkinelmer.com), but still makes flashlamps.

The FX-6A is still available:

http://opto.mondosearch.com/cgi-bin/...ge_id=1153&que
ry=FX6a&hiword=FX6a%20

Good!

No idea what they cost, but they won't be cheap.

No bets on that. :-)

Selected General Radio stuff is now made by IET Labs www.ietlabs.com,
and they list flashlamps for $200 to $300, which I bet is more than old
Strobotacs go for on ebay.

It is about an order or magnitude more. I got a set of about
five or six FX-6A lamps from an ebay auction for a fairly reasonable
price, after losing an auction for a similar number which went into the
stratosphere -- at least based on what I was willing to pay. :-)

For ~$300, one can buy a new Extech strobe/tach:
Vhttp://www.extech.com/instrument/products/451_499/461831_461830.html.
However, this unit goes only to 10,000 flashes per minute, insufficient
for a grinder spindle.

Yep. My Strobotac goes up to 25K Flashes Per Minute. It is a
model 1531-A, FWIW. The older one with the dark gray crackle panel
finish, not the later one with the light gray smooth finish.

[ ... ]

He also says that they told how much oil and what grade (which
they specified as their own brand, of course. And the oil is supposed
to only be added at the center.

Yes, Dumore type 0 oil, which sounds to be pretty low viscosity.

I wonder if one can buy new wicks.

I suspect that one would need to make new wicks at this point.
You can get appropriate felt from McMaster Carr for the task.

True, but if I order the spindle oil, might as well get some pre-made
wicks. My unit did not come with a belt, and I ordered that some years
ago, just so I could try it out. At the time, I didn't really know what
a toolpost grinder was for. Grinding tool posts?

O.K. Some years ago I got a Dumore drill grinder, and got a
manual from them at that time. A couple of years later, I got the
toolpost grinder, and a phone call had them not having any manuals or
parts for toolpost grinders that old.

If you haven't already, download the manual and the .txt page
posted to the dropbox (http://www.metalworking.com). The files are
under the names:

Dumore_Series_11_TPG.pdf

Dumore_Series_11_TPG_Manual.txt

The .txt normally just explains what is in the image or .pdf files, but
in this case, it also gives some additional dimensions for the collet
holder which Dumore called the "chuck".

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

According to Glenn :

"DoN. Nichols" wrote in message
...
According to Glenn :

[ ... ]

I have the same TPG as yours. Same model number anyway. Mine is in a
Dark
Grey box with just the top opening lid..no drop front.

Instead of the hammertone blue box which I have. I don't know
whether that makes yours or mine older. :-)

My best guess is mine is from 1956

O.K. That might put mine as 1960 or so.

Does yours have the separate ground wire and connector as shown
in the manual? I would expect that a 1956 one might have already moved
to the standard 3-pin power plug such as mine has.

[ ... ]

If it works for you I will just scan it to PDF and post it to the drop box.
The manual is only 6, 8.5X11" pages.

That is what you did -- and I thank you for this. It worked out
quite nicely -- and I suspect will help the other participant in this
thread as well.

I think this is at least as on topic as a leaky bush

Far more so, I believe. Rebuilding of metal metalworking tools
is certainly on topic. :-)

[ ... ]

O.K. "No. 0 High speed oil" sounds like a very thin spindle oil
to me, so what I got for my surface grinder would be about right.

I use #10 turbine oil in mine and it seems happy with it.

O.K. That should work nicely. You might even get away with
automatic transmission fluid, which is a nice thin oil.

The collett adapter is a threaded sleeve type thing that has the collett
chuck on one end and is threaded internally to screw onto the spindle.
Looks a lot like somebody cut the end off a dremel only a bit larger OD
on
the shaft. It is counter bored so it threads up to the sholder on the
spindle.

That sounds like what I was planning to make. What is the
overall length to the end of the collet? (This will give me a target to
shoot for.)

Ok .. Let's see if I can make a picture with words
The collett adapter is only 2 pieces. The main body is 1.685" OAL and .427"
OD. The large part of the body is 1.125" long and is drilled and tapped to
match the shaft extension. The collet portion is threaded for 5/16 32 for
.325" and drilled for .125" shaft then split 4 ways. The last .130" is
tapered to provide the clamping from the collett closer nut. There are 2
flats on the shaft and on the nut for collett wrenches and the nut is
knurled also.It looks like they tapped the internal threads first and then
bored out the ID to fit the unthreaded part of the spindle. The 1/8" hole
goes all the way into the 1/4" hole. My spindle is threaded for 1/4 32 BTW.
I think it is easier to make one then to describe it

Thanks -- this adds to the information from the scans and the
..txt file which accompanys them. In particular -- the information about
the 1/8" hole being all the way through to the 1/4-32 threaded section,
and the number of splits in the collet section.

If any more info would help let me know. I think the only thing mine
dosen't have is the scatter guard for the OD wheels. The parts list
dosen't
show one but some of the ictures do.

Since I don't have the manual, I don't have the parts list
either. But I saw guards in some of the photos on the DuMore web site
when I tried to find information and really did not feel like spinning
up a larger wheel without one, so I made one to fit. (Turned from some
3-1/2" diameter aluminum. You probably visited the quick-and-dirty web
page and saw one shot of it, at least. If you want, I can send the
dimensions which I worked to as a drawing.

I did go to your Q&D and I think I can make a good facsimile of your scatter
guard. Thanks for the idea.

Great. FWIW, The bore to slip over the end of the spindle
housing is 1.1125" (+0.001"/-0.0005" should do, I think.) The
thumbscrew was one which I happened to have a box of with a nice smooth
end so it will not dig into the bearing housing. I leave 0.125" of the
end of the bore down at 1.000" to serve as a stop when I slide it on.
The open side was the last thing cut -- with a big wide slab mill on a
horizontal milling machine -- but of course you adapt to whatever
machine tools you have. I opted for thicker at the OD of the guard, to
better control exploding wheels. It was sized for a wheel which is
noticeably larger than the 2" wheel listed in the manual as the largest,
but that wheel still has a maximum speed well above the speed of the
spindle -- so it remains to be seen whether the motor can drive the
extra diameter. If not, then perhaps I go into making extra pulleys (a
#0 and a #3 perhaps) to extend the speed range a bit.

BTW -- My e-mail address is valid, if you want to take this
off line -- though we've got at least one other in the thread
who can benefit from what you know as well.

I don't know much but I did get lucky and get the manual with my TPG I
think the exploded parts diagram will tell you more than anything else in
the book.

It does indeed. It confirms a lot of what I had already
believed, and your measurements confirm other things.

Thanks again,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

FWIW -- I can testify that silicone oil (supposedly
non-flammable) *will* ignite and burn if the vapors from a heated
beaker

We would have been better off letting the beaker cool down on
its own -- but we had quite a few more devices to test -- ones returned
from the customer, because while they met specs at -50, +50, and +150C,
they were out of spec at some points between those temperatures.

Ahh. I have a hotplate with totally enclosed heaters, so no drama is
likely.

The elements were not visible, but were under the plate's top,
so the curling vapors reached them underneath.

Ah. Needs an iron skirt.


O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

How so?

It can spin up to a fast enough RPM so the centrifugal force (I
know -- there really is no such thing) will cause it to fly apart --
turning it into shrapnel -- and *you* into a target. I don't know
whether there is any size limit for this to happen, but it has been
known to happen and to harm or kill people nearby.

Ahh. I can see a large bearing being driven fast enough to explode,
especially as bearing races are designed to be reinforced by being
pressed into a recess in a larger housing.

However, One would think that overspeed isn't going to be an issue with
small bearings already specified for 30,000 rpm, unless one's air supply
is something else.

I think that it may be a function of the size of the air exit in
the nozzle vs the air pressure. But also -- depending on where you hit
the bearings, you can get speed multiplication -- probably the worst is
driving at the balls themselves, which could easily double the air
speed.

I'll have to think about this. One can compute the airstream velocity
at the output side of the orifice of the blowoff nozzle, and use this to
computer rpm. It would be hard for the airstream to get a purchase on
anything other than the balls - everything else is too smooth.



O.K. You get yours back together properly, and then I will take
mine apart -- assuming that the manual does not turn out to say *don't*
in big bold letters. :-)

It's all back together. I will have to take it apart to push the one
bearing race back into place.

O.K. At least the manual (I presume that you downloaded it as
well) does not say to not disassemble it.

I just downloaded the manual. Quite interesting.


Interesting that there are different numbers (and different part
numbers) for the motor bearings depending on which end, but the spindle
bearings have the same number at each end.

They look the same too. The motor has a shaft coming out of one end
only, while the spindle has shafts coming out at both ends.


O.K. But the other fellow who has jumped into the thread has a
spindle like mine, and has screw-on collet adaptors -- not
replaceable
spindles.

I wonder. I think that all Series 11 grinders have removable spindles.

It may depend on what you call "removable". Certainly the ones
which started this thread were designed to screw into a hollow spindle
with a taper, based on the photos. (Hmm ... has that auction closed,
yet? :-)

I think that the hollow spindle is a later design.

O.K. But the manual does show that for this model at least, the
same spindle is used for both larger wheels and smaller mounted ones --
with a screw-on single-sized collet adaptor.

Yes. It appears to be the earlier design. The hollow spindle design
allows one to change the business end without disassembling the grinder.


O.K. If you can -- try to pick up on another auction of FX-6A
flashlamps -- these darken with use, and are now *very* hard to find. I
finally won an auction for enough to keep me going for a while.

Lots of flashlamps are made, and such things are not very critical. Is
there something else that will work?

I suspect not. It has several unique features:

1) It is in a stubby 9-pin miniature tube housing.

2) aside from the two heavy-duty flash electrodes at perhaps
a 1/2" spacing, there are five internal trigger wires set up to
produce a ionized track between the two electrodes. They look
something like this from a top (end) view:

[snip]

Sorry -- it is difficult to make a nice circle using ASCII graphics. :-)

[snip]

I think that it would be difficult to adapt the typical
flashlamp to the purpose. And the diameter and base of the lamp are
needed, as it plugs into a socket on the end of the stub, and the flash
reflector slides on over the lamp once it is plugged in.

One does not have to duplicate these details. An electrical match will
generally work. Basically, one matches the flash voltage range (say 300
volts), the energy capacity (4 Joules/flash, max), trigger voltage (say
6 KV), and trigger energy (say 1 millijoule). (These are not the
correct values for the FX-6A, but give the idea.)


Hmm. That number rings a bell. FX-6A is an old EG&G product.

Yep. A friend got one at Eli's surplus at MIT, and got a data
sheet from Dr. Edgerton. He asked what we got it for, and then told us
that he wished that *he* could get them at that price. The new price
was $15.00 in 1960, IIRC. No doubt, it has not gone down since then. :-)

The relevant part of EG&G was sold to Perkin-Elmer
(http://optoelectronics.perkinelmer.com), but still makes flashlamps.

The FX-6A is still available:

http://opto.mondosearch.com/cgi-bin/...ge_id=1153&que
ry=FX6a&hiword=FX6a%20

Good!

No idea what they cost, but they won't be cheap.

No bets on that. :-)

Selected General Radio stuff is now made by IET Labs www.ietlabs.com,
and they list flashlamps for $200 to $300, which I bet is more than old
Strobotacs go for on ebay.

It is about an order or magnitude more. I got a set of about
five or six FX-6A lamps from an ebay auction for a fairly reasonable
price, after losing an auction for a similar number which went into the
stratosphere -- at least based on what I was willing to pay. :-)

For ~$300, one can buy a new Extech strobe/tach:
http://www.extech.com/instrument/products/451_499/461831_461830.html.
However, this unit goes only to 10,000 flashes per minute, insufficient
for a grinder spindle.

Yep. My Strobotac goes up to 25K Flashes Per Minute. It is a
model 1531-A, FWIW. The older one with the dark gray crackle panel
finish, not the later one with the light gray smooth finish.

Hmm. If the flashtubes aren't too deal, this could be a good idea, even
if the tubes cost more than the unit.


He also says that they told how much oil and what grade (which
they specified as their own brand, of course. And the oil is
supposed to only be added at the center.

Yes, Dumore type 0 oil, which sounds to be pretty low viscosity.

I wonder if one can buy new wicks.

I suspect that one would need to make new wicks at this point.
You can get appropriate felt from McMaster Carr for the task.

True, but if I order the spindle oil, might as well get some pre-made
wicks. My unit did not come with a belt, and I ordered that some years
ago, just so I could try it out. At the time, I didn't really know what
a toolpost grinder was for. Grinding tool posts?

O.K. Some years ago I got a Dumore drill grinder, and got a
manual from them at that time. A couple of years later, I got the
toolpost grinder, and a phone call had them not having any manuals or
parts for toolpost grinders that old.

I can understand ditching the repair parts after 50 years, but how much
trouble would it have been to scan and post the old manuals? These old
units are quite well made, and so will always be with us.


If you haven't already, download the manual and the .txt page
posted to the dropbox (http://www.metalworking.com). The files are
under the names:

Dumore_Series_11_TPG.pdf

Dumore_Series_11_TPG_Manual.txt

The .txt normally just explains what is in the image or .pdf files, but
in this case, it also gives some additional dimensions for the collet
holder which Dumore called the "chuck".

Got them, Thanks. Would have liked the photos to be legible. Perhaps
we can impose on the poster to provide a high-rez scan as well.


Joe Gwinn

O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

How so?

It can spin up to a fast enough RPM so the centrifugal force (I
know -- there really is no such thing) will cause it to fly apart
-- turning it into shrapnel -- and *you* into a target. I don't
know whether there is any size limit for this to happen, but it
has been known to happen and to harm or kill people nearby.

Ahh. I can see a large bearing being driven fast enough to explode,
especially as bearing races are designed to be reinforced by being
pressed into a recess in a larger housing.

However, One would think that overspeed isn't going to be an issue
with small bearings already specified for 30,000 rpm, unless one's
air supply is something else.


Spinnning a bearing with compressed air is a complete NONO!
Firstly this practice will ruin the bearing - think no lubrication.
Dangerous - as has been mentioned the bearing can explode and sometimes the
bearing will seize.
As the handiest workholder is a finger a seizure at high speed will severely
damage said workholder.

Cleaning with air is quite allright - oil the bearing immediately after such
treatment as moisture will be present in the air and/or will condence on the
(now) cold bearing.

Regards.
Ken

--
Volunteer your idle computer time for cancer research
http//www.grid.org/download/gold/download.htm
Return address courtesy of Spammotel http://www.spammotel.com/

On Tue, 11 Apr 2006 11:21:34 -0700, "Ken Davey"
wrote:


O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

How so?

It can spin up to a fast enough RPM so the centrifugal force (I
know -- there really is no such thing) will cause it to fly apart
-- turning it into shrapnel -- and *you* into a target. I don't
know whether there is any size limit for this to happen, but it
has been known to happen and to harm or kill people nearby.

Ahh. I can see a large bearing being driven fast enough to explode,
especially as bearing races are designed to be reinforced by being
pressed into a recess in a larger housing.

However, One would think that overspeed isn't going to be an issue
with small bearings already specified for 30,000 rpm, unless one's
air supply is something else.


Spinnning a bearing with compressed air is a complete NONO!
Firstly this practice will ruin the bearing - think no lubrication.
Dangerous - as has been mentioned the bearing can explode and sometimes the
bearing will seize.
As the handiest workholder is a finger a seizure at high speed will severely
damage said workholder.

Cleaning with air is quite allright - oil the bearing immediately after such
treatment as moisture will be present in the air and/or will condence on the
(now) cold bearing.

Regards.
Ken

--
Volunteer your idle computer time for cancer research
http//www.grid.org/download/gold/download.htm
Return address courtesy of Spammotel http://www.spammotel.com/

Years ago I was blowing out some bearings with air. Goofing off, with
the bearing on my finger, I spun one up and listened to the pitch. As
it spun the pitch got higher until I couldn't hear it. Just as it
passed into my ultrasonic range it exploded with a bang. The bearing
axis was perpendicular to my body so that the bearing parts were
embedded into the wall and not me. My finger hurt like hell. I think
the bearing must have exploded pretty equally because otherwise that
finger would have probably broken instead. I don't spin up bearings
any more. Not even a little.
ERS

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

Ahh. I can see a large bearing being driven fast enough to explode,
especially as bearing races are designed to be reinforced by being
pressed into a recess in a larger housing.

However, One would think that overspeed isn't going to be an issue with
small bearings already specified for 30,000 rpm, unless one's air supply
is something else.

I think that it may be a function of the size of the air exit in
the nozzle vs the air pressure. But also -- depending on where you hit
the bearings, you can get speed multiplication -- probably the worst is
driving at the balls themselves, which could easily double the air
speed.

I'll have to think about this. One can compute the airstream velocity
at the output side of the orifice of the blowoff nozzle, and use this to
computer rpm. It would be hard for the airstream to get a purchase on
anything other than the balls - everything else is too smooth.

As you probably have seen already -- there was a followup posted
which strongly supports my warning.

[ ... ]

O.K. At least the manual (I presume that you downloaded it as
well) does not say to not disassemble it.

I just downloaded the manual. Quite interesting.

Even if it does not precisely cover your version. How do the
model numbers compare? (The first four digits of the serial number).
Mine are an exact match.

Interesting that there are different numbers (and different part
numbers) for the motor bearings depending on which end, but the spindle
bearings have the same number at each end.

They look the same too. The motor has a shaft coming out of one end
only, while the spindle has shafts coming out at both ends.

Right -- but that should not make any difference. Perhaps the
difference in the motor bearings is because only the pulley end of the
motor experiences side loads, while both ends of the spindle do.

Or -- the bearings *may* be identical. :-)

[ ... ]

It may depend on what you call "removable". Certainly the ones
which started this thread were designed to screw into a hollow spindle
with a taper, based on the photos. (Hmm ... has that auction closed,
yet? :-)

I think that the hollow spindle is a later design.

O.K. But the manual does show that for this model at least, the
same spindle is used for both larger wheels and smaller mounted ones --
with a screw-on single-sized collet adaptor.

Yes. It appears to be the earlier design. The hollow spindle design
allows one to change the business end without disassembling the grinder.

Right -- but you can change the business end with the screw-on
"chuck" just as easily.

After reading the manual, I now have to bold mine up on my
lathe, and see whether the spindle height can be set high enough (mine
is a 12" swing lathe, and they are specifying this toolpost grinder for
up to 11" swing). But if not, I can probably make a new center post for
the toolpost to allow it to be mounted a bit higher.

And -- I think that I'll also make a support collar so it will
be easy to restore to the proper height each time, since this is the
only lathe which I expect to use it on. It seems a bit too big for the
little Emco-Maier Compact-5/CNC -- a 5" swing machine. :-)

[ ... ]

I think that it would be difficult to adapt the typical
flashlamp to the purpose. And the diameter and base of the lamp are
needed, as it plugs into a socket on the end of the stub, and the flash
reflector slides on over the lamp once it is plugged in.

One does not have to duplicate these details. An electrical match will
generally work. Basically, one matches the flash voltage range (say 300
volts), the energy capacity (4 Joules/flash, max), trigger voltage (say
6 KV), and trigger energy (say 1 millijoule). (These are not the
correct values for the FX-6A, but give the idea.)

The thing is that most flashlamps use external trigger -- a wire
wrapped around the outside of the envelope. This one, however, has
internal trigger electrodes, and may operate with a much lower trigger
voltage.

[ ... ]

Selected General Radio stuff is now made by IET Labs www.ietlabs.com,
and they list flashlamps for $200 to $300, which I bet is more than old
Strobotacs go for on ebay.

It is about an order or magnitude more. I got a set of about
five or six FX-6A lamps from an ebay auction for a fairly reasonable
price, after losing an auction for a similar number which went into the
stratosphere -- at least based on what I was willing to pay. :-)

[ ... ]

Yep. My Strobotac goes up to 25K Flashes Per Minute. It is a
model 1531-A, FWIW. The older one with the dark gray crackle panel
finish, not the later one with the light gray smooth finish.

Hmm. If the flashtubes aren't too deal, this could be a good idea, even
if the tubes cost more than the unit.

You mean "aren't too dear"? Agreed. And if they are -- just
keep buying Strobotacs from eBay. :-)

Hmm -- auction # 7607110774 is up to $83.68 with 44 minutes to
go -- but it is one of the newer ones with the light gray smooth front
panel. Model 1538-A. A connector for an external flash head, but
otherwise quite similar.

Another auction (actually only "buy-it-now") is being offered
by a vendor with delusions of grandeur. This is auction # 7405976193
and has a *starting* price of $2,955.06 (actually it is priced in Euros,
at EUR 2,444.02).

The only other current auction is # 7607451350 -- one of the
older ones, with a less bright flash lamp, and (IIRC) a much lower speed
limit. None of the photos are from an orientation to show the
"soupbowl" reflector -- which may suggest problems with it. Normally, I
would expect, even from the views show, the bulge of the large crystal
to be visible. Since it is not -- it may be broken. And while it
*looks* like a GR unit from the views given -- it may not be by GR --
they say "Electric Brazing" -- which may have been a secondary
contract manufacturer during wartime or something similar.

Auction # 7607782129 looks interesting -- a much later digital
Strobotac -- but the vendor is in love with that one too -- $1,295.00
starting bid and $1,345.00 for buy-it-now.

FWIW -- The speed ranges a

Range Flashes Per Minute Flash Duration (approx.)
1 (LOW) 100 to 700 2sssss
2 (MED) 1600 to4,200 2sssss
3 (HIGH) 3,600 to 25,000 1.2

(I got a long phone call just before this point above -- just after the
auction number was entered. It will be interesting to see whether the
article has timed out while I was talking.

[ ... ]

I wonder if one can buy new wicks.

I suspect that one would need to make new wicks at this point.
You can get appropriate felt from McMaster Carr for the task.

True, but if I order the spindle oil, might as well get some pre-made
wicks. My unit did not come with a belt, and I ordered that some years
ago, just so I could try it out. At the time, I didn't really know what
a toolpost grinder was for. Grinding tool posts?

O.K. Some years ago I got a Dumore drill grinder, and got a
manual from them at that time. A couple of years later, I got the
toolpost grinder, and a phone call had them not having any manuals or
parts for toolpost grinders that old.

I can understand ditching the repair parts after 50 years, but how much
trouble would it have been to scan and post the old manuals? These old
units are quite well made, and so will always be with us.

They used to make them available -- for free. (At least the one
for the drill grinder was free.) They seem to have tossed all of the
old parts and manuals now.


If you haven't already, download the manual and the .txt page
posted to the dropbox (http://www.metalworking.com). The files are
under the names:

[ ... ]

Got them, Thanks. Would have liked the photos to be legible. Perhaps
we can impose on the poster to provide a high-rez scan as well.

If he can snail-mail a CD-ROM to me, I can put them on my web
site at full resolution. I can't receive e-mails over 30K in size -- to
keep viruses out of the mailing lists which I host. (And to keep me
from being flooded with each new issue -- to the tune of 200-300 per
day. :-)

But -- I'm not going to complain when he didn't have to do this
at all. I'm just passing on thanks.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote in message
...
According to Glenn :

The manual with exploded parts diagram is now in the drop box. I scaned
at
150 DPI enhanced text mode to keep it small so the B&W photos are not all
that wonderful.

Yep -- the photos are terrible (other than your direct scan of
the collet). -- but I think that I can make out what they are about.
These tradeoffs are necessary when file size is important.

The text and parts list is easily readable though. I
added
a scan of the collett adapter with the dimensions roughed in. Should
give
you all you need to make a servicable piece.

I believe that it will do for the task.

Thank you for this.

Quite Welcome

I think the exploded diagram will answer a lot of questions about how the
spindle and bearings go together.

Indeed so.


I think this manual was written before the lawsuit happy lawyers got
involved .. there really aren't many of the "warnings" you see in modern
manuals. Interestingly enough it does say to use only Dumore precision
balanced grinding wheels LOL

And also on page 2 is the all upper case:

"WARNING: DO NOT EXCEED WHEEL SPEED RECOMMENDATIONS."

(But no exclamation point at the end. :-)

The manual is obviously older than my grinder, because of the
lack of 3-pin power connectors. But it is obviously for the same
grinder, as the model number (first four digits of the serial number)
matches.

Kinda fun looking at these old manuals .. especially the price list :-)


Anyway if there is anything else you need for info or pictures let me
know.

I think that those will do the job for me. I already have them
printed out -- and the photos did not improve in the process. :-)

The added info in the .txt file will help as well. I am glad to
get confirmation that the spindle thread was originally 1/4-32.

Was there only the one "Chuck assembly" with a 1/8" bore? That
would appear to be the case, based on the parts list and drawing.

Only 1 chuck came with mine. There is a hombrew thing in there for holding
a stone but it has no threads and the stone is glued to the brass.

So -- the largest wheel really was a 2" one. I've got some
larger ones which I have adapted to the spindle which are still well
within their speed rating -- but perhaps the motor does not have the
horsepower to drive the larger wheels. I guess that I'll find out.

Mine drives a 2.5" wheel ok.

The design of the diamond holder is different than I had
expected -- but makes sense if you have to re-dress the wheel part-way
through the task.

I don't see the diamond holder listed in the parts list, nor in
the drawing.

Mine dosen't have the wheel dresser either but I intend to make one.

Again -- many thanks,
DoN.

Happy I could help.
Glenn

In article ,
Eric R Snow wrote:

On Tue, 11 Apr 2006 11:21:34 -0700, "Ken Davey"
wrote:


O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.

How so?

It can spin up to a fast enough RPM so the centrifugal force (I
know -- there really is no such thing) will cause it to fly apart
-- turning it into shrapnel -- and *you* into a target. I don't
know whether there is any size limit for this to happen, but it
has been known to happen and to harm or kill people nearby.

Ahh. I can see a large bearing being driven fast enough to explode,
especially as bearing races are designed to be reinforced by being
pressed into a recess in a larger housing.

However, One would think that overspeed isn't going to be an issue
with small bearings already specified for 30,000 rpm, unless one's
air supply is something else.


Spinnning a bearing with compressed air is a complete NONO!
Firstly this practice will ruin the bearing - think no lubrication.
Dangerous - as has been mentioned the bearing can explode and sometimes the
bearing will seize.
As the handiest workholder is a finger a seizure at high speed will severely
damage said workholder.

Cleaning with air is quite allright - oil the bearing immediately after such
treatment as moisture will be present in the air and/or will condence on the
(now) cold bearing.

Regards.
Ken

--
Volunteer your idle computer time for cancer research
http//www.grid.org/download/gold/download.htm
Return address courtesy of Spammotel http://www.spammotel.com/

Years ago I was blowing out some bearings with air. Goofing off, with
the bearing on my finger, I spun one up and listened to the pitch. As
it spun the pitch got higher until I couldn't hear it. Just as it
passed into my ultrasonic range it exploded with a bang.

Ultrasonic! Wow. That implies a ball-passing frequency exceeding
20,000 per second or so. If the ball cage has ten balls in it, the cage
is rotating at 2000 rps, or 120,000 rpm, and the outer race a factor
faster. No wonder it exploded.

Do you recall the dimensions of the deceased ball bearing?


The bearing
axis was perpendicular to my body so that the bearing parts were
embedded into the wall and not me. My finger hurt like hell. I think
the bearing must have exploded pretty equally because otherwise that
finger would have probably broken instead.

Yes. Lab ultra-centrifuges are built inside a heavy steel box, to
contain the shards of the rotor, when (not if) it explodes. When this
happens, the centrifuge is totally destroyed.


I don't spin up bearings
any more. Not even a little.

It sounds like there is actually quite a wide safe range here. Just
stay in the sonic range?

Joe Gwinn

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

[ ... ]

Ahh. I can see a large bearing being driven fast enough to explode,
especially as bearing races are designed to be reinforced by being
pressed into a recess in a larger housing.

However, One would think that overspeed isn't going to be an issue with
small bearings already specified for 30,000 rpm, unless one's air
supply is something else.

I think that it may be a function of the size of the air exit in
the nozzle vs the air pressure. But also -- depending on where you hit
the bearings, you can get speed multiplication -- probably the worst is
driving at the balls themselves, which could easily double the air
speed.

I'll have to think about this. One can compute the airstream velocity
at the output side of the orifice of the blowoff nozzle, and use this to
computer rpm. It would be hard for the airstream to get a purchase on
anything other than the balls - everything else is too smooth.

As you probably have seen already -- there was a followup posted
which strongly supports my warning.

Yes. With the siren song from balls passing through the air jet going
into the ultrasonic. I suppose it shouldn't be a surprise, as many
gyroscopes are spun up with compressed air (or helium).


O.K. At least the manual (I presume that you downloaded it as
well) does not say to not disassemble it.

I just downloaded the manual. Quite interesting.

Even if it does not precisely cover your version. How do the
model numbers compare? (The first four digits of the serial number).
Mine are an exact match.

Mine does not follow the rule in the Series 11 manual, but looks like
the parts breakdown diagram.


Interesting that there are different numbers (and different part
numbers) for the motor bearings depending on which end, but the spindle
bearings have the same number at each end.

They look the same too. The motor has a shaft coming out of one end
only, while the spindle has shafts coming out at both ends.

Right -- but that should not make any difference. Perhaps the
difference in the motor bearings is because only the pulley end of the
motor experiences side loads, while both ends of the spindle do.

Or -- the bearings *may* be identical. :-)

I haven't had the motor apart, so have no opinion.


It may depend on what you call "removable". Certainly the ones
which started this thread were designed to screw into a hollow spindle
with a taper, based on the photos. (Hmm ... has that auction closed,
yet? :-)

I think that the hollow spindle is a later design.

O.K. But the manual does show that for this model at least, the
same spindle is used for both larger wheels and smaller mounted ones --
with a screw-on single-sized collet adaptor.

Yes. It appears to be the earlier design. The hollow spindle design
allows one to change the business end without disassembling the grinder.

Right -- but you can change the business end with the screw-on
"chuck" just as easily.

True, but replacing the whole spindle is faster, and works even for
holes smaller than the spindle diameter. Quick change seems to be the
issue.


After reading the manual, I now have to hold mine up on my
lathe, and see whether the spindle height can be set high enough (mine
is a 12" swing lathe, and they are specifying this toolpost grinder for
up to 11" swing). But if not, I can probably make a new center post for
the toolpost to allow it to be mounted a bit higher.

And -- I think that I'll also make a support collar so it will
be easy to restore to the proper height each time, since this is the
only lathe which I expect to use it on. It seems a bit too big for the
little Emco-Maier Compact-5/CNC -- a 5" swing machine. :-)

Right. Now, Ill have to get a big enough lathe.


I think that it would be difficult to adapt the typical
flashlamp to the purpose. And the diameter and base of the lamp are
needed, as it plugs into a socket on the end of the stub, and the flash
reflector slides on over the lamp once it is plugged in.

One does not have to duplicate these details. An electrical match will
generally work. Basically, one matches the flash voltage range (say 300
volts), the energy capacity (4 Joules/flash, max), trigger voltage (say
6 KV), and trigger energy (say 1 millijoule). (These are not the
correct values for the FX-6A, but give the idea.)

The thing is that most flashlamps use external trigger -- a wire
wrapped around the outside of the envelope. This one, however, has
internal trigger electrodes, and may operate with a much lower trigger
voltage.

I think that the trigger is 4KV, but such things are far from critical.
I recently built a special-purpose strobe (for illuminating a coil
winder in motion), and couldn't initially get the right parts, using a
trigger transformer that was too weak for the right flashtube, and a
flashtube that required more trigger voltage than the correct tube, the
net deficit being (2:1)(6:4)= 3:1.

It worked anyway, albeit with the occasional misfire. When I rewired it
to double the trigger voltage, the misfires went away. This is with new
tubes. The problems will occur later, as things age. (I now have the
correct flashtube.) This uses an ordinary cheap flashtube, and runs at
up to about 40 Hz (2,400 rpm).

A bigger issue is how fast the tube deionizes. If it isn't fast enough,
one cannot flash the tube fast enough, as it stops flashing and instead
remains always on. Deionization time is mostly determined by flash tube
design.


Selected General Radio stuff is now made by IET Labs www.ietlabs.com,
and they list flashlamps for $200 to $300, which I bet is more than old
Strobotacs go for on ebay.

It is about an order or magnitude more. I got a set of about
five or six FX-6A lamps from an ebay auction for a fairly reasonable
price, after losing an auction for a similar number which went into the
stratosphere -- at least based on what I was willing to pay. :-)

[ ... ]

Yep. My Strobotac goes up to 25K Flashes Per Minute. It is a
model 1531-A, FWIW. The older one with the dark gray crackle panel
finish, not the later one with the light gray smooth finish.

Hmm. If the flashtubes aren't too deal, this could be a good idea, even
if the tubes cost more than the unit.

You mean "aren't too dear"? Agreed. And if they are -- just
keep buying Strobotacs from eBay. :-)

Yes, dear.

I have a question in at Perkin-Elmer asking if the FX-6A is still made,
and if not what is it's replacement (perhaps Series 1100), and what they
cost. We shall see.


Hmm -- auction # 7607110774 is up to $83.68 with 44 minutes to
go -- but it is one of the newer ones with the light gray smooth front
panel. Model 1538-A. A connector for an external flash head, but
otherwise quite similar.

Another auction (actually only "buy-it-now") is being offered
by a vendor with delusions of grandeur. This is auction # 7405976193
and has a *starting* price of $2,955.06 (actually it is priced in Euros,
at EUR 2,444.02).

Yes, for collectors only. This is about what a new unit from IET costs.


The only other current auction is # 7607451350 -- one of the
older ones, with a less bright flash lamp, and (IIRC) a much lower speed
limit. None of the photos are from an orientation to show the
"soupbowl" reflector -- which may suggest problems with it. Normally, I
would expect, even from the views show, the bulge of the large crystal
to be visible. Since it is not -- it may be broken. And while it
*looks* like a GR unit from the views given -- it may not be by GR --
they say "Electric Brazing" -- which may have been a secondary
contract manufacturer during wartime or something similar.

I saw that one. Never heard of the company.


Auction # 7607782129 looks interesting -- a much later digital
Strobotac -- but the vendor is in love with that one too -- $1,295.00
starting bid and $1,345.00 for buy-it-now.

Right. Check IET price first.


FWIW -- The speed ranges a

Range Flashes Per Minute Flash Duration (approx.)
1 (LOW) 100 to 700 2sssss
2 (MED) 1600 to 4,200 2sssss
3 (HIGH) 3,600 to 25,000 1.2

Sam Goldwasser has published a circuit for a three-range strobe that
goes to 6,000 flashes per second. Search for "strobex.pdf". This
circuit could achieve 25,000 fpm with the right tube, and some circuit
adjustments.


(I got a long phone call just before this point above -- just after the
auction number was entered. It will be interesting to see whether the
article has timed out while I was talking.

[ ... ]

I wonder if one can buy new wicks.

I suspect that one would need to make new wicks at this point.
You can get appropriate felt from McMaster Carr for the task.

True, but if I order the spindle oil, might as well get some pre-made
wicks. My unit did not come with a belt, and I ordered that some years
ago, just so I could try it out. At the time, I didn't really know
what
a toolpost grinder was for. Grinding tool posts?

O.K. Some years ago I got a Dumore drill grinder, and got a
manual from them at that time. A couple of years later, I got the
toolpost grinder, and a phone call had them not having any manuals or
parts for toolpost grinders that old.

I can understand ditching the repair parts after 50 years, but how much
trouble would it have been to scan and post the old manuals? These old
units are quite well made, and so will always be with us.

They used to make them available -- for free. (At least the one
for the drill grinder was free.) They seem to have tossed all of the
old parts and manuals now.

Annoying.


If you haven't already, download the manual and the .txt page
posted to the dropbox (http://www.metalworking.com). The files are
under the names:

Found them, under dumore.


Got them, Thanks. Would have liked the photos to be legible. Perhaps
we can impose on the poster to provide a high-rez scan as well.

If he can snail-mail a CD-ROM to me, I can put them on my web
site at full resolution. I can't receive e-mails over 30K in size -- to
keep viruses out of the mailing lists which I host. (And to keep me
from being flooded with each new issue -- to the tune of 200-300 per
day. :-)

But -- I'm not going to complain when he didn't have to do this
at all. I'm just passing on thanks.

True enough. If he wishes, he can email to me, and I will post the
files for him. I have no 30K limit. He can email to me, and I will
post the files. The email address above is real.

Joe Gwinn