Putting oil on some salad bowls for the first sale in a couple of weeks,
when, horrors! Down in the transition from wall to bottom, half-hidden in
the annual rings, was a heel mark. You know, the ones where the back of the
bevel burnished its way around while you were concentrating on the front.

Not a problem. Went back to the lathe, chucked the bowl in the recess and
hit the entire inside with 150/220/320. As I applied the fresh oil with my
3M synthetic wool, I noticed how the segment was now a match for its
surroundings. No low spots, either, since I was able to sand with the piece
rotating.

Sure do love the forethought....

On Mon, 13 Jun 2005 08:31:59 -0400, "George" wrote:

Putting oil on some salad bowls for the first sale in a couple of weeks,
when, horrors! Down in the transition from wall to bottom, half-hidden in
the annual rings, was a heel mark. You know, the ones where the back of the
bevel burnished its way around while you were concentrating on the front.

Not a problem. Went back to the lathe, chucked the bowl in the recess and
hit the entire inside with 150/220/320. As I applied the fresh oil with my
3M synthetic wool, I noticed how the segment was now a match for its
surroundings. No low spots, either, since I was able to sand with the piece
rotating.

Sure do love the forethought....

that sounds like a justification for a vacuum chuck system, george... remember,
you can't take it with you and there's no use leaving anything for the kids to
fight over.. *g*



mac

Please remove splinters before emailing

"mac davis" wrote in message
news
On Mon, 13 Jun 2005 08:31:59 -0400, "George" wrote:

Putting oil on some salad bowls for the first sale in a couple of weeks,
when, horrors! Down in the transition from wall to bottom, half-hidden
in
the annual rings, was a heel mark. You know, the ones where the back of
the
bevel burnished its way around while you were concentrating on the front.

Not a problem. Went back to the lathe, chucked the bowl in the recess
and
hit the entire inside with 150/220/320. As I applied the fresh oil with
my
3M synthetic wool, I noticed how the segment was now a match for its
surroundings. No low spots, either, since I was able to sand with the
piece
rotating.

Sure do love the forethought....

that sounds like a justification for a vacuum chuck system, george...
remember,
you can't take it with you and there's no use leaving anything for the
kids to
fight over.. *g*


The NOVA has a built-in capability, but somehow I think a vacuum chuck on a
2" recess isn't going to instill confidence in the guy working a 12" bowl.

Hi George

Tailstock brought up with a soft pussy foot to keep the bowl in place
and ugly or no recess would make for NO problem, resurfacing inside and
also outside heel marks, and a vacuum chuck if used with a proper sized
vacuum drum chuck also would fit the bill.

Have fun and take care
Leo Van Der Loo

George wrote:

The NOVA has a built-in capability, but somehow I think a vacuum chuck on a
2" recess isn't going to instill confidence in the guy working a 12" bowl.

On Mon, 13 Jun 2005 12:10:38 -0400, "George" wrote:


"mac davis" wrote in message
news
On Mon, 13 Jun 2005 08:31:59 -0400, "George" wrote:

Putting oil on some salad bowls for the first sale in a couple of weeks,
when, horrors! Down in the transition from wall to bottom, half-hidden
in
the annual rings, was a heel mark. You know, the ones where the back of
the
bevel burnished its way around while you were concentrating on the front.

Not a problem. Went back to the lathe, chucked the bowl in the recess
and
hit the entire inside with 150/220/320. As I applied the fresh oil with
my
3M synthetic wool, I noticed how the segment was now a match for its
surroundings. No low spots, either, since I was able to sand with the
piece
rotating.

Sure do love the forethought....

that sounds like a justification for a vacuum chuck system, george...
remember,
you can't take it with you and there's no use leaving anything for the
kids to
fight over.. *g*


The NOVA has a built-in capability, but somehow I think a vacuum chuck on a
2" recess isn't going to instill confidence in the guy working a 12" bowl.

yabut....
if you had a vacuum system, you wouldn't be drilling holes in the bottoms,
right??
(I am probably wrong.. when I saw the cost of vac, I quit learning about it)


mac

Please remove splinters before emailing

"mac davis" wrote in message
...
On Mon, 13 Jun 2005 12:10:38 -0400, "George" wrote:

yabut....
if you had a vacuum system, you wouldn't be drilling holes in the bottoms,
right??
(I am probably wrong.. when I saw the cost of vac, I quit learning about
it)


No, the vacuum chuck is used for light work only. As Leo mentioned, if I
made a huge cup to set the rear of the bowl in, then played to get it
centered, then had enough of a pump to maintain a suitable vacuum through
that much thin end grain....

Well, you get the point.

Fortunately, I don't have to take such extraordinary measures. What Leo
thinks is ugly without ever having seen it held the bowl perfectly, and was
not damaged at all in the process. Not to mention, it was prepared and
sanded before the bowl was reversed to hollow, so no third mount was ever
necessary!

"mac davis" wrote in message
...
On Mon, 13 Jun 2005 12:10:38 -0400, "George" wrote:


"mac davis" wrote in message
news
On Mon, 13 Jun 2005 08:31:59 -0400, "George" wrote:
snip

(I am probably wrong.. when I saw the cost of vac, I quit learning about
it)


mac

Please remove splinters before emailing

If you do a bit of researching on the net you will see that you can make a
vac chucking system with very little cost. Use an old freezer compressor for
the vacuum and make a rotating joint with some sealed bearings - the ease of
the rotating joint manufacture depends on what kind of outboard spindle
arrangement you have.
I used an old 2 piston rather large refrigeration compressor but bought a
Oneway rotating joint. I made my own drum chucks out of ABS pipe connectors.
Billh

On Tue, 14 Jun 2005 06:37:51 -0400, "George" wrote:


"mac davis" wrote in message
.. .
On Mon, 13 Jun 2005 12:10:38 -0400, "George" wrote:

yabut....
if you had a vacuum system, you wouldn't be drilling holes in the bottoms,
right??
(I am probably wrong.. when I saw the cost of vac, I quit learning about
it)


No, the vacuum chuck is used for light work only. As Leo mentioned, if I
made a huge cup to set the rear of the bowl in, then played to get it
centered, then had enough of a pump to maintain a suitable vacuum through
that much thin end grain....

Well, you get the point.

Fortunately, I don't have to take such extraordinary measures. What Leo
thinks is ugly without ever having seen it held the bowl perfectly, and was
not damaged at all in the process. Not to mention, it was prepared and
sanded before the bowl was reversed to hollow, so no third mount was ever
necessary!


hmm... maybe it's just tool envy, but vacuum chucking sounds like a PITA..


mac

Please remove splinters before emailing

Hi George

I will insert a few words so as to not give the impression that I "find
your recess ugly without seeing it"

Beautiful- Pretty - Ugly or NO Recess it would make NO PROBLEM, to do
both inside and outside of a bowl turning where you had sanded but not
noticed the heel pressure mark or other imperfections that make us go
back and try to improve upon, be that just some scratch marks or crushed
grain.
The point of all this is that "there are more ways to skin a cat" as
they say, or yes there are many good ways to hold, turn or otherwise
change the shape of a chunk of wood, besides the way you have shown us,
and the ways others have used and are using, just be careful you don't
get hurt doing it.


http://homepage.mac.com/l.vanderloo/PhotoAlbum26.html

Have fun and take care
Leo Van Der Loo


George wrote:/snip/

Fortunately, I don't have to take such extraordinary measures.

What Leo
thinks is ugly without ever having seen it held the bowl perfectly,

and was
not damaged at all in the process. Not to mention, it was prepared and
sanded before the bowl was reversed to hollow, so no third mount was ever
necessary!

Hi Mack

You might be living on a low budget, but a vacuum system is easily build
by anyone with very few tools or dollars,

You might have seen the one that I made, it's on my site, I happened to
have a small compressor, but you can use other setups, car ac units, big
old freezer compressors or old truck refrigeration unit compressors, etc.
A couple of sealed bearings and turned plug to go into you headstock
shaft and a hose barb or two, bleeder valve and some plastic hose and
open cell foam for filtering, and some time to stick it all together,
there are some plans on the net if you do need help visualizing it.


http://homepage.mac.com/l.vanderloo/PhotoAlbum25.html

Have fun and take care
Leo Van Der Loo

mac davis wrote:

(I am probably wrong.. when I saw the cost of vac, I quit learning about it)


mac

Please remove splinters before emailing

"mac davis" wrote in message
...
On Mon, 13 Jun 2005 12:10:38 -0400, "George" wrote:
SNIP .......
if you had a vacuum system, you wouldn't be drilling holes in the bottoms,
right??
(I am probably wrong.. when I saw the cost of vac, I quit learning about
it)
====================
Mac,
Check out the older automotive wrecking yards in your area. One of the old
York style (60's-70's) auto air conditioner V-twin compressors will make a
good vacuum system. (Later ones will probably do OK, but I haven't seen one
of those) Make a bracket to mount it on a piece of plywood, along with a 1/4
HP 1750 RPM electric motor to turn it just above idle speed for the car it
came from. Some vacuum line and parts from your local auto parts place and a
some skate board bearings to make your rotary connector, and you're ready
for vacuum chucking. Doesn't have to be expensive at all.

Ken Moon
Webberville, TX.

"Ken Moon" wrote in message
ink.net...
Check out the older automotive wrecking yards in your area. One of the old
York style (60's-70's) auto air conditioner V-twin compressors will make a
good vacuum system. (Later ones will probably do OK, but I haven't seen
one
of those) Make a bracket to mount it on a piece of plywood, along with a
1/4
HP 1750 RPM electric motor to turn it just above idle speed for the car it
came from. Some vacuum line and parts from your local auto parts place and
a
some skate board bearings to make your rotary connector, and you're ready
for vacuum chucking. Doesn't have to be expensive at all.

For those contemplating salvage systems, remember that Freon was its own
lubricant, so you'll have to provide some or seize the system. Hopefully
not while you've got something hanging up there that could smack you.

On Tue, 14 Jun 2005 14:03:28 -0400, Leo Van Der Loo
wrote:

Hi Mack

You might be living on a low budget, but a vacuum system is easily build
by anyone with very few tools or dollars,

You might have seen the one that I made, it's on my site, I happened to
have a small compressor, but you can use other setups, car ac units, big
old freezer compressors or old truck refrigeration unit compressors, etc.
A couple of sealed bearings and turned plug to go into you headstock
shaft and a hose barb or two, bleeder valve and some plastic hose and
open cell foam for filtering, and some time to stick it all together,
there are some plans on the net if you do need help visualizing it.


http://homepage.mac.com/l.vanderloo/PhotoAlbum25.html

Have fun and take care
Leo Van Der Loo

Well Leo.. it's tempting, BUT... *g*

Just got the new lathe, (2nd one since November), several new chisels and
scrapers, new chain saw.... and my coring system should get here tomorrow... (on
our anniversary, just for weirdness)
I think my budget and learning curve are both going to be too busy catching up
for any new stuff for a bit.. *g*


mac

Please remove splinters before emailing

On Wed, 15 Jun 2005 06:01:18 -0400, "George" wrote:


"Ken Moon" wrote in message
link.net...
Check out the older automotive wrecking yards in your area. One of the old
York style (60's-70's) auto air conditioner V-twin compressors will make a
good vacuum system. (Later ones will probably do OK, but I haven't seen
one
of those) Make a bracket to mount it on a piece of plywood, along with a
1/4
HP 1750 RPM electric motor to turn it just above idle speed for the car it
came from. Some vacuum line and parts from your local auto parts place and
a
some skate board bearings to make your rotary connector, and you're ready
for vacuum chucking. Doesn't have to be expensive at all.

For those contemplating salvage systems, remember that Freon was its own
lubricant, so you'll have to provide some or seize the system. Hopefully
not while you've got something hanging up there that could smack you.

good point.. and (at least in Calif.) you can't buy freon any more...

I was actually thinking that if I used my Harbor Freight compressor for the
vacuum system, I could shop for a new (and quieter) compressor... *g*


mac

Please remove splinters before emailing

If you do a bit of researching on the net you will see that you can make a
vac chucking system with very little cost. Use an old freezer compressor
for
the vacuum and make a rotating joint with some sealed bearings - the ease
of
the rotating joint manufacture depends on what kind of outboard spindle
arrangement you have.
I used an old 2 piston rather large refrigeration compressor but bought a
Oneway rotating joint. I made my own drum chucks out of ABS pipe
connectors.
Billh

For vacuum, high air-flow is better than high pressure. A household vauum
cleaner is sufficient, provided it has a by-pass valve to stop the vac motor
from burning out from lack of airflow.

Depending on the lathe, a rotation joint is not necessary. A tin can can do
the job! Mine is sized to fit over the handweel and secured to the
headstock with a disk of 1/2" ply, cut in half and drilled to fit closely
around the spindle. Oiling the spindle then applying a bead of silastic
around where the ply joins the spindle seals it enough for the vacuum to
work. (It's highflow, not high-pressure, remember.) A hole cut in the
other tin-can for the hose from the vac and voila!

It generates sufficient pressure to do light touch ups to the foot of a
bowl, careful removal of the tenon, reshaping, etc.

Even a commercial vac-chuck set up won't allow more than a light touchup and
a tin can's a darn sight cheaper...

- Andy

Hi Mac

I'm glad to hear you won't be sitting idle, after your anniversary.

HAPPY ANNIVERSARY MAC

Have fun and take care, for many more of the above.
Leo Van Der Loo

mac davis wrote:

Well Leo.. it's tempting, BUT... *g*

Just got the new lathe, (2nd one since November), several new chisels and
scrapers, new chain saw.... and my coring system should get here tomorrow... (on
our anniversary, just for weirdness)
I think my budget and learning curve are both going to be too busy catching up
for any new stuff for a bit.. *g*


mac

Please remove splinters before emailing

"Andy McArdle" wrote in message
u...
If you do a bit of researching on the net you will see that you can make
a
vac chucking system with very little cost. Use an old freezer compressor
for
the vacuum and make a rotating joint with some sealed bearings - the ease
of
the rotating joint manufacture depends on what kind of outboard spindle
arrangement you have.
I used an old 2 piston rather large refrigeration compressor but bought
a
Oneway rotating joint. I made my own drum chucks out of ABS pipe
connectors.
Billh

For vacuum, high air-flow is better than high pressure. A household vauum
cleaner is sufficient, provided it has a by-pass valve to stop the vac
motor
from burning out from lack of airflow.

Depending on the lathe, a rotation joint is not necessary. A tin can can
do
the job! Mine is sized to fit over the handweel and secured to the
headstock with a disk of 1/2" ply, cut in half and drilled to fit closely
around the spindle. Oiling the spindle then applying a bead of silastic
around where the ply joins the spindle seals it enough for the vacuum to
work. (It's highflow, not high-pressure, remember.) A hole cut in the
other tin-can for the hose from the vac and voila!

It generates sufficient pressure to do light touch ups to the foot of a
bowl, careful removal of the tenon, reshaping, etc.

Even a commercial vac-chuck set up won't allow more than a light touchup
and
a tin can's a darn sight cheaper...

- Andy


I think the force holding the bowl onto the drum chuck or faceplate is
approximated by 0.5Xvacuum in inches of mercuryXarea of workpiece under
vacuum. For large diameter pieces this can be a very large number and can
implode/crack the workpiece if it is thin. If the diameter of the bowl is
around 6" or larger under a good vacuum you can do a lot more than just
light touchup cuts.
billh

"George" wrote in message
...

"Ken Moon" wrote in message
ink.net...
Check out the older automotive wrecking yards in your area. One of the
old
York style (60's-70's) auto air conditioner V-twin compressors will make
a
good vacuum system. (Later ones will probably do OK, but I haven't seen
one
of those) Make a bracket to mount it on a piece of plywood, along with a
1/4
HP 1750 RPM electric motor to turn it just above idle speed for the car
it
came from. Some vacuum line and parts from your local auto parts place
and
a
some skate board bearings to make your rotary connector, and you're ready
for vacuum chucking. Doesn't have to be expensive at all.

For those contemplating salvage systems, remember that Freon was its own
lubricant, so you'll have to provide some or seize the system. Hopefully
not while you've got something hanging up there that could smack you.
============================
George,
The older York compresors had an oil sump. The oil has a look similar to
hydraulic fluid. I saw a demo of one that had been in use for several years
with no lubricant problems.

Ken Moon
Webberville, TX.

[snip]
It generates sufficient pressure to do light touch ups to the foot of a
bowl, careful removal of the tenon, reshaping, etc.

Even a commercial vac-chuck set up won't allow more than a light touchup
and
a tin can's a darn sight cheaper...

- Andy


I think the force holding the bowl onto the drum chuck or faceplate is
approximated by 0.5Xvacuum in inches of mercuryXarea of workpiece under
vacuum. For large diameter pieces this can be a very large number and can
implode/crack the workpiece if it is thin. If the diameter of the bowl is
around 6" or larger under a good vacuum you can do a lot more than just
light touchup cuts.
billh

With my setup the smallest dia I can safely hold is around 8-9", but your
formula suggests I should be able to safely hold larger pieces before
needing to worry about cracking. I haven't tried it with anything over 18"
dia so I can't speak from experience.

The only commercial systems I've tried are the Vicmarc & Nova units (newly
set up on friends' lathes) with about 12" bowls and I could still only do
light touch-ups but that could easily be due to incorrect setup. You know,
the "Oooer! A new toy... let's whack it on the lathe and see what we can
do. We'll RTFM later." type attitude. G

Regardless of the system used, including a pressure gauge & adjustable
by-pass valve would, I think, increase the versatility but this is something
else I haven't tried. Yet.

- Andy

"Ken Moon" wrote in message
ink.net...

For those contemplating salvage systems, remember that Freon was its own
lubricant, so you'll have to provide some or seize the system.
Hopefully
not while you've got something hanging up there that could smack you.
============================
George,
The older York compresors had an oil sump. The oil has a look similar to
hydraulic fluid. I saw a demo of one that had been in use for several
years
with no lubricant problems.


Certainly, but it _is_ the exception, isn't it?

"Andy McArdle" wrote in message
u...
[snip]
It generates sufficient pressure to do light touch ups to the foot of a
bowl, careful removal of the tenon, reshaping, etc.

Even a commercial vac-chuck set up won't allow more than a light
touchup
and
a tin can's a darn sight cheaper...

- Andy


I think the force holding the bowl onto the drum chuck or faceplate is
approximated by 0.5Xvacuum in inches of mercuryXarea of workpiece under
vacuum. For large diameter pieces this can be a very large number and can
implode/crack the workpiece if it is thin. If the diameter of the bowl is
around 6" or larger under a good vacuum you can do a lot more than just
light touchup cuts.
billh

With my setup the smallest dia I can safely hold is around 8-9", but your
formula suggests I should be able to safely hold larger pieces before
needing to worry about cracking. I haven't tried it with anything over
18"
dia so I can't speak from experience.

The only commercial systems I've tried are the Vicmarc & Nova units (newly
set up on friends' lathes) with about 12" bowls and I could still only do
light touch-ups but that could easily be due to incorrect setup. You
know,
the "Oooer! A new toy... let's whack it on the lathe and see what we can
do. We'll RTFM later." type attitude. G

Regardless of the system used, including a pressure gauge & adjustable
by-pass valve would, I think, increase the versatility but this is
something
else I haven't tried. Yet.

- Andy


I have a gauge and bleed valve and I wouldn't be without either, especially
the gauge. Without it you are really flying blind and that might let the
piece go flying too! It is surprising how much leakage you can get through
some open-pore wood if it is thin. Another thing to consider is that the
force is pushing the bowl against the faceplate or drum chuck towards the
rear of the spindle. The only force keeping the bowl from sliding
perpendicular to the spindle is the "friction" of the bowl rim against the
faceplate. If the faceplate is covered with foam then the rim "digs in" due
to the force and is held securely. The drum chuck likely has the curvature
of the bowl bottom against the chuck so it keeps it from moving.
Billh

[snip]
I have a gauge and bleed valve and I wouldn't be without either,
especially
the gauge. Without it you are really flying blind and that might let the
piece go flying too! It is surprising how much leakage you can get through
some open-pore wood if it is thin. Another thing to consider is that the
force is pushing the bowl against the faceplate or drum chuck towards the
rear of the spindle. The only force keeping the bowl from sliding
perpendicular to the spindle is the "friction" of the bowl rim against the
faceplate. If the faceplate is covered with foam then the rim "digs in"
due
to the force and is held securely. The drum chuck likely has the curvature
of the bowl bottom against the chuck so it keeps it from moving.
Billh


As you can probabl;y guess, the faceplate for my vac-chuck is home-made too.
A 19mm MDF (fine at lowish speeds) disk screwed to a 6" faceplate and faced
with 5mm foam rubber. The foam itself is fairly porous, but with the high
air-flow that hasn't proved to be a major concern.

I've even made minor catches severe enough to seperate the bowl from the
faceplate and the high air-flow has sucked the bowl back down, albeit
off-centre. Fortunately, apart from when first learning /how/ to use a
vac-chuck, I haven't had any UFOs but I think that's probably because I've
had to learn to use a light touch rather than any inherent advantages of the
chuck.

For the record, I should say that I'm not advocating my system as being "as
good as any other," just that there are some very cheap ways to make a start
for someone with a little ingenuity. Anyone trying it should keep in mind
that you only get what you pay for. G

I am curious about drum chucks though, having never used one. I assume that
they're like jam-fit chucks where it's best to make a custom one for each
job, unless you've already made one that just happens to be the right size?

- Andy

On Wed, 15 Jun 2005 17:17:22 -0400, Leo Van Der Loo
wrote:

Hi Mac

I'm glad to hear you won't be sitting idle, after your anniversary.

HAPPY ANNIVERSARY MAC

Have fun and take care, for many more of the above.
Leo Van Der Loo

Thank you, sir...
this marriage is my 3rd try... hopefully, I've learned enough from the last 2
and won't screw this one up..



mac

Please remove splinters before emailing

snip

I am curious about drum chucks though, having never used one. I assume
that
they're like jam-fit chucks where it's best to make a custom one for each
job, unless you've already made one that just happens to be the right
size?

- Andy



I also use 19mm MDF. Rather than mount it on a faceplate, I drill and tap a
hole in the MDF to directly screw onto my spindle. I then true it up.

You can make a few different sizes of drum chucks. They don't have to be a
tight fit at all just use the largest for the job since you will get more
area and thus holding force.

I use ABS (black sewer pipe) straight connectors which come in several
different diameters. You can also use a short length of the pipe as well. I
make a recess with a parting tool (or whatever you like) such that the
fitting sits in it with a snug fit. It only need be a 1/4" (6 mm) deep or
so. I then epoxy the ABS fitting to the MDF. I then true up the open rim of
the pipe and hot glue on some foam for a gasket and that is all there is to
it. Note that the vacuum force will hold the pipe in the groove in the MDF
so even if the epoxy fails the joint should still hold.

A drum chuck like this is even handy in non-vacuum applications say for
truing a warped external tenon on a dried roughed bowl. Just put on the drum
chuck. Place the bowl over it and bring up the tailstock and true the tenon.
You could even finish the bowl bottom with this method if for some reason it
can't be held under vacuum.

Billh

"George" wrote in message
...

"Ken Moon" wrote in message
ink.net...

For those contemplating salvage systems, remember that Freon was its
own
lubricant, so you'll have to provide some or seize the system.
Hopefully
not while you've got something hanging up there that could smack you.
============================
George,
The older York compresors had an oil sump. The oil has a look similar to
hydraulic fluid. I saw a demo of one that had been in use for several
years
with no lubricant problems.


Certainly, but it _is_ the exception, isn't it?
===============================

Could be, but I don't think so. They needed lubrication just like any other
cylinder/piston assembly. Seems that I do remember him changing oil
periodically. Some racers also used these compressors for tires and air
tools in the pits. They'd mount it on their tow truck either in place of the
normal AC unit or build a separate mounting bracket to mount it below the
block, sort of like some of the newer cars mount their water pumps. They
used a regular automotive paper air filter to clean incoming air, so there
was no lubricant in the airflow.

Ken

"Ken Moon" wrote in message
nk.net...

George,
The older York compresors had an oil sump. The oil has a look similar
to
hydraulic fluid. I saw a demo of one that had been in use for several
years
with no lubricant problems.


Certainly, but it _is_ the exception, isn't it?
===============================

Could be, but I don't think so. They needed lubrication just like any
other
cylinder/piston assembly. Seems that I do remember him changing oil
periodically. Some racers also used these compressors for tires and air
tools in the pits. They'd mount it on their tow truck either in place of
the
normal AC unit or build a separate mounting bracket to mount it below the
block, sort of like some of the newer cars mount their water pumps. They
used a regular automotive paper air filter to clean incoming air, so there
was no lubricant in the airflow.


The modern refrigeration compressor as featured in everything from freezers
to dehumidifiers is not the same.

"billh" wrote in message
. ..

snip

I am curious about drum chucks though, having never used one. I assume
that
they're like jam-fit chucks where it's best to make a custom one for
each
job, unless you've already made one that just happens to be the right
size?

- Andy



I also use 19mm MDF. Rather than mount it on a faceplate, I drill and tap
a
hole in the MDF to directly screw onto my spindle. I then true it up.

I originally tried that but my spindle is threaded past the headstock
casing, so unless I went to the extra effort of finding lock washers, the
MDF'd spin itself in until the edge met the bottom of the casing (it's
tapered back for accessibility) and promptly self-destruct.

You can make a few different sizes of drum chucks. They don't have to be a
tight fit at all just use the largest for the job since you will get more
area and thus holding force.

I use ABS (black sewer pipe) straight connectors which come in several
different diameters. You can also use a short length of the pipe as well.
I
make a recess with a parting tool (or whatever you like) such that the
fitting sits in it with a snug fit. It only need be a 1/4" (6 mm) deep or
so. I then epoxy the ABS fitting to the MDF. I then true up the open rim
of
the pipe and hot glue on some foam for a gasket and that is all there is
to
it. Note that the vacuum force will hold the pipe in the groove in the MDF
so even if the epoxy fails the joint should still hold.

Considering I make many tools/parts myself (having a tiny budget) I'm
surprised I hadn't thought of that. For some reason I've been thinking of
turning them out of scrap wood. Thanks for pointing me in the right
direction.

A drum chuck like this is even handy in non-vacuum applications say for
truing a warped external tenon on a dried roughed bowl. Just put on the
drum
chuck. Place the bowl over it and bring up the tailstock and true the
tenon.
You could even finish the bowl bottom with this method if for some reason
it
can't be held under vacuum.

That gives me a handle on another problem I have at the moment... I've
recently finished turning the foot/tenon off an 8" English Yew bowl with
cole-jaws and in my eagerness to marvel at my accomplishment was careless
enough to clip the edge of the tool-rest which, of course, I hadn't
removed. (I know, I know. You can't say anything I haven't already said to
myself...)

The Yew is a truly lovely piece of birds-eye which had been sitting in a
packing case for many years; it's almost impossible to replace nowadays.
Certainly not on my budget.

Rechucking's out of the question and the foot-print is too small for the
vac-chuck/faceplate. I assume it'd be feasible to mount the base of the
bowl in a drum chuck, bring up the tailstock (padded) and trim the edge that
way?

Just checking for feasibilty from someone who may know before I go
trail-blazing for myself and discover something else I didn't expect.

- Andy

[---8---]
The modern refrigeration compressor as featured in everything from
freezers
to dehumidifiers is not the same.


FWIW, I've asked a few local blokes about their experiences with vacuum
chucking. Most of the blokes who tried it and gave it away as a bad joke
had one thing in common... using a frig compressor. Of the ones with good
experiences only a few used 'em.

There seems to be seperate two reasons why they failed to pass muster:
burning out (I assume it's the lube problem you're talking about) and
although they generate low pressure they're not high enough volume to handle
the inevitable leakage at joints, faceplate or wood pores.

- Andy

Hi Andy

The real problem of burnout with these units is most likely the cooling
that was there with the refrigerant and is no longer there, also no
lubricant does not help but a drop of oil every couple of minutes would
not be to hard to inject on the vacuum side, but the cooling problem is
a hard one.
Of course all the old freezer units had oil baths and those units last
forever, they used a small electric motor and V-belts, I have made a
couple portable compressor setups using a propane cylinder for storage
tank, hooked up to a freezer compressor, they work great.
Reversing this you could have a vacuum tank and vacuum pump, it should
work imo.
Some of those units are likely still to be had at cooling repair places
for the asking or scrap metal prices.

Have fun and take care
Leo Van Der Loo

Andy McArdle wrote:

[---8---]

The modern refrigeration compressor as featured in everything from

freezers

to dehumidifiers is not the same.



FWIW, I've asked a few local blokes about their experiences with vacuum
chucking. Most of the blokes who tried it and gave it away as a bad joke
had one thing in common... using a frig compressor. Of the ones with good
experiences only a few used 'em.

There seems to be seperate two reasons why they failed to pass muster:
burning out (I assume it's the lube problem you're talking about) and
although they generate low pressure they're not high enough volume to handle
the inevitable leakage at joints, faceplate or wood pores.

- Andy

"Andy McArdle" wrote in message
u...
"billh" wrote in message
. ..

snip
snip

That gives me a handle on another problem I have at the moment... I've
recently finished turning the foot/tenon off an 8" English Yew bowl with
cole-jaws and in my eagerness to marvel at my accomplishment was careless
enough to clip the edge of the tool-rest which, of course, I hadn't
removed. (I know, I know. You can't say anything I haven't already said
to
myself...)

The Yew is a truly lovely piece of birds-eye which had been sitting in a
packing case for many years; it's almost impossible to replace nowadays.
Certainly not on my budget.

Rechucking's out of the question and the foot-print is too small for the
vac-chuck/faceplate. I assume it'd be feasible to mount the base of the
bowl in a drum chuck, bring up the tailstock (padded) and trim the edge
that
way?

Just checking for feasibilty from someone who may know before I go
trail-blazing for myself and discover something else I didn't expect.

- Andy


Certainly worth trying and I don't see why it shouldn't work; if I had the
problem it is what I'd do.
Billh

Rechucking's out of the question and the foot-print is too small for the
vac-chuck/faceplate. I assume it'd be feasible to mount the base of the
bowl in a drum chuck, bring up the tailstock (padded) and trim the edge
that
way?

Just checking for feasibilty from someone who may know before I go
trail-blazing for myself and discover something else I didn't expect.

- Andy


Certainly worth trying and I don't see why it shouldn't work; if I had the
problem it is what I'd do.
Billh

I guess the best answer is to gird my loins and try, eh? I can't foresee
any problems either, but only tomorrow will tell...

- Andy

"Andy McArdle" wrote in message
u...
Rechucking's out of the question and the foot-print is too small for
the
vac-chuck/faceplate. I assume it'd be feasible to mount the base of
the
bowl in a drum chuck, bring up the tailstock (padded) and trim the
edge
that
way?

Just checking for feasibilty from someone who may know before I go
trail-blazing for myself and discover something else I didn't expect.

- Andy


Certainly worth trying and I don't see why it shouldn't work; if I had
the
problem it is what I'd do.
Billh

I guess the best answer is to gird my loins and try, eh? I can't foresee
any problems either, but only tomorrow will tell...

For that tailstock bumper, turn a 1x? soft wood circle with tapered edge
large enough to fit inside your bowl. Make sure you have a center mark, and
use to center and contain the piece.

Even neater if you turn a tapered recess for your base on a faceplate with
soft wood. Once it's centered, a tad of hot glue.

For that tailstock bumper, turn a 1x? soft wood circle with tapered edge
large enough to fit inside your bowl. Make sure you have a center mark,
and
use to center and contain the piece.

Even neater if you turn a tapered recess for your base on a faceplate with
soft wood. Once it's centered, a tad of hot glue.

I made myself a drum-chuck and a 2"dia bumper curved to match the bottom of
the bowl. Well... as closely as I could. Then discovered that sometime in
the last week the vacuum hose had a nasty accident and, of course, my duct
tape is nowhere to be found.

After a few moments of reflection I realised that a vacuum wasn't needed;
the drum & tailstock seemed to be holding things quite nicely. I guess I
was concentrating too much on trying what I've read to see what was as plain
as my nose! [sigh]

Long story short, the bowl trimmed nicely although I did have a hairy moment
when first introducing the tool a bit too quickly and it caught in the chip.
The bowl shifted slightly off-centre but no damage was done and everything
turned out for the best. No pun intended. So, I've added yet another
useful method to my repertoire and all is well in my little world.

Thanks for the advice!

- Andy

"Andy McArdle" wrote in message
u...
I made myself a drum-chuck and a 2"dia bumper curved to match the bottom
of
the bowl. Well... as closely as I could.

Long story short, the bowl trimmed nicely although I did have a hairy
moment
when first introducing the tool a bit too quickly and it caught in the
chip.
The bowl shifted slightly off-centre but no damage was done and everything
turned out for the best. No pun intended. So, I've added yet another
useful method to my repertoire and all is well in my little world.

Thus the advantage to centering a bit higher on the bowl with that tapered
circle. Gives you a bit better control over shifting.

Of course, If I had vacuum need and capability, I'd keep a spare roll of
duck tape somewhere handy instead of stored with all those pencils I have
down in the shop....

The bowl shifted slightly off-centre but no damage was done and
everything
turned out for the best. No pun intended. So, I've added yet another
useful method to my repertoire and all is well in my little world.

Thus the advantage to centering a bit higher on the bowl with that tapered
circle. Gives you a bit better control over shifting.

That's why I trounded the base of the bumper to fit, but it appears my logic
was faulty.

Of course, If I had vacuum need and capability, I'd keep a spare roll of
duck tape somewhere handy instead of stored with all those pencils I have
down in the shop....

Duct tape and pencils... the two banes of my life. I have boxes'n'boxes of
both, yet all I have to do is put one down for a second and it disappears,
along with the box it came out of!

I've even gone to the extent of drilling a whole through the end of my
pencil and threading a string to hang around my neck. That didn't work
either; the string kept snagging the odd corner and when I put it down for a
second it /still/ disappeared. [sigh]

- Andy

On Mon, 20 Jun 2005 00:02:09 +1000, "Andy McArdle"
wrote:

The bowl shifted slightly off-centre but no damage was done and
everything
turned out for the best. No pun intended. So, I've added yet another
useful method to my repertoire and all is well in my little world.

Thus the advantage to centering a bit higher on the bowl with that tapered
circle. Gives you a bit better control over shifting.

That's why I trounded the base of the bumper to fit, but it appears my logic
was faulty.

Of course, If I had vacuum need and capability, I'd keep a spare roll of
duck tape somewhere handy instead of stored with all those pencils I have
down in the shop....

Duct tape and pencils... the two banes of my life. I have boxes'n'boxes of
both, yet all I have to do is put one down for a second and it disappears,
along with the box it came out of!

I've even gone to the extent of drilling a whole through the end of my
pencil and threading a string to hang around my neck. That didn't work
either; the string kept snagging the odd corner and when I put it down for a
second it /still/ disappeared. [sigh]

- Andy

Duct tape and pencils go o the same black hole that tape measures and one sock
from each pair go..


mac

Please remove splinters before emailing