I'd like to machine a few (2 or 3) teflon gasket rings out of quarter
inch sheet stock. The ID needs to be roughly 50 mm, the OD about 60 mm
and thickness that of the stock. The only critical dimension is the OD,
which has to be a snug fit in the groove where it'll live.

The sheet stock is what I happen to have. Likely most people would start
with bar stock then turn, bore and part off.

It's been a couple decades since I last did this, and all I can remember was
that fixturing was a bit of a pain. I think I turned the OD first, with the
stock pinched between chuck jaw tips and tailstock, but I can't remember how
I held the resulting disk to bore the ID. It's way too soft to hold in a chuck.

Everything I can think of involves making at least one faceplace fixture and
probably two. Can anybody point me to simpler methods? I'm not looking to save
time so much as material; I'm retired, so time is cheap but it looks like any
reasonable teflon stock will cost at least $100. And, it's good mental exercise.

Thanks for reading,

bob prohaska

"bob prohaska" wrote in message news:ul7ets$382no$1@dont-email.me...

I'd like to machine a few (2 or 3) teflon gasket rings out of quarter
inch sheet stock. The ID needs to be roughly 50 mm, the OD about 60 mm
and thickness that of the stock. The only critical dimension is the OD,
which has to be a snug fit in the groove where it'll live.

The sheet stock is what I happen to have. Likely most people would start
with bar stock then turn, bore and part off.

It's been a couple decades since I last did this, and all I can remember was
that fixturing was a bit of a pain. I think I turned the OD first, with the
stock pinched between chuck jaw tips and tailstock, but I can't remember how
I held the resulting disk to bore the ID. It's way too soft to hold in a
chuck.

Everything I can think of involves making at least one faceplace fixture and
probably two. Can anybody point me to simpler methods? I'm not looking to
save
time so much as material; I'm retired, so time is cheap but it looks like
any
reasonable teflon stock will cost at least $100. And, it's good mental
exercise.

Thanks for reading,

bob prohaska
----------------------
Holtzapffel's lathe book suggests turning ivory rings on a custom wood plug
or cup chuck. He claimed it would hold size for one day, perhaps two unless
the weather changed.

The plug chuck could be a snug fitting shouldered stub with the work held on
by tubing pressed against it by the tailstock, avoiding expansion. If you
don't have suitable tubing or don't need to check the final fit repeatedly
it could be held by screws and washers.

The outside chuck he suggests is a cup slotted into fingers and closed with
a ring sliding on an external taper. A simpler version could be a shallow
locating recess surrounded by screws and washers that catch the edge of the
work.

Both ID and OD can be turned by screwing the blank to plywood on a
faceplate. Fender washers can be bent into low profile step clamps.
The lathe bit will cut its own clearance in the wood. This is simpler but
provides less radial support.

"bob prohaska" wrote in message news:ul7ets$382no$1@dont-email.me...
....
The sheet stock is what I happen to have. Likely most people would start
with bar stock then turn, bore and part off.
....
-------------------------

If the stock is valuable I rough cut the ring or bushing's ID with a hole
saw.

On 12/11/2023 10:54 AM, Jim Wilkins wrote:
> "bob prohaska"  wrote in message news:ul7ets$382no$1@dont-email.me...
>
> I'd like to machine a few (2 or 3) teflon gasket rings out of quarter
> inch sheet stock. The ID needs to be roughly 50 mm, the OD about 60 mm
> and thickness that of the stock. The only critical dimension is the OD,
> which has to be a snug fit in the groove where it'll live.
>
> The sheet stock is what I happen to have. Likely most people would start
> with bar stock then turn, bore and part off.
>
> It's been a couple decades since I last did this, and all I can remember
> was
> that fixturing was a bit of a pain. I think I turned the OD first, with the
> stock pinched between chuck jaw tips and tailstock, but I can't remember
> how
> I held the resulting disk to bore the ID. It's way too soft to hold in a
> chuck.
>
> Everything I can think of involves making at least one faceplace fixture
> and
> probably two. Can anybody point me to simpler methods? I'm not looking
> to save
> time so much as material; I'm retired, so time is cheap but it looks
> like any
> reasonable teflon stock will cost at least $100. And, it's good mental
> exercise.
>
> Thanks for reading,
>
> bob prohaska
> ----------------------
> Holtzapffel's lathe book suggests turning ivory rings on a custom wood
> plug or cup chuck. He claimed it would hold size for one day, perhaps
> two unless the weather changed.
>
> The plug chuck could be a snug fitting shouldered stub with the work
> held on by tubing pressed against it by the tailstock, avoiding
> expansion. If you don't have suitable tubing or don't need to check the
> final fit repeatedly it could be held by screws and washers.
>
> The outside chuck he suggests is a cup slotted into fingers and closed
> with a ring sliding on an external taper. A simpler version could be a
> shallow locating recess surrounded by screws and washers that catch the
> edge of the work.
>
> Both ID and OD can be turned by screwing the blank to plywood on a
> faceplate. Fender washers can be bent into low profile step clamps.
> The lathe bit will cut its own clearance in the wood. This is simpler
> but provides less radial support.
>

If the only critical dimension is the OD, I suggest punch a hole in it,
rough cut it round by any means, and then bolt it to the end of a
mandrel with a support washer/cap on the outside. Turn to size. Glues
won't stick to any significant degree, but they may mechanically hold it
just enough to help you take light passes while holding it lightly with
your cap. PTFE will distort if you reef down on the bolt.
--
Bob La Londe
CNC Molds N Stuff

--
This email has been checked for viruses by AVG antivirus software.
www.avg.com

"Bob La Londe" wrote in message news:ul7j1p$38jot$1@dont-email.me...

If the only critical dimension is the OD, I suggest punch a hole in it,
rough cut it round by any means, and then bolt it to the end of a
mandrel with a support washer/cap on the outside. Turn to size. Glues
won't stick to any significant degree, but they may mechanically hold it
just enough to help you take light passes while holding it lightly with
your cap. PTFE will distort if you reef down on the bolt.
Bob La Londe

--------------------------------

A 2" pipe nipple faced square might serve for the mandrel. While the OD is
larger than 60mm the threaded end is slightly smaller.

On Mon, 11 Dec 2023 16:55:24 -0000 (UTC)
bob prohaska <bp@www.zefox.net> wrote:

>I'd like to machine a few (2 or 3) teflon gasket rings out of quarter
>inch sheet stock. The ID needs to be roughly 50 mm, the OD about 60 mm
>and thickness that of the stock. The only critical dimension is the OD,
>which has to be a snug fit in the groove where it'll live.
<snip>

You can buy "gasket cutters" that can work on PTFE up to 1/4 inch. See
for an assortment:

https://www.mcmaster.com/products/gasket-cutters/

This one isn't priced too bad and might do the job🤷

https://www.mcmaster.com/36795A11

--
Leon Fisk
Grand Rapids MI

"Leon Fisk" wrote in message news:ul7nf1$38ra1$1@dont-email.me...

You can buy "gasket cutters" that can work on PTFE up to 1/4 inch. See
for an assortment:

https://www.mcmaster.com/products/gasket-cutters/

This one isn't priced too bad and might do the job🤷

https://www.mcmaster.com/36795A11
Leon Fisk

----------------------------

If you've used one, how easy was it?

On Mon, 11 Dec 2023 14:36:12 -0500
"Jim Wilkins" <muratlanne@gmail.com> wrote:

>"Leon Fisk" wrote in message news:ul7nf1$38ra1$1@dont-email.me...
>
>You can buy "gasket cutters" that can work on PTFE up to 1/4 inch. See
>for an assortment:
>
>https://www.mcmaster.com/products/gasket-cutters/
>
>This one isn't priced too bad and might do the job🤷
>
>https://www.mcmaster.com/36795A11
>Leon Fisk
>
>----------------------------
>
>If you've used one, how easy was it?

I haven't used one. Just know they exist🤷

I have used the "Hole Saw" which is built in a similar style:

https://www.mcmaster.com/products/hole-cutters/adjustable-diameter-hole-saws-for-sheet-metal-10/

They work pretty well in a drill press. I've cut parts from 1/4 inch
steel using one. That's probably close to their limit. Using them in
a hand drill is highly dependent on the operators degree of finesse and
material being cut...

--
Leon Fisk
Grand Rapids MI

On 12/11/2023 10:55 AM, bob prohaska wrote:
> I'd like to machine a few (2 or 3) teflon gasket rings out of quarter
> inch sheet stock. The ID needs to be roughly 50 mm, the OD about 60 mm
> and thickness that of the stock. The only critical dimension is the OD,
> which has to be a snug fit in the groove where it'll live.
>
> The sheet stock is what I happen to have. Likely most people would start
> with bar stock then turn, bore and part off.
>
> It's been a couple decades since I last did this, and all I can remember was
> that fixturing was a bit of a pain. I think I turned the OD first, with the
> stock pinched between chuck jaw tips and tailstock, but I can't remember how
> I held the resulting disk to bore the ID. It's way too soft to hold in a chuck.
>
> Everything I can think of involves making at least one faceplace fixture and
> probably two. Can anybody point me to simpler methods? I'm not looking to save
> time so much as material; I'm retired, so time is cheap but it looks like any
> reasonable teflon stock will cost at least $100. And, it's good mental exercise.
>
> Thanks for reading,
>
> bob prohaska
>
>

I haven't seen anyone suggest this . If you can cut an accurate
center hole in the material (maybe screw a square piece to a wood block
held in your chuck) , machine a mandrel with a stub a half inch long
sized to fit that hole just snug and a cup that fits over the stub that
will clamp your gasket ring in place . Cut your center hole , clamp the
piece to the stub mandrel with the cup and tailstock ram , machine the OD .
--
Snag
Men don't protect women because they're weak .
We protect them because they're important .

"Snag" wrote in message news:ul8p8p$3hs8o$1@dont-email.me...

I haven't seen anyone suggest this . If you can cut an accurate
center hole in the material (maybe screw a square piece to a wood block
held in your chuck) , machine a mandrel with a stub a half inch long
sized to fit that hole just snug and a cup that fits over the stub that
will clamp your gasket ring in place . Cut your center hole , clamp the
piece to the stub mandrel with the cup and tailstock ram , machine the OD .
Snag

------------------------
Searching in the shed I found a 1-1/2" PVC pipe cap which has an ID of about
48mm and OD about 57mm.

On 12/11/2023 9:55 AM, bob prohaska wrote:
> I'd like to machine a few (2 or 3) teflon gasket rings out of quarter
> inch sheet stock. The ID needs to be roughly 50 mm, the OD about 60 mm
> and thickness that of the stock. The only critical dimension is the OD,
> which has to be a snug fit in the groove where it'll live.
>
> The sheet stock is what I happen to have. Likely most people would start
> with bar stock then turn, bore and part off.
>
> It's been a couple decades since I last did this, and all I can remember was
> that fixturing was a bit of a pain. I think I turned the OD first, with the
> stock pinched between chuck jaw tips and tailstock, but I can't remember how
> I held the resulting disk to bore the ID. It's way too soft to hold in a chuck.
>
> Everything I can think of involves making at least one faceplace fixture and
> probably two. Can anybody point me to simpler methods? I'm not looking to save
> time so much as material; I'm retired, so time is cheap but it looks like any
> reasonable teflon stock will cost at least $100. And, it's good mental exercise.
>
> Thanks for reading,
>
> bob prohaska
>
>

Wait. Are you the one that doesn't have machine tools like a mill or
lathe? Might be able to use a drill press, or even a hand held drill
motor, and bring it in a little at a time.

If this is the gasket for a compressor check valve, it might be that the
front and back faces are the sealing surfaces. I've used PTFE to make a
check valve gasket before, but it didn't last long for me. Maybe I did
a bad job, but the gasket wasn't the only thing flaky with it.

--
Bob La Londe
CNC Molds N Stuff

--
This email has been checked for viruses by AVG antivirus software.
www.avg.com

Bob La Londe <none@none.com99> wrote:
>
>
> Wait. Are you the one that doesn't have machine tools like a mill or
> lathe?

No mill or drill press. I do have a lathe, old South Bend 10k and
some limited tooling (3&4 jaw chucks, drill chuck for tailstock,
faceplates, boring tools, bits and random small extras like a steadyrest.
Oh, and a pedestal grinder the shaping bits.

> Might be able to use a drill press, or even a hand held drill
> motor, and bring it in a little at a time.
>

My problem (at least the one I recognize) is holding the workpiece
while finishing the ID. No problem making it spin 8-)

> If this is the gasket for a compressor check valve, it might be that the
> front and back faces are the sealing surfaces. I've used PTFE to make a
> check valve gasket before, but it didn't last long for me. Maybe I did
> a bad job, but the gasket wasn't the only thing flaky with it.
>

This is a group gasket for an old espresso machine, an Olympia Maximatic.
It seals on the faces, or one face and the OD depending on how tight it
fits in the groove. The face that seals against the basket needs to be flat.
For that reason a molded o-ring isn't satisfactory (I tried it).

The dimensions are rather odd. The groove ID is very close to 1.875", but
the OD is 2.293", which isn't anything I recognize as a common size.
The depth is about 5 mm, but the gasket normally sticks out another two
or 3 mm, there's quite a bit of freedom. I've been using a thin o-ring
to shim the gasket thickness, and that's worked surprisingly well. The
first gasket of this type that I made lasted close to twenty years, thus
my lack of recall in how I made it.

Thanks for reading and replying!

bob prohaska

On 12/12/2023 7:38 AM, Jim Wilkins wrote:
> "Snag"  wrote in message news:ul8p8p$3hs8o$1@dont-email.me...
>
>   I haven't seen anyone suggest this . If you can cut an accurate
> center  hole in the material (maybe screw a square piece to a wood block
> held in your chuck) , machine a mandrel with a stub a half inch long
> sized to fit that hole just snug and a cup that fits over the stub that
> will clamp your gasket ring in place . Cut your center hole , clamp the
> piece to the stub mandrel with the cup and tailstock ram , machine the OD .
> Snag
>
> ------------------------
> Searching in the shed I found a 1-1/2" PVC pipe cap which has an ID of
> about 48mm and OD about 57mm.
>

Robert's your mother's brother ... so all he has to do is machine the
stub arbor .
--
Snag
Men don't protect women because they're weak .
We protect them because they're important .

On Tue, 12 Dec 2023 19:54:22 -0000 (UTC), bob prohaska
<bp@www.zefox.net> wrote:

>Bob La Londe <none@none.com99> wrote:
>>
>>
>> Wait. Are you the one that doesn't have machine tools like a mill or
>> lathe?
>
>No mill or drill press. I do have a lathe, old South Bend 10k and
>some limited tooling (3&4 jaw chucks, drill chuck for tailstock,
>faceplates, boring tools, bits and random small extras like a steadyrest.
>Oh, and a pedestal grinder the shaping bits.
>
>> Might be able to use a drill press, or even a hand held drill
>> motor, and bring it in a little at a time.
>>
>
>My problem (at least the one I recognize) is holding the workpiece
>while finishing the ID. No problem making it spin 8-)
>
>> If this is the gasket for a compressor check valve, it might be that the
>> front and back faces are the sealing surfaces. I've used PTFE to make a
>> check valve gasket before, but it didn't last long for me. Maybe I did
>> a bad job, but the gasket wasn't the only thing flaky with it.
>>
>
>This is a group gasket for an old espresso machine, an Olympia Maximatic.
>It seals on the faces, or one face and the OD depending on how tight it
>fits in the groove. The face that seals against the basket needs to be flat.
>For that reason a molded o-ring isn't satisfactory (I tried it).
>
>The dimensions are rather odd. The groove ID is very close to 1.875", but
>the OD is 2.293", which isn't anything I recognize as a common size.
>The depth is about 5 mm, but the gasket normally sticks out another two
>or 3 mm, there's quite a bit of freedom. I've been using a thin o-ring
>to shim the gasket thickness, and that's worked surprisingly well. The
>first gasket of this type that I made lasted close to twenty years, thus
>my lack of recall in how I made it.

I'd be tempted to make the arbor section that the O-ring ID rests on
slightly undersize and machine the O-ring OD to the claimed dimension,
using a very sharp HSS cutting bit. Finding the right angle may
require some experimentation.

Then, when the new O-ring is installed, the ID part will force the
ring to expand against the OD component, sealing it.

This may be helpful:

..<https://www.quandaplastic.com/brief-introduction-of-turning-processing-method-of-teflon-ptfe-film/#:~:text=The%20cutting%20edge%20should%20be,be%2020%20~30%C2%B0%20above.>

Joe Gwinn

On 12/12/2023 1:54 PM, bob prohaska wrote:

>
> My problem (at least the one I recognize) is holding the workpiece
> while finishing the ID. No problem making it spin 8-)

> bob prohaska
>
>

Mount a wood block in your 4 jaw chuck (and face it off) . Tack or
screw a square piece of your material to the wood block . Machine the ID
.. See my other posts in this thread to proceed from there .
--
Snag
Men don't protect women because they're weak .
We protect them because they're important .

On 12/12/2023 3:19 PM, Snag wrote:
> On 12/12/2023 1:54 PM, bob prohaska wrote:
>
>>
>> My problem (at least the one I recognize) is holding the workpiece
>> while finishing the ID. No problem making it spin 8-)
>
>> bob prohaska
>>
>>
>
>   Mount a wood block in your 4 jaw chuck (and face it off) . Tack or
> screw a square piece of your material to the wood block . Machine the ID
> . See my other posts in this thread to proceed from there .

Wood block with a fender washer or similar large cap would work for
turning the outside. Then a large ring on the outside with screws, and
trepan and/or bore the ID.

--
Bob La Londe
CNC Molds N Stuff

--
This email has been checked for viruses by AVG antivirus software.
www.avg.com

"Snag" wrote in message news:ulam8u$3qv3u$1@dont-email.me...

Mount a wood block in your 4 jaw chuck (and face it off) . Tack or
screw a square piece of your material to the wood block . Machine the ID
.. See my other posts in this thread to proceed from there .
Snag

------------------------

Parting parallel to the spindle is called "trepanning". The tool is like a
1-tooth hole saw, or a parting tool with circular side relief, or enough
angular relief on the OD side to not drag.

I would have the ID-bored square clamped onto the centering stub as well as
screwed in the corners so it doesn't jump and tear when the OD cutter breaks
through and frees it.

"bob prohaska" wrote in message news:uladpe$3pjus$1@dont-email.me...

My problem (at least the one I recognize) is holding the workpiece
while finishing the ID. No problem making it spin 8-)

-------------------------

The proper chuck is a "pot collet" bored slightly larger than the work OD
with pins or shims in the slots to hold it open. When tightened the collet
clamps the work in place with full support all around.

This shows one with the chucked work being indicated, and empty, and also
compares and gives advantages of 5C vs ER such as square and hex collets,
which I have and use.
https://thecogwheel.net/2018/04/16/5c-collet-chuck/

This is the new URL for Metal Lathe Accessories, the collet chuck is MLA-21.
https://www.metallatheaccessories.com/

The quick and dirty substitute is the wooden cup chuck I mentioned. If you
need to turn only the ID and not the face of the ring it can be clamped with
screws and washers.

On 12/12/2023 23:48, Jim Wilkins wrote:
> "bob prohaska"  wrote in message news:uladpe$3pjus$1@dont-email.me...
>
> My problem (at least the one I recognize) is holding the workpiece
> while finishing the ID. No problem making it spin 8-)
>
> -------------------------
>
> The proper chuck is a "pot collet" bored slightly larger than the work
> OD with pins or shims in the slots to hold it open. When tightened the
> collet clamps the work in place with full support all around.
>
> This shows one with the chucked work being indicated, and empty, and
> also compares and gives advantages of 5C vs ER such as square and hex
> collets, which I have and use.
> https://thecogwheel.net/2018/04/16/5c-collet-chuck/
I totally agree with the comments there regarding pros and cons of 5C
and ER collets as I have both and have encountered some of those
limitations. For short items I have some 5C emergency collets machined
to suit and they work great except the Chinese makers substituted the
wrong sized pins, like 3.5mm instead of 1/8" but drilled the holes to
1/8" near enough. For the collet chuck I had considered buying a Bison
of that style which in my experience would have been top notch kit but
went for the Kalamazoo. I watched this video the other day about such 5C
closers https://www.youtube.com/watch?v=jQ3JutSejU4 and very little
runout but not built to last, but in the comments indications that other
similar 5C closers are better made at not that much extra price,
research required.
>
> This is the new URL for Metal Lathe Accessories, the collet chuck is
> MLA-21.
> https://www.metallatheaccessories.com/
Interesting to look at the accessories, one of my favourite  mods to my
lathe in recent years was to acquire a 2nd tailstock and modify it for
lever operation which I find I prefer for what I do over the standard
screw feed tailstock.
>
> The quick and dirty substitute is the wooden cup chuck I mentioned. If
> you need to turn only the ID and not the face of the ring it can be
> clamped with screws and washers.
>

"David Billington" wrote in message news:ulb6kd$rmg$1@dont-email.me...

On 12/12/2023 23:48, Jim Wilkins wrote:
> https://thecogwheel.net/2018/04/16/5c-collet-chuck/
I totally agree with the comments there regarding pros and cons of 5C
and ER collets as I have both and have encountered some of those
limitations.
---------------------
My lathe has the spindle adapter sleeve for 5C. Other than gripping range
what have you found for advantages of ER collets?

I use 6-jaw chucks for odd sizes, with the disadvantages of not being
precisely centered and the danger of the spinning jaws. Advantages over
collets are the jaw grooves that hold washers and thin rings and being able
to clamp an ID without using up part of an expanding arbor. A 3-jaw would
grab the washers too, one of the 6-jaws is usually on the lathe from the
last task. I haven't needed to thread thin tubing but if I did it could be
done concentrically at the right end, supported by a pipe center.

The gas filler hose on my 91 Ranger has a steel insert sleeve at the tank
with one end rolled outward into a press fit in the rubber tube. The edge
contacting the rubber was uneven and excessively large, and the rubber
eventually split there and leaked during filling. To fix it I turned the
rolled end smooth and a little smaller to fit the new hose more easily. This
was a good use for the 6-jaw and a contribution to paying back its cost.

Jim Wilkins <muratlanne@gmail.com> wrote:
> "bob prohaska" wrote in message news:uladpe$3pjus$1@dont-email.me...
>
> My problem (at least the one I recognize) is holding the workpiece
> while finishing the ID. No problem making it spin 8-)
>
> -------------------------
>
> The proper chuck is a "pot collet" bored slightly larger than the work OD
> with pins or shims in the slots to hold it open. When tightened the collet
> clamps the work in place with full support all around.
>

After some rumination, I think the original sequence of operations was
1. Hold the work blank by the outside scrap, finish the ID
2. Center the work by the ID, hold it by the face and finish the OD.

Initially I didn't like that sequence, because it required two accurate
operations of which only the second mattered, doubling the risk of error.

Looking at the tooling required for my preferred sequence, the original
method looks a bit simpler for only three parts. The idea of using pipe
caps for mandrels never crossed my mind and seems a good idea. They
can be run between centers, making them reproducible.

> This shows one with the chucked work being indicated, and empty, and also
> compares and gives advantages of 5C vs ER such as square and hex collets,
> which I have and use.
> https://thecogwheel.net/2018/04/16/5c-collet-chuck/
>
> This is the new URL for Metal Lathe Accessories, the collet chuck is MLA-21.
> https://www.metallatheaccessories.com/

Alas, my lathe uses 6k collets 8-(

Those are interesting links, thanks for posting!

Thanks to everyone!

bob prohaska

"bob prohaska" wrote in message news:ulcl6q$tph8$1@dont-email.me...

After some rumination, I think the original sequence of operations was
1. Hold the work blank by the outside scrap, finish the ID
2. Center the work by the ID, hold it by the face and finish the OD.

Initially I didn't like that sequence, because it required two accurate
operations of which only the second mattered, doubling the risk of error.

Looking at the tooling required for my preferred sequence, the original
method looks a bit simpler for only three parts. The idea of using pipe
caps for mandrels never crossed my mind and seems a good idea. They
can be run between centers, making them reproducible.
----------------------------

The wooden stub mandrel automatically solves the centering problem as long
as it's a close fit in all the rings, which you can ensure by boring the
ring blanks as a stack. My preference is oak, such as firewood, with the
grain along the lathe spindle axis which lets the lathe bit cut uniformly
all around; the grind for metal isn't ideal for wood. Alternately you could
screw two blocks of pine 2x4 together and chuck it in the 4-jaw.

"David Billington" wrote in message news:ulb6kd$rmg$1@dont-email.me...

I totally agree with the comments there regarding pros and cons of 5C
and ER collets as I have both and have encountered some of those
limitations.

----------------------

What do you think of this, which puts ER collets on a 5C indexer?
https://www.amazon.com/Accusize-Tools-Shank-Collet-0223-0302/dp/B07CT53WMC

On 14/12/2023 14:21, Jim Wilkins wrote:
>
>
> "David Billington"  wrote in message news:ulb6kd$rmg$1@dont-email.me...
> I totally agree with the comments there regarding pros and cons of 5C
> and ER collets as I have both and have encountered some of those
> limitations.
> ----------------------
>
> What do you think of this, which puts ER collets on a 5C indexer?
> https://www.amazon.com/Accusize-Tools-Shank-Collet-0223-0302/dp/B07CT53WMC
>

That looks like it might come in handy as I have a 5C indexer and a full
set of ER40 metric collets, my 5C collet set only contains some common
metric and inch round sizes acquired as needed or some common sizes to
have on hand just in case. I have a 5C 3 jaw self centring chuck for
dealing with hex stock. The ER40 full set was bought later and now sees
more use than the 5C and I have an ER40 square and hex block for 3,4,
and 6 but I can see the temptation to treat myself to one of those in
time for Christmas. Thanks for the heads up.

Here's a YouTube video of an alternative holding scheme for thin rings:

https://www.youtube.com/watch?v=7g_GtSpo5-A

It relies on a three jaw chuck for clamping a simple right
circular cylinder collet with a single split. Wish I'd seen
it sooner.

It's not clear I could have used it, as my three jaw chuck
didn't come with reversible jaws, but I'm still slightly
embarrassed that nothing like it ever crossed my mind.

Thanks for reading,

bob prohaska