Jim Wilkins wrote:
On Jul 3, 8:56 pm, "Michael Koblic" wrote:
Jim Wilkins wrote:
...

I am not sure I understand. How is the 4L belt dimension relevant to
the Taig? Are you saying I should change the whole drive train to
4L? Isn't it a bit big for the machine?

--
Michael Koblic

Why would you want to change the rest of the transmission to the Taig
style? An oversized motor and belts will cost you a little extra
electricity but you can easily make them slip to not overstress the
lathe.

1/2" pulleys and 3/4/5L vee belts are the only drive components
readily available from hardware stores on weekends, at least around
here. And they work well with small electric and gas motors. If you
build drives from surplus rather than carefully engineering them, it's
very helpful to have very few variations of shaft size and belt type,
so you can recycle the growing collection of spares when you move on
to air compressors and bandsaws.

Ah. I see the problem. We are talking at cross-purposes. The original
question I posed was about how critical the grooves were on the pulleys for
the *3M* belt (on the Taig). At that point Don N. and I were discussing how
to reduce the speed of the Taig. I quoted the wooden pulley as an example of
my next-to-nothing experience with making pulleys and wondering how
difficult it would be to make a custom pulley for the Taig.

The RedNeck lathe is a separate issue (coming along nicely, just got its own
stand and I have just semi-designed a toolpost for it).

BTW the belting on the RedNeck is part 4L (link belt - my best friend!) and
the part K-profile purely because those were the pulleys on the original
drill press. Given the choice they would all be 4L.

--
Michael Koblic
Campbell River, BC

Gunner Asch wrote:
On Fri, 03 Jul 2009 23:34:17 -0500, "Martin H. Eastburn"
wrote:

On the DC side, I scored a high torque motor - 4 brushes at 90
degrees -
that is 24V. Came out of a small elderly scooter. Some of these
are beginning to come on line in lew of second/third/fourth
generation 4 wheeler buggy/chair.

Martin

I might have some Omniturn 90vt DC servo motors. Encoders are likely
dead, but will run fine. Bout 3" in diameter, about 8" long with a
1/2"
shaft about 2" long.

Free but for the shipping if I can find em.


That is indeed tempting. Please let me know if you do find them and how much
for the shipping.

--
Michael Koblic
Campbell River, BC

On Sat, 4 Jul 2009 17:18:36 -0700, "Michael Koblic"
wrote:

Gunner Asch wrote:
On Fri, 03 Jul 2009 23:34:17 -0500, "Martin H. Eastburn"
wrote:

On the DC side, I scored a high torque motor - 4 brushes at 90
degrees -
that is 24V. Came out of a small elderly scooter. Some of these
are beginning to come on line in lew of second/third/fourth
generation 4 wheeler buggy/chair.

Martin

I might have some Omniturn 90vt DC servo motors. Encoders are likely
dead, but will run fine. Bout 3" in diameter, about 8" long with a
1/2"
shaft about 2" long.

Free but for the shipping if I can find em.


That is indeed tempting. Please let me know if you do find them and how much
for the shipping.

I will certainly do that.

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

On 2009-07-04, Michael Koblic wrote:
DoN. Nichols wrote:
[...]

But consider things like an old Singer sewing machine motor and
controller (such are are on the model 221 portable). It is simply a
DC/universal motor and a foot pedal which controls the current to the
motor (AC, but DC would work just as well). The foot pedal is simply
a stack of blocks of resistance element between two electrodes. The
harder you step on the pedal, the harder the blocks are pressed
together, and the lower the resistance, so the faster the motor runs.

I cannot imagine that a lot of torque was required of Singer sewing
machines. What hapens to torque at the lowest speeds?

Enough to handle sewing through leather to make thumbstraps for
English system concertinas. (Granted, you are part of the feedback,
adjusting the pressure as needed to maintain the speed which you can
work with.

[ ... ]

3) I have a DC motor from an old Sears drill sitting somewhere. As
it stands it would also need the whole gear box to get the speed
down to something useable. The speed regulation with it is basically
the slow start. When it is turning slowly there is hardly any torque
which brings me back to (1).

This sounds good -- until you mention later that it is a 12V
motor, not a 120V motor.

I got one of them drills, too. But again, what happens to the torque at the
low speed if using a rheostat? On mine there is a slow start feature which I
take to be nothing more than a rheostat. I can stop the chuck by hand at the
low speed.

At absolutely the lowest speed, yes it is easy to stall. If you
have a foot pedal, you are adjusting the pressure to maintain the speed
you want, so it is no problem.

And remember that you are also *first* using the maximum *belt*
speed reduction to keep the motor's speed up a bit.

4) It is a thought to make a controller along the lines in (1) for
the motor. However, given that the motor is a 12V one I usspect that
the current at the lower speeds would be appreciable.

You want a drill which plugs directly into the AC line, not one
which runs from batteries.

I got a 13.6V 20A power supply - that's 1/3HP.

Just 13.6V or variable voltage all the way down to zero? If the
latter, you can use it with a 12V drill motor to get variable speed.

A TRIAC based speed controller will need AC on the input, but a
DC motor is normally also a Universal motor -- unless it has a permanent
magnet field -- which you are more likely to find in a good servo motor,
which is overkill for the task. So -- with a TRIAC based controller
(which could include something as simple as a lamp dimmer) you want 120
VAC input, and a 120V DC/universal motor.

[...]

Oh -- you are thinking of two belts on each pulley except the
end ones. That restricts you to combinations which don't need the
same groove for both incoming and outgoing power. And I think the
lowest
speed with triple reduction would be both too slow for the size of the
machine and those tiny belts could not handle the transmission of
power over the last two stages.

63 rpm. But I take the point about the torque.

Likely too slow for that small a machine -- especially if you
don't have a threading setup with halfnuts and a dial to say when to
engage the halfnuts.

[ ... ]

O.K. Looking in McMaster Carr's web site, I find 1/2" wide belt
pulleys with a 0.200" pitch (MXL series). Let's see the largest
which will fit within 5" diameter.

The range for this size is 60 teeth max and 10 teeth minimum, or
6:1 ratio.

OD Teeth Bore Cat No Price

0.87" 10 3/16" 57105K11 $7.40
1.13" 14 1/4" 57105K14 $7.51
3.80" 60 5/16" 57105K33 $17.15

So -- if you need to fit it on a 1/4" shaft, you will need at leat 14
teeth (60:14 ratio, or about 128 RPM for 550 RPM in.

If you can turn the end of the shaft down to 3/16", you get a full 6:1
ratio, or 91 RPM.

These (and others) are on McMaster Carr's catalog page 1044 via
the web. (You'll also need to select a belt to fit including the
proper spacing between pulleys.) The pulleys which I have listed are
acetal plastic, and I would suggest that you go for the steel ones
listed a bit later in the page for stronger gears. And you'll
probably need to pin
the hubs instead of just use setscrews to get enough strength with the
small diameter shafts.

This would mean turning the spindle shaft down to at least 3/8". I do not
think this is possible. AFAIK the spindle is 5/8" with a 5/16" ID. Some of
the plain bore pulleys have large enough bores but maximum of 24 teeth or
so.

Look at the hub diameter in the pulley data. You should be able
to bore it out to fit the existing spindle. I would *never* consider
turning down the spindle to fit the pulley -- always modify the least
expensive and easiest to replace part.

And you won't want to be stepping up speed to the spindle, so
the larger pulley will be on the spindle, thus with the largest hub
diameter too.

Or -- go for the taper-lock type hubs where you can change hubs
to fit the shaft once you have the right pulley.

It is beginning to feel like trying to make a silk purse out of a sow's ear.
Some limitations will have to be accepted I think.

:-)

12" swing,
Increased rigidity,
The Holy Grail...

How about 18" swing or larger? :-) It all depends on what you
want to make. In this case, how large a dial do you want for your
sundials? You *could* use a gap-bed lathe for that -- but there can be
problems getting the gap insert back in precisely enough so it does not
affect accuracy of turning close to the headstock.

I do know that I occasionally find projects which would go
better with a larger lathe -- but I don't really have room for one.

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 ---

On 2009-07-04, wrote:
On Jul 4, 1:36*am, "DoN. Nichols" wrote:


* * * * Someone else suggested a light dimmer which is typically quite
inexpensive -- and as for motors -- a cheap hand held electric drill
could be clamped onto a shaft in bearings to drive at a lower speed. *
Or -- you could salvage a motor out of a vacuum cleaner or a kitchen
blender or anything else with a DC/universal motor. *(Just look for
brush holders to verify that it is not AC only -- and the holders may
be hidden inside, as is common in cheap hand held electric drills.)


* * * * Enjoy,
* * * * * * * * DoN.

That someone was me. Light dimmers work pretty well. They are a
stiffer source than a variac,

Perhaps stiffer than a Variac rated to match the load, but if
you have a 7A Variac or larger (I've worked with 20A 240V ones) I
challenge you to get stiffer. :-)

and I believe the back emf from the
motor affects when the triac fires.

Hmm ... that could be helpful as feedback.

Another source for universal motors is WeedWackers. I bought one at a
garage sale recently for $5.

O.K. That might be about the HP range needed for the Taig.

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
...

[...]

I cannot imagine that a lot of torque was required of Singer sewing
machines. What hapens to torque at the lowest speeds?

Enough to handle sewing through leather to make thumbstraps for
English system concertinas. (Granted, you are part of the feedback,
adjusting the pressure as needed to maintain the speed which you can
work with.

That cleared that up...:-)

[ ... ]

I got one of them drills, too. But again, what happens to the torque at
the
low speed if using a rheostat? On mine there is a slow start feature
which I
take to be nothing more than a rheostat. I can stop the chuck by hand at
the
low speed.

At absolutely the lowest speed, yes it is easy to stall. If you
have a foot pedal, you are adjusting the pressure to maintain the speed
you want, so it is no problem.

It is standing on one leg while turning I am a bit concerned about :-)

And remember that you are also *first* using the maximum *belt*
speed reduction to keep the motor's speed up a bit.

The whole thing (Singer, foot pedal etc.) has a certain attraction to it. A
sort of Kalashnikov feedback. When the time comes I shall explore this
concept.

I got a 13.6V 20A power supply - that's 1/3HP.

Just 13.6V or variable voltage all the way down to zero? If the
latter, you can use it with a 12V drill motor to get variable speed.

It is fixed but making a solid state voltage controller is no problem.
Others have put me off doing that because of the feedback issues discussed
earlier.

[...]

O.K. Looking in McMaster Carr's web site, I find 1/2" wide belt
pulleys with a 0.200" pitch (MXL series). Let's see the largest
which will fit within 5" diameter.

The range for this size is 60 teeth max and 10 teeth minimum, or
6:1 ratio.

OD Teeth Bore Cat No Price

0.87" 10 3/16" 57105K11 $7.40
1.13" 14 1/4" 57105K14 $7.51
3.80" 60 5/16" 57105K33 $17.15

So -- if you need to fit it on a 1/4" shaft, you will need at leat 14
teeth (60:14 ratio, or about 128 RPM for 550 RPM in.

If you can turn the end of the shaft down to 3/16", you get a full 6:1
ratio, or 91 RPM.

These (and others) are on McMaster Carr's catalog page 1044 via
the web. (You'll also need to select a belt to fit including the
proper spacing between pulleys.) The pulleys which I have listed are
acetal plastic, and I would suggest that you go for the steel ones
listed a bit later in the page for stronger gears. And you'll
probably need to pin
the hubs instead of just use setscrews to get enough strength with the
small diameter shafts.

This would mean turning the spindle shaft down to at least 3/8". I do not
think this is possible. AFAIK the spindle is 5/8" with a 5/16" ID. Some
of
the plain bore pulleys have large enough bores but maximum of 24 teeth
or
so.

Look at the hub diameter in the pulley data. You should be able
to bore it out to fit the existing spindle. I would *never* consider
turning down the spindle to fit the pulley -- always modify the least
expensive and easiest to replace part.

I somehow asumed that it was not a done thing to bore out the *finished*
pulleys as they make the plain pulleys that *are* meant to be bored to
specs.
Looking at the 57105K3 the hub is 7/8" which after boring to 5/8" ID would
leave walls 1/8" thick. You think that is all right? The 6495K733 is steel
and has a 1.5" hub.

The other issue I thought was that using the exisiting Taig step pulley on
the countershaft together with, say, 6495K713, would lead to an ID
mismatch which could not be corrected by boring alone (this one has a hub of
only 1/2"). Some sort of bushing for the Taig pulley perhaps?

And you won't want to be stepping up speed to the spindle, so
the larger pulley will be on the spindle, thus with the largest hub
diameter too.

Or -- go for the taper-lock type hubs where you can change hubs
to fit the shaft once you have the right pulley.

Presumably you are referring to something like this: 6495K222. The cost is
getting up there.

It is beginning to feel like trying to make a silk purse out of a sow's
ear.
Some limitations will have to be accepted I think.

:-)

12" swing,
Increased rigidity,
The Holy Grail...

How about 18" swing or larger? :-) It all depends on what you
want to make. In this case, how large a dial do you want for your
sundials? You *could* use a gap-bed lathe for that -- but there can be
problems getting the gap insert back in precisely enough so it does not
affect accuracy of turning close to the headstock.

I do know that I occasionally find projects which would go
better with a larger lathe -- but I don't really have room for one.

Oh, about 12 feet I guess:

http://www.milesfaster.co.uk/gallery...k/sun-dial.htm

But one has to walk before one can run. Also one must consider the size of
the etching bath, how many gallon bottles of Ferric Chloride one would need,
etc...

--
Michael Koblic
Campbell River, BC

On 2009-07-06, Michael Koblic wrote:

"DoN. Nichols" wrote in message
...

[...]

I cannot imagine that a lot of torque was required of Singer sewing
machines. What hapens to torque at the lowest speeds?

Enough to handle sewing through leather to make thumbstraps for
English system concertinas. (Granted, you are part of the feedback,
adjusting the pressure as needed to maintain the speed which you can
work with.

That cleared that up...:-)

A person for feedback can help a lot.

[ ... ]

I got one of them drills, too. But again, what happens to the torque at
the
low speed if using a rheostat? On mine there is a slow start feature
which I
take to be nothing more than a rheostat. I can stop the chuck by hand at
the
low speed.

At absolutely the lowest speed, yes it is easy to stall. If you
have a foot pedal, you are adjusting the pressure to maintain the speed
you want, so it is no problem.

It is standing on one leg while turning I am a bit concerned about :-)

You put it on a lower surface, and sit down so your foot is more
comfortable. :-)

And remember that you are also *first* using the maximum *belt*
speed reduction to keep the motor's speed up a bit.

The whole thing (Singer, foot pedal etc.) has a certain attraction to it. A
sort of Kalashnikov feedback. When the time comes I shall explore this
concept.

O.K.

I got a 13.6V 20A power supply - that's 1/3HP.

Just 13.6V or variable voltage all the way down to zero? If the
latter, you can use it with a 12V drill motor to get variable speed.

It is fixed but making a solid state voltage controller is no problem.

Given the current involved, you probably want to make it a
switching regulator instead of a linear one to reduce the power lost as
heat -- and the size of the heat sinks needed.

Others have put me off doing that because of the feedback issues discussed
earlier.

The larger the machine the more feedback you need -- or the
stiffer a motor to start with. In this case, you are going through
quite a bit of speed reduction, so you may be surprised at what the
motor can handle -- especially if you go with a timing belt and pulleys
for the last stage.

[ ... ]

This would mean turning the spindle shaft down to at least 3/8". I do not
think this is possible. AFAIK the spindle is 5/8" with a 5/16" ID. Some
of
the plain bore pulleys have large enough bores but maximum of 24 teeth
or
so.

Look at the hub diameter in the pulley data. You should be able
to bore it out to fit the existing spindle. I would *never* consider
turning down the spindle to fit the pulley -- always modify the least
expensive and easiest to replace part.

I somehow asumed that it was not a done thing to bore out the *finished*
pulleys as they make the plain pulleys that *are* meant to be bored to
specs.
Looking at the 57105K3

You mean 57105K33? That is acetal with an aluminum hub, which
would be too weak to handle that kind of treatment -- or the kind of
loads involved. Steel would be better (and more expensive, of course.
:-) Perhaps Acetal for the smaller end pulley, and steel for the larger
end on the lathe's spindle.

the hub is 7/8" which after boring to 5/8" ID would
leave walls 1/8" thick. You think that is all right? The 6495K733 is steel
and has a 1.5" hub.

Put more information about the pulleys. I'm going to have to go
back to McMaster Carr's web site and print out that page.

Anyway -- even if pinned, that one is acetal on aluminum. No, go
for the steel -- you get more hub to bore and to hold the setscrews.

The other issue I thought was that using the exisiting Taig step pulley on
the countershaft together with, say, 6495K713, would lead to an ID
mismatch which could not be corrected by boring alone (this one has a hub of
only 1/2"). Some sort of bushing for the Taig pulley perhaps?

Or -- start out with a shaft which fits the Taig pulley, and
turn one end down to accept the smaller pulley.

And you won't want to be stepping up speed to the spindle, so
the larger pulley will be on the spindle, thus with the largest hub
diameter too.

Or -- go for the taper-lock type hubs where you can change hubs
to fit the shaft once you have the right pulley.

Presumably you are referring to something like this: 6495K222. The cost is
getting up there.

No -- those are cylindrical bores. Look at "57095K11" -- and in
particular "57095K112" which is for a 5/8" shaft. But the problem is
one of finding the right timing pulleys to fit. These are for larger
belts ('H' (heavy) series, not 'L' or 'XL'.)

And I would not worry about boring out the larger pulley to fit.
You'll need means for measuring your bore to know when you are at the
right size -- which probably means making up a sample shaft with a step
0.010" too small, one 0.005" too small, one the right size, and one
about 0.002" too large. Stop before the too large will fit in. And be
sure to remove the setscrews before you start boring. Hold it by the
hub in the 4-jaw, and take a lot of time tuning it to on center before
you start boring.

[ ... ]

12" swing,
Increased rigidity,
The Holy Grail...

How about 18" swing or larger? :-) It all depends on what you
want to make. In this case, how large a dial do you want for your
sundials? You *could* use a gap-bed lathe for that -- but there can be
problems getting the gap insert back in precisely enough so it does not
affect accuracy of turning close to the headstock.

I do know that I occasionally find projects which would go
better with a larger lathe -- but I don't really have room for one.

Oh, about 12 feet I guess:

http://www.milesfaster.co.uk/gallery...k/sun-dial.htm

Hmm ... I'll bet that was not made on a lathe, but rather formed
up from stainless steel, and welded into shape. If it were solid enough
to turn on a lathe, the supports probably would not hold it. :-)

But one has to walk before one can run. Also one must consider the size of
the etching bath, how many gallon bottles of Ferric Chloride one would need,

The markings on that one were welded onto the stainless steel
surface, not etched into them. As the scale goes up, the production
means must change.

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
...

[...]

It is standing on one leg while turning I am a bit concerned about :-)

You put it on a lower surface, and sit down so your foot is more
comfortable. :-)

Yes. Cossack dancing - not my forte...

And remember that you are also *first* using the maximum *belt*
speed reduction to keep the motor's speed up a bit.

The whole thing (Singer, foot pedal etc.) has a certain attraction to it.
A
sort of Kalashnikov feedback. When the time comes I shall explore this
concept.

O.K.

[ ... ]

I somehow asumed that it was not a done thing to bore out the *finished*
pulleys as they make the plain pulleys that *are* meant to be bored to
specs.
Looking at the 57105K3

You mean 57105K33?

Must have clipped it pasting.

That is acetal with an aluminum hub, which
would be too weak to handle that kind of treatment -- or the kind of
loads involved. Steel would be better (and more expensive, of course.
:-) Perhaps Acetal for the smaller end pulley, and steel for the larger
end on the lathe's spindle.

the hub is 7/8" which after boring to 5/8" ID
would
leave walls 1/8" thick. You think that is all right? The 6495K733 is
steel
and has a 1.5" hub.

Put more information about the pulleys. I'm going to have to go
back to McMaster Carr's web site and print out that page.

Or get Explorer 7 or 8 with tabs.

Anyway -- even if pinned, that one is acetal on aluminum. No, go
for the steel -- you get more hub to bore and to hold the setscrews.

The other issue I thought was that using the exisiting Taig step pulley
on
the countershaft together with, say, 6495K713, would lead to an ID
mismatch which could not be corrected by boring alone (this one has a hub
of
only 1/2"). Some sort of bushing for the Taig pulley perhaps?

Or -- start out with a shaft which fits the Taig pulley, and
turn one end down to accept the smaller pulley.

Makes sense.

And you won't want to be stepping up speed to the spindle, so
the larger pulley will be on the spindle, thus with the largest hub
diameter too.

Or -- go for the taper-lock type hubs where you can change hubs
to fit the shaft once you have the right pulley.

Presumably you are referring to something like this: 6495K222. The cost
is
getting up there.

No -- those are cylindrical bores. Look at "57095K11" -- and in
particular "57095K112" which is for a 5/8" shaft. But the problem is
one of finding the right timing pulleys to fit. These are for larger
belts ('H' (heavy) series, not 'L' or 'XL'.)

I thought the 57095K11 is a bushing used with a sprocket, not a pulley per
se. The 6495K222 is used with 6086K14 quick disconnect bushing which is
available with a 5/8" bore. But the bushing and pulley combo is close to
$100.
The small pulley that should match it (L series) is 6495K23. This one is
steel, the bigger one is cast iron.

And I would not worry about boring out the larger pulley to fit.
You'll need means for measuring your bore to know when you are at the
right size -- which probably means making up a sample shaft with a step
0.010" too small, one 0.005" too small, one the right size, and one
about 0.002" too large. Stop before the too large will fit in. And be
sure to remove the setscrews before you start boring. Hold it by the
hub in the 4-jaw, and take a lot of time tuning it to on center before
you start boring.

A telescopic gauge?

[ ... ]

http://www.milesfaster.co.uk/gallery...k/sun-dial.htm

Hmm ... I'll bet that was not made on a lathe, but rather formed
up from stainless steel, and welded into shape. If it were solid enough
to turn on a lathe, the supports probably would not hold it. :-)

But one has to walk before one can run. Also one must consider the size
of
the etching bath, how many gallon bottles of Ferric Chloride one would
need,

The markings on that one were welded onto the stainless steel
surface, not etched into them. As the scale goes up, the production
means must change.

Please! I do not just copy other people's work! Well, not too often. Also,
if you have a hammer suddenly there is an awful lot of nails about.

--
Michael Koblic
Campbell River, BC

continuation of the "References: " header, which is growing long
enough so it is likely to start creating problems, so I've
moved this part to the body.








On 2009-07-08, Michael Koblic wrote:


"DoN. Nichols" wrote in message
...

[ ... ]

I somehow asumed that it was not a done thing to bore out the *finished*
pulleys as they make the plain pulleys that *are* meant to be bored to
specs.
Looking at the 57105K3

You mean 57105K33?

Must have clipped it pasting.

That happens.

That is acetal with an aluminum hub, which
would be too weak to handle that kind of treatment -- or the kind of
loads involved. Steel would be better (and more expensive, of course.
:-) Perhaps Acetal for the smaller end pulley, and steel for the larger
end on the lathe's spindle.

the hub is 7/8" which after boring to 5/8" ID
would
leave walls 1/8" thick. You think that is all right? The 6495K733 is
steel
and has a 1.5" hub.

Put more information about the pulleys. I'm going to have to go
back to McMaster Carr's web site and print out that page.

Or get Explorer 7 or 8 with tabs.

Exactly how would that help me?

1) I *can't* run Explorer of any version on my Sun Workstation,
which is what I use for browsing, newsreading, and for e-mail.
I won't allow a Windows system to touch the outside net from my
network. It is too easy to have one get a virus and then start
spewing out spam to the world, giving my network a bad name.

2) Tabs (which I do have in the Opera browser which I use by
choice) would only help if I were doing both the catalog
checking and the news editing on the browser at the same time.
I *don't* and *won't* use a browser as a newsreader -- I use a
*real* newsreader (better than any implementation in a browser)
and don't use Google for accessing news.

3) Scrolling around on the catalog page using a browser is not as
easy nor as quick as printing out the catalog page and scanning
it beside my keyboard. (Among other things, in the browser, I
have to scroll back up to find out what the column headings are,
and sometimes all the way to the top

[ ... ]

And you won't want to be stepping up speed to the spindle, so
the larger pulley will be on the spindle, thus with the largest hub
diameter too.

Or -- go for the taper-lock type hubs where you can change hubs
to fit the shaft once you have the right pulley.

Presumably you are referring to something like this: 6495K222. The cost
is
getting up there.

No -- those are cylindrical bores. Look at "57095K11" -- and in
particular "57095K112" which is for a 5/8" shaft. But the problem is
one of finding the right timing pulleys to fit. These are for larger
belts ('H' (heavy) series, not 'L' or 'XL'.)

I thought the 57095K11 is a bushing used with a sprocket, not a pulley per
se.

I've seen the same type of bushings used on timing belts, and
actually *have* some on my CNC Bridgeport.

The 6495K222 is used with 6086K14 quick disconnect bushing which is
available with a 5/8" bore. But the bushing and pulley combo is close to
$100.

I didn't find the bushing itself, and could not see how well it
would work for this task. I *wish* that McMaster Carr would make their
catalogs more readily available.

The small pulley that should match it (L series) is 6495K23. This one is
steel, the bigger one is cast iron.

O.K. Cast Iron is fine for the task. It is the softer metals
like the aluminum hub, and the softer plastics like the acetal (Delrin)
body which are likely to be problems for your job.

And I would not worry about boring out the larger pulley to fit.
You'll need means for measuring your bore to know when you are at the
right size -- which probably means making up a sample shaft with a step
0.010" too small, one 0.005" too small, one the right size, and one
about 0.002" too large. Stop before the too large will fit in. And be
sure to remove the setscrews before you start boring. Hold it by the
hub in the 4-jaw, and take a lot of time tuning it to on center before
you start boring.

A telescopic gauge?

Do you have one which will go small enough? I forget whether
that or a split ball-end gauge is the better fit for that size. I've
got both -- plus some Tesa/B&S Tri-Mikes for more accurate bore
readings.

But accurate reading of either the split balls or the telescoping
gauges with a micrometer takes some experience to get accurte and
repeatable readings, which is why I suggested that you make a gauging
fixture which will be quick and easy to use, and especially to tell you
when to start sneaking up on the final dimension.

[ ... ]

http://www.milesfaster.co.uk/gallery...k/sun-dial.htm

Hmm ... I'll bet that was not made on a lathe, but rather formed
up from stainless steel, and welded into shape. If it were solid enough
to turn on a lathe, the supports probably would not hold it. :-)

But one has to walk before one can run. Also one must consider the size
of
the etching bath, how many gallon bottles of Ferric Chloride one would
need,

The markings on that one were welded onto the stainless steel
surface, not etched into them. As the scale goes up, the production
means must change.

Please! I do not just copy other people's work!

A good stainless steel won't etch with the Ferric Chloride
anyway, so you'll need some other way to attach the number markings to
something of that size designed for outdoor exposure. I was talking
about how it made sense to make it -- not how to copy someone else's
work. You could form the letters with weld markings, or rivet them in
place, or any of a number of other possibilities.

Well, not too often. Also,
if you have a hammer suddenly there is an awful lot of nails about.

But when the workpiece is the size of Big Ben, nails don't do
much good, even if you have the best hammer in the world. :-)

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:

[ ... ]

Or get Explorer 7 or 8 with tabs.

Exactly how would that help me?

1) I *can't* run Explorer of any version on my Sun Workstation,
which is what I use for browsing, newsreading, and for e-mail.
I won't allow a Windows system to touch the outside net from my
network. It is too easy to have one get a virus and then start
spewing out spam to the world, giving my network a bad name.

2) Tabs (which I do have in the Opera browser which I use by
choice) would only help if I were doing both the catalog
checking and the news editing on the browser at the same time.
I *don't* and *won't* use a browser as a newsreader -- I use a
*real* newsreader (better than any implementation in a browser)
and don't use Google for accessing news.

3) Scrolling around on the catalog page using a browser is not as
easy nor as quick as printing out the catalog page and scanning
it beside my keyboard. (Among other things, in the browser, I
have to scroll back up to find out what the column headings are,
and sometimes all the way to the top

Chacun a son gout...

[ ... ]

The 6495K222 is used with 6086K14 quick disconnect bushing
which is available with a 5/8" bore. But the bushing and pulley
combo is close to $100.

I didn't find the bushing itself, and could not see how well it
would work for this task. I *wish* that McMaster Carr would make
their catalogs more readily available.

The small pulley that should match it (L series) is 6495K23. This
one is steel, the bigger one is cast iron.

O.K. Cast Iron is fine for the task. It is the softer metals
like the aluminum hub, and the softer plastics like the acetal
(Delrin) body which are likely to be problems for your job.

I suspect it is all academic.

And I would not worry about boring out the larger pulley to fit.
You'll need means for measuring your bore to know when you are at
the right size -- which probably means making up a sample shaft
with a step
0.010" too small, one 0.005" too small, one the right size, and one
about 0.002" too large. Stop before the too large will fit in. And
be sure to remove the setscrews before you start boring. Hold it
by the hub in the 4-jaw, and take a lot of time tuning it to on
center before you start boring.

A telescopic gauge?

Do you have one which will go small enough? I forget whether
that or a split ball-end gauge is the better fit for that size. I've
got both -- plus some Tesa/B&S Tri-Mikes for more accurate bore
readings.

But accurate reading of either the split balls or the telescoping
gauges with a micrometer takes some experience to get accurte and
repeatable readings, which is why I suggested that you make a gauging
fixture which will be quick and easy to use, and especially to tell
you when to start sneaking up on the final dimension.

Well, it is a close run thing between using the telescopic gauge and a
micrometer and actually making something with the required accuracy. The
last two attempts at making something to a given dimension I overshot by
0.010" and 0.004" respectively. I suppose I am getting better...

The markings on that one were welded onto the stainless steel
surface, not etched into them. As the scale goes up, the production
means must change.

Please! I do not just copy other people's work!

A good stainless steel won't etch with the Ferric Chloride
anyway,

That it won't...

so you'll need some other way to attach the number markings to
something of that size designed for outdoor exposure. I was talking
about how it made sense to make it -- not how to copy someone else's
work. You could form the letters with weld markings, or rivet them in
place, or any of a number of other possibilities.

Done the rivet bit .


Well, not too often.
Also,
if you have a hammer suddenly there is an awful lot of nails about.

But when the workpiece is the size of Big Ben, nails don't do
much good, even if you have the best hammer in the world. :-)

Maybe I shall limit myself to 12". It has served me well thus far.

--
Michael Koblic
Campbell River, BC

On 2009-07-09, Michael Koblic wrote:
DoN. Nichols wrote:

[ ... ]

Or get Explorer 7 or 8 with tabs.

Exactly how would that help me?

1) I *can't* run Explorer of any version on my Sun Workstation,

[ ... ]

Chacun a son gout...

After all -- I don't have to worry about the usual virus
infections with the Sun Workstation. They are all targeted at the
easiest target -- Windows. :-)

[ ... ]

The small pulley that should match it (L series) is 6495K23. This
one is steel, the bigger one is cast iron.

O.K. Cast Iron is fine for the task. It is the softer metals
like the aluminum hub, and the softer plastics like the acetal
(Delrin) body which are likely to be problems for your job.

I suspect it is all academic.

O.K. If you are considering purchasing a larger lathe (as
suggested by the questions about lubrication), yes it is more than you
need to do.

And I would not worry about boring out the larger pulley to fit.
You'll need means for measuring your bore to know when you are at
the right size -- which probably means making up a sample shaft
with a step
0.010" too small, one 0.005" too small, one the right size, and one
about 0.002" too large. Stop before the too large will fit in. And
be sure to remove the setscrews before you start boring. Hold it
by the hub in the 4-jaw, and take a lot of time tuning it to on
center before you start boring.

A telescopic gauge?

Do you have one which will go small enough? I forget whether
that or a split ball-end gauge is the better fit for that size. I've
got both -- plus some Tesa/B&S Tri-Mikes for more accurate bore
readings.

But accurate reading of either the split balls or the telescoping
gauges with a micrometer takes some experience to get accurate and
repeatable readings, which is why I suggested that you make a gauging
fixture which will be quick and easy to use, and especially to tell
you when to start sneaking up on the final dimension.

Well, it is a close run thing between using the telescopic gauge and a
micrometer and actually making something with the required accuracy. The
last two attempts at making something to a given dimension I overshot by
0.010" and 0.004" respectively. I suppose I am getting better...

Hmm ... first trick is to make sure that the tool is quite
sharp.

Second is to feed something like 1/3 the distance to reach final
diameter, make your cut, and measure what you really got, comparing it
to what you expected. Divide what is left by two, and adjust by how far
off your previous result was. Feed in that much, and make another cut
and measure again. Adjust again for the final cut.

It is difficult to get a very light cut to produce what you
want, because deflection of the workpiece and the tool may prevent ever
taking a bite, so when you finally feed enough to take another bite, it
is too big. So sneaking up on the final dimension can be difficult, and
making larger cuts works better.

As for getting the boring to work right -- bore to a few
thousandths undersized, and then use a reamer to get to final size. The
same problems with sneaking up on the size occur when boring as when
turning -- perhaps more so.

[ ... ]

Also,
if you have a hammer suddenly there is an awful lot of nails about.

But when the workpiece is the size of Big Ben, nails don't do
much good, even if you have the best hammer in the world. :-)

Maybe I shall limit myself to 12". It has served me well thus far.

O.K.

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 ---

On Jul 8, 10:40*pm, "DoN. Nichols" wrote:
On 2009-07-09, Michael Koblic wrote:
...
* * * * Hmm ... first trick is to make sure that the tool is quite
sharp.

* * * * Second is to feed something like 1/3 the distance to reach final
diameter, make your cut, and measure what you really got, comparing it
to what you expected. *Divide what is left by two, and adjust by how far
off your previous result was. *Feed in that much, and make another cut
and measure again. *Adjust again for the final cut.

* * * * It is difficult to get a very light cut to produce what you
want, because deflection of the workpiece and the tool may prevent ever
taking a bite, so when you finally feed enough to take another bite, it
is too big. *So sneaking up on the final dimension can be difficult, and
making larger cuts works better.

* * * * As for getting the boring to work right -- bore to a few
thousandths undersized, and then use a reamer to get to final size. *The
same problems with sneaking up on the size occur when boring as when
turning -- perhaps more so.

You can check if the tool will shave off a fraction of a thousandth
while you're still a few thousandths out and can safely remove and
hone it.

When I have difficulty with a fit I make the start of the bore or the
shaft slightly tapered by filing or cutting steps, press the parts
together enough to make marks, then cut down to almost remove those
marks. Candle flame soot or marker ink makes them easier to see.

jsw

DoN. Nichols wrote:

[ ... ]

Chacun a son gout...

After all -- I don't have to worry about the usual virus
infections with the Sun Workstation. They are all targeted at the
easiest target -- Windows. :-)

Yes. Mine has caught the swine flu I think.

[ ... ]

The small pulley that should match it (L series) is 6495K23. This
one is steel, the bigger one is cast iron.

O.K. Cast Iron is fine for the task. It is the softer metals
like the aluminum hub, and the softer plastics like the acetal
(Delrin) body which are likely to be problems for your job.

I suspect it is all academic.

O.K. If you are considering purchasing a larger lathe (as
suggested by the questions about lubrication), yes it is more than you
need to do.

It is all about understanding the options and then making the right choice.
The one big unknown is the future performance of the RedNeck beast. I made a
toolpost for it (well, a boring bar holder really) and it will be ready to
go tomorrow. If it does half a decent job the pressure is off.

[...]

Well, it is a close run thing between using the telescopic gauge and
a micrometer and actually making something with the required
accuracy. The last two attempts at making something to a given
dimension I overshot by
0.010" and 0.004" respectively. I suppose I am getting better...

Hmm ... first trick is to make sure that the tool is quite
sharp.

As well as the operator.

Second is to feed something like 1/3 the distance to reach final
diameter, make your cut, and measure what you really got, comparing it
to what you expected. Divide what is left by two, and adjust by how
far off your previous result was. Feed in that much, and make
another cut and measure again. Adjust again for the final cut.

It is difficult to get a very light cut to produce what you
want, because deflection of the workpiece and the tool may prevent
ever taking a bite, so when you finally feed enough to take another
bite, it is too big. So sneaking up on the final dimension can be
difficult, and making larger cuts works better.

I am still struggling to understand fully what happens if you run the tool
over the workpiece in two or three passes without adjusting the feed at all.
This applies to both the mill and the lathe. In both cases it was the
finishing cut that took me past the specified dimension.

As for getting the boring to work right -- bore to a few
thousandths undersized, and then use a reamer to get to final size.
The same problems with sneaking up on the size occur when boring as
when turning -- perhaps more so.

I guess this is OK up to about 1/2". Economy-wise.

Talking about economy: I went to visit the shop that sells my stuff from
time to time. Contrary to expectations their sales were up 35% on last year
so I'd better get going.

--
Michael Koblic
Campbell River, BC

Jim Wilkins wrote:

You can check if the tool will shave off a fraction of a thousandth
while you're still a few thousandths out and can safely remove and
hone it.

Presumably this is possible only with a QCTP without removing the toolbit
from the holder? If you took it out of a lantern or a rocker you will never
be able to re-insert it in exactly the same way. Or am I missing something?

When I have difficulty with a fit I make the start of the bore or the
shaft slightly tapered by filing or cutting steps, press the parts
together enough to make marks, then cut down to almost remove those
marks. Candle flame soot or marker ink makes them easier to see.

OK. I have done something similar with a Sharpie pen but not in this
context. Thanks.

--
Michael Koblic
Campbell River, BC

On 2009-07-10, Michael Koblic wrote:
DoN. Nichols wrote:

[ ... ]

Chacun a son gout...

After all -- I don't have to worry about the usual virus
infections with the Sun Workstation. They are all targeted at the
easiest target -- Windows. :-)

Yes. Mine has caught the swine flu I think.

What kind of spam does that send out? (Well ... spam is a pork
product, after all. :-)

[ ... ]

O.K. If you are considering purchasing a larger lathe (as
suggested by the questions about lubrication), yes it is more than you
need to do.

It is all about understanding the options and then making the right choice.
The one big unknown is the future performance of the RedNeck beast. I made a
toolpost for it (well, a boring bar holder really) and it will be ready to
go tomorrow. If it does half a decent job the pressure is off.

O.K. Good Luck there.

[...]

Well, it is a close run thing between using the telescopic gauge and
a micrometer and actually making something with the required
accuracy. The last two attempts at making something to a given
dimension I overshot by
0.010" and 0.004" respectively. I suppose I am getting better...

Hmm ... first trick is to make sure that the tool is quite
sharp.

As well as the operator.

Second is to feed something like 1/3 the distance to reach final
diameter, make your cut, and measure what you really got, comparing it
to what you expected. Divide what is left by two, and adjust by how
far off your previous result was. Feed in that much, and make
another cut and measure again. Adjust again for the final cut.

It is difficult to get a very light cut to produce what you
want, because deflection of the workpiece and the tool may prevent
ever taking a bite, so when you finally feed enough to take another
bite, it is too big. So sneaking up on the final dimension can be
difficult, and making larger cuts works better.

I am still struggling to understand fully what happens if you run the tool
over the workpiece in two or three passes without adjusting the feed at all.

Well ... a mill may smooth out the previous cuts, and perhaps
trim off chips which were pressure welded by the previous cut if you
don't use a shop vac or some other flow of air to remove chips from the
work zone.

With a lathe, it will depend in part on the workpiece material,
and in part on the true sharpness of the tool. Carbides tend to not be
very sharp -- though there can be exceptions. And coated carbides are
particularly dull, but are very good at removing lots of metal fast with
a powerful enough lathe. Ideally, you should use the carbide for the
roughing, and switch to well honed HSS for the finish cuts -- but the
problem is that you don't know just how deep a cut the HSS will take
that first pass after the change.

This applies to both the mill and the lathe. In both cases it was the
finishing cut that took me past the specified dimension.

In part, it is spring in both the machine and the workpiece.
You need the workpiece rigidly attached to the milling bed for milling,
which may mean a good rigid milling vise (the vises which let you tilt
the vise relative to the bed are particularly poor in this respect, and
those with a swivel base introduce more give into the holding of the
workpiece too. The column on your milling machine is not that rigid,
and I don't know about the head of the milling machine.

If the milling cutter is dull, it will just skate over the
surface of the workpiece without removing any material until you give it
too much feed, at which point it will take too much material.

For a lathe, the first thing is the workpiece needs proper
support, and if it is sticking out beyond the chuck anywhere beyond four
times the diameter, it needs a live center to support the end.

Also -- the stack-up of compound, cross slide, and carriage all
introduce a bit of give.

And if the edge of the tool is above the centerline, it will be
applying a lot more pressure before it starts to cut.

As for getting the boring to work right -- bore to a few
thousandths undersized, and then use a reamer to get to final size.
The same problems with sneaking up on the size occur when boring as
when turning -- perhaps more so.

I guess this is OK up to about 1/2". Economy-wise.

Or one reamer just for the size you need, not a full set.

Talking about economy: I went to visit the shop that sells my stuff from
time to time. Contrary to expectations their sales were up 35% on last year
so I'd better get going.

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 ---

On 2009-07-10, Michael Koblic wrote:
Jim Wilkins wrote:

You can check if the tool will shave off a fraction of a thousandth
while you're still a few thousandths out and can safely remove and
hone it.

Presumably this is possible only with a QCTP without removing the toolbit
from the holder? If you took it out of a lantern or a rocker you will never
be able to re-insert it in exactly the same way. Or am I missing something?

If you hone it, you will need to re-set it anyway. The honing
will change the dimensions at least somewhat. This is where carbide
inserts are nice -- if you can find a sharp enough one to start with,
which is a problem. You take the tool holder (with a QCTP) out, loosen
the screw securing the insert, rotate it to a fresh sharp corner,
reclamp and replace. This makes the change without changing the
dimensions.

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 ---

On Jul 10, 12:04*am, "DoN. Nichols" wrote:
On 2009-07-10, Michael Koblic wrote:

Jim Wilkins wrote:

You can check if the tool will shave off a fraction of a thousandth
while you're still a few thousandths out and can safely remove and
hone it.

Presumably this is possible only with a QCTP without removing the toolbit
from the holder? If you took it out of a lantern or a rocker you will never
be able to re-insert it in exactly the same way. Or am I missing something?

* * * * If you hone it, you will need to re-set it anyway. *The honing
will change the dimensions at least somewhat. This is where carbide
inserts are nice -- if you can find a sharp enough one to start with,
which is a problem. *You take the tool holder (with a QCTP) out, loosen
the screw securing the insert, rotate it to a fresh sharp corner,
reclamp and replace. *This makes the change without changing the
dimensions.

* * * * Good Luck,
* * * * * * * * DoN.

Grinding or honing the bit moves the edge away from the cut. You would
have to reset it if you were making multiple parts but not when
sneaking up on the finish dimension of the first or only one, after
roughing them all.

jsw

On Jul 9, 8:37*pm, "Michael Koblic" wrote:
Jim Wilkins wrote:
You can check if the tool will shave off a fraction of a thousandth
while you're still a few thousandths out and can safely remove and
hone it.

Presumably this is possible only with a QCTP without removing the toolbit
from the holder? If you took it out of a lantern or a rocker you will never
be able to re-insert it in exactly the same way. Or am I missing something?
....
Michael Koblic
Campbell River, BC

You don't have to reinsert it exactly the same way, you remove and
sharpen the bit while there is still enough extra metal left to take a
fine trial cut and measure.

jsw

"DoN. Nichols" wrote in message
...

After all -- I don't have to worry about the usual virus
infections with the Sun Workstation. They are all targeted at the
easiest target -- Windows. :-)

Yes. Mine has caught the swine flu I think.

What kind of spam does that send out? (Well ... spam is a pork
product, after all. :-)

It does not. Occasionally it makes pig's breakfast of things in general.

[ ... ]

O.K. If you are considering purchasing a larger lathe (as
suggested by the questions about lubrication), yes it is more than you
need to do.

It is all about understanding the options and then making the right
choice.
The one big unknown is the future performance of the RedNeck beast. I
made a
toolpost for it (well, a boring bar holder really) and it will be ready
to
go tomorrow. If it does half a decent job the pressure is off.

O.K. Good Luck there.

I have struggeled all afternon with trying to get the chuck and face plate
turn true. I have reduced the wobble to about 0.012" which is realistically
the limit of my ability and the dead-blow hammer. For allI know the thread
on the 1" bolt ("the spindle) has not been cut true. Fancy that! I checked
both the chuck and the face plate lying on their collars and they seem OK.

OTOH mounting the vise in lieu of a cross-slide I was able to achieve less
than 0.001" parallelism (which will presumably last till the next rainy
day).

The biggest disappointment was finding out that if I want to use this vise
as a cross-slide the swing will be reduced to mere 8".


[...]


I guess this is OK up to about 1/2". Economy-wise.

Or one reamer just for the size you need, not a full set.

I have adopted the policy of buying them one at a time depending on the job
at hand. But when they get to 1/2" they start getting quite expensive.


--
Michael Koblic
Campbell River, BC

Jim Wilkins wrote:
On Jul 9, 8:37 pm, "Michael Koblic" wrote:
Jim Wilkins wrote:
You can check if the tool will shave off a fraction of a thousandth
while you're still a few thousandths out and can safely remove and
hone it.

Presumably this is possible only with a QCTP without removing the
toolbit from the holder? If you took it out of a lantern or a rocker
you will never be able to re-insert it in exactly the same way. Or
am I missing something? ... Michael Koblic
Campbell River, BC

You don't have to reinsert it exactly the same way, you remove and
sharpen the bit while there is still enough extra metal left to take a
fine trial cut and measure.


I see.

One of the things I was not fully aware of is that if one does three passes
with the same (sharp) tool over the same area without changing anything, the
first pass produces sort of peaks and valleys. The second pass will not
follow the path of the first pass exactly and will flatten these peaks. The
third pass will do so even more especially if done at higher speed. Thus the
first measurment would catch the peaks which will not be there after the
second and third pass and the measurment will be less.

I assume this is true even in a perfectly rigid system with an infinitely
sharp tool. Thus the trick is to find out how much the tool will remove
between the first and third pass. Was this what you were referring to in
your first response?

--
Michael Koblic
Campbell River, BC

On 2009-07-11, Michael Koblic wrote:

"DoN. Nichols" wrote in message
...

[ ... ]

O.K. If you are considering purchasing a larger lathe (as
suggested by the questions about lubrication), yes it is more than you
need to do.

It is all about understanding the options and then making the right
choice.
The one big unknown is the future performance of the RedNeck beast. I
made a
toolpost for it (well, a boring bar holder really) and it will be ready
to
go tomorrow. If it does half a decent job the pressure is off.

O.K. Good Luck there.

I have struggeled all afternon with trying to get the chuck and face plate
turn true. I have reduced the wobble to about 0.012" which is realistically
the limit of my ability and the dead-blow hammer. For allI know the thread
on the 1" bolt ("the spindle) has not been cut true.

The threads on a typical bolt are not *cut* at all -- they are
*rolled*. Sort of like three-roller knurling, except that there are
thread formed in the rollers, and I believe that they are geared
together so they form a complete thread instead of three partial threads
out of sync with each other. :-) Parallel to the axis of the bolt is not
considered an important factor. If you want parallel, you'll have to
turn the threads on a plain steel shaft, or maybe use allthread after
discarding the end couple of inches to be sure that things are well
positioned. Drill and internally thread bushings to fit the bearings,
Loctite them in place, and then turn them true to the axis of the
allthread.

Fancy that! I checked
both the chuck and the face plate lying on their collars and they seem OK.

O.K. but the real test is with a turned thread in the same
bearings which held the shaft while it was being threaded.

OTOH mounting the vise in lieu of a cross-slide I was able to achieve less
than 0.001" parallelism (which will presumably last till the next rainy
day).

Oh yes -- you've got wood as part of it, don't you.

The biggest disappointment was finding out that if I want to use this vise
as a cross-slide the swing will be reduced to mere 8".

This is a vise on a slide with a leadscrew? Maybe two at
something approximating right angles? I'll bet that there is not enough
rigidity on that, either.

[ ... reamers ... ]

I guess this is OK up to about 1/2". Economy-wise.

Or one reamer just for the size you need, not a full set.

I have adopted the policy of buying them one at a time depending on the job
at hand. But when they get to 1/2" they start getting quite expensive.

Have you checked eBay? IIRC, the diameter which you were
looking for was 5/8". Check out these auctions:

300321263442

250460980926

170316404632

180379269150

270422638488

120408982014

400027644383

390067078707

390067071101

390066837988

120431725903

3837402768 (yes, this does appear to be the number)

320284520680

and quite a few more. I skipped over the adjustable expansion
reamers and the tapered reamers, along with a few others which I felt
would be unsuitable.

My search string was:

reamers 5/8"

and the prices go from about $2.95 up. Some of the lots offer extra
reamers in addition to the 5/8" which you want. There are both hand
reamers (square end for holding in a tap wrench) and chucking reamers
(for use under power).

So -- you can pick up what you need on eBay for much more
reasonable prices than from a new vendor.

I've picked up from eBay sets of reamers covering a fairly wide
size range.

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 ---

On 2009-07-11, Michael Koblic wrote:
Jim Wilkins wrote:
On Jul 9, 8:37 pm, "Michael Koblic" wrote:
Jim Wilkins wrote:
You can check if the tool will shave off a fraction of a thousandth
while you're still a few thousandths out and can safely remove and
hone it.

Presumably this is possible only with a QCTP without removing the
toolbit from the holder? If you took it out of a lantern or a rocker
you will never be able to re-insert it in exactly the same way. Or
am I missing something? ... Michael Koblic
Campbell River, BC

You don't have to reinsert it exactly the same way, you remove and
sharpen the bit while there is still enough extra metal left to take a
fine trial cut and measure.


I see.

One of the things I was not fully aware of is that if one does three passes
with the same (sharp) tool over the same area without changing anything, the
first pass produces sort of peaks and valleys. The second pass will not
follow the path of the first pass exactly and will flatten these peaks. The
third pass will do so even more especially if done at higher speed. Thus the
first measurment would catch the peaks which will not be there after the
second and third pass and the measurment will be less.

I assume this is true even in a perfectly rigid system with an infinitely
sharp tool.

That depends. If the feed is coming through the carriage drive
or hand fed, yes it will pretty much improve things -- if the tool nose
is too much of a point for the feed. If you have a sharp tool point, go
for a finer feed. If you need a faster feed, round the point somewhat.

But -- if your feed comes from the leadscrew and half nuts (not
present on your Taig, so that does not matter) then it will take
precisely the same path and not cut the peaks left by a previous pass,
but rather move through the existing valley. Your experience with the
Taig involves hand feeding of the carriage by necessity. There is no
other option present, so the path of the tool is going to be somewhat
unpredictable no matter how closely you attempt to feed at precisely the
same rate.

Note that some of the less expensive lathes do not have a
separate carriage feed in addition to the leadscrew and half nuts (which
*should* be reserved for threading, not turning to minimize wear on the
leadscrew and half nuts which can reduce the precision of subsequent
threading. An example of this is my ancient Atlas/Craftsman 6x18"
lathe.

Thus the trick is to find out how much the tool will remove
between the first and third pass. Was this what you were referring to in
your first response?

I believe that he is assuming a slow enough feed for the
geometry of the tool tip, and is assuming that you are adding a little
more infeed for each pass -- especially for the next to last pass (just
after honing the tool) and the last pass (also with the freshly honed
tool).

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 ---

On Jul 10, 8:58*pm, "Michael Koblic" wrote:
Jim Wilkins wrote:
[fine cuts]

....The second pass will not
follow the path of the first pass exactly ...
I assume this is true even in a perfectly rigid system with an infinitely
sharp tool. Thus the trick is to find out how much the tool will remove
between the first and third pass. Was this what you were referring to in
your first response?

Michael Koblic

I see the same effect but the reduction in diameter is well under a
thousandth.

My 1965 lathe is very far from perfectly rigid. I haven't turned
anything critical since I ground the wear off the bottom of the
compound. Previously the compound was loose in the middle of its
travel and jammed near the ends. In that state carbide often chipped
and repeated passes removed fine chips randomly and changed the
surface finish, using either manual or automatic feed. I thought the
patterning came from wear in the feed gears.

I usually get the most even finish when the bit takes off a fairly
thick chip at a slow automatic feed rate. I think the greater cutting
force removes all play from worn, roughened bearing surfaces. However
I can't control the diameter as closely as when alternately measuring
and shaving off most of the difference.

The old books recommend a wide tool and fairly coarse feed for
finishing. Apparently the long contact line stabilizes and guides the
cutting edge. On my lathe a narrow point leaves a rough finish even at
the slowest feed rate of 0.00078" per rev.

You could experiment with a slanted cutting edge such as the one back
rake creates on the end of a right-hand turning tool. In my limited
experience it may do a good job if the clearance angle below the edge
is small enough to keep the bit from digging in. I don't know the
proper angle, I try for about 5 degrees and then raise or lower the
bit until it cuts smoothly.

Despite its problems the 10" lathe has served me well. 9" to 12" seems
to be a good size for making machine parts for repairs and
experiments. The controls are light and sensitive enough to make tiny
things like #0-80 screws and it's capable of roughing a few inches of
steel off a bar at a reasonable hobby shop rate. The 15" lathes at
work are considerably less pleasant for delicate tasks. The 6" lathe I
bought first was a mistake.

jsw

Jim Wilkins wrote:

I see the same effect but the reduction in diameter is well under a
thousandth.

My 1965 lathe is very far from perfectly rigid.

The concept of perfect rigidity was used purely to illustrate the point.
Like the concept of an infinitely fat man it does not exist in reality I am
sure.

[...]

The old books recommend a wide tool and fairly coarse feed for
finishing. Apparently the long contact line stabilizes and guides the
cutting edge. On my lathe a narrow point leaves a rough finish even at
the slowest feed rate of 0.00078" per rev.

I think I have to learn to distinguish when to switch to such "finishing
tool". I have had some bad experiences with tools that took too much of the
metal.

You could experiment with a slanted cutting edge such as the one back
rake creates on the end of a right-hand turning tool. In my limited
experience it may do a good job if the clearance angle below the edge
is small enough to keep the bit from digging in. I don't know the
proper angle, I try for about 5 degrees and then raise or lower the
bit until it cuts smoothly.

Now I have a proper grinding set up I can have a go at making all sorts of
different shapes.

Despite its problems the 10" lathe has served me well. 9" to 12" seems
to be a good size for making machine parts for repairs and
experiments. The controls are light and sensitive enough to make tiny
things like #0-80 screws and it's capable of roughing a few inches of
steel off a bar at a reasonable hobby shop rate. The 15" lathes at
work are considerably less pleasant for delicate tasks.

Two days ago I saw a dream - 30" Russian lathe. Slightly bigger than our
living room.

The 6" lathe I bought first was a mistake.

Care to expand on that?

--
Michael Koblic
Campbell River, BC

DoN. Nichols wrote:

[...]

That depends. If the feed is coming through the carriage drive
or hand fed, yes it will pretty much improve things -- if the tool
nose is too much of a point for the feed. If you have a sharp tool
point, go for a finer feed. If you need a faster feed, round the
point somewhat.

But -- if your feed comes from the leadscrew and half nuts (not
present on your Taig, so that does not matter) then it will take
precisely the same path and not cut the peaks left by a previous pass,
but rather move through the existing valley. Your experience with the
Taig involves hand feeding of the carriage by necessity. There is no
other option present, so the path of the tool is going to be somewhat
unpredictable no matter how closely you attempt to feed at precisely
the same rate.

Note that some of the less expensive lathes do not have a
separate carriage feed in addition to the leadscrew and half nuts
(which *should* be reserved for threading, not turning to minimize
wear on the leadscrew and half nuts which can reduce the precision of
subsequent threading. An example of this is my ancient
Atlas/Craftsman 6x18" lathe.

I suspect this is one of those things with a fairly flat learning curve. So
many variables.


--
Michael Koblic
Campbell River, BC

DoN. Nichols wrote:

[ ... ]

I have struggeled all afternon with trying to get the chuck and face
plate turn true. I have reduced the wobble to about 0.012" which is
realistically the limit of my ability and the dead-blow hammer. For
allI know the thread on the 1" bolt ("the spindle) has not been cut
true.

This is a vise on a slide with a leadscrew? Maybe two at
something approximating right angles? I'll bet that there is not
enough rigidity on that, either.

I shall post some pics on flickr when I get it together. I was supposed to
work on it today but thought I would go fencing in AM (we are doing a demo
for kids early next week). As a result my back said 'no' to any further
activity (it was iffy to start with). Maybe tomorrow...

[ ... reamers ... ]

I guess this is OK up to about 1/2". Economy-wise.

Or one reamer just for the size you need, not a full set.

I have adopted the policy of buying them one at a time depending on
the job at hand. But when they get to 1/2" they start getting quite
expensive.

Have you checked eBay? IIRC, the diameter which you were
looking for was 5/8". Check out these auctions:

300321263442

250460980926

170316404632

180379269150

270422638488

120408982014

400027644383

390067078707

390067071101

390066837988

120431725903

3837402768 (yes, this does appear to be the number)

320284520680

and quite a few more. I skipped over the adjustable expansion
reamers and the tapered reamers, along with a few others which I felt
would be unsuitable.

My search string was:

reamers 5/8"

and the prices go from about $2.95 up. Some of the lots offer extra
reamers in addition to the 5/8" which you want. There are both hand
reamers (square end for holding in a tap wrench) and chucking reamers
(for use under power).

So -- you can pick up what you need on eBay for much more
reasonable prices than from a new vendor.

That was a lot of work and I do appreciate it! Sadly a) majority of the
vendors do not ship to Canada and b) those that do charge shipping that
makes the whole deal un-economical. I can get a 5/8" M-2 reamer from KBC for
about Cdn $25 if it becomes necessary. I like their drill-length reamers BTW
which are God-sent in the Taig but they do not go higher than 1/2".

Next week I am off to Vancouver and KBC has been added to the list of "candy
stores".

--
Michael Koblic
Campbell River, BC

On Jul 11, 7:52*pm, "Michael Koblic" wrote:
Jim Wilkins wrote:
...The 6" lathe I bought first was a mistake.

Care to expand on that?
Michael Koblic

The 6" Sears / AA lathe's 1/2"-20 spindle isn't stiff enough to turn
steel. When I got it I only intended to make small aluminum and brass
parts for electronics, but then I bought a wood bandsaw that needed a
new lower shaft and discovered that the lathe couldn't handle the job.
If everything went well it cut the steel, however if the bit dug in
from too large a cut, meaning about 0.010" deep, the whole lathe would
twist and I'd have to pound the bent spindle straight again. The fix
is said to be a 3/4" spindle nose like your Taig's. Maybe someday I'll
finish the new spindle I started and bore out the headstock. It isn't
a priority, the small lathe spins faster for polishing but otherwise
doesn't do anything the South Bend can't do better, including make
very small parts.

At MITRE I had a copy of the small Prazi in my lab. Again it was good
enough for electronics or probably small engine models, and stiffer
than the Sears, but someone before me had stripped the plastic feed
gears trying to turn steel on it. It's main fault was the lack of half
nuts, I had to crank the damn feed screw to move the carriage.

Lathes basically make power transmission components. A small one can
do shafts and bushings but not gears and pulleys large enough to
transmit more than muscle power. I think you are beginning to see how
much of a limitation that is.

The jobs that push the capacity of my machines are mostly large wheels
and pulleys, unplanned repairs, and special tools rather than the
small stuff I originally bought them for. The money spent on machinery
has come back as a front end loader and a sawmill nearly for free,
also the abilities repair for $5 instead of replace for $500, to own
things I can't buy and to strengthen the weak failure points of the
current value-engineered commercial products. Often these are plastic
pivots that I replace with stainless steel TIG rod, turned down to fit
and threaded for retaining nuts.

jsw