# Failed Shim Punch Project



## YYCHM (Nov 13, 2018)

Image 1 - I attempted to clone a shim punch for punching shims from 8 thou steel shim stock.

Image 2 - A punch set I borrowed to clone.  It works quite well.

Image 3 - My first attempt.  It produced one useable shim and the proceeded to mangle every one there after.
                 The ID punch works fine.  The OD punch not so much.

Image 4 - I attempted to re-do the OD punch two more times, including lapping the punch to the die using valve grinding compound. No luck.

Soooo, I'm at a loss now as to what to try next.  Wrong materials perhaps?  I used steel plate and round bar scrounged from the MSM per pound scrap bins.  Tolerances not close enough?  The die was drilled on my crappy table top drill press, the punches were turned on my 7X12.  I milled the die plates with a step rather than using washers to separate the two plates after I got my mill.  That didn't help.

Thoughts?

YYCHM


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## DPittman (Nov 13, 2018)

I'm going to guess it has to do do with your drill press.  If I understand your project correctly, the hole made with the drill press is the one forming the OD of the shim....drill presses do not make very nice round holes and cheap drill presses are even worse.


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## PeterT (Nov 13, 2018)

I'm impressed you got that far, they look very delicate & fiddly to get knocked out & maintain dimensions without distorting. I've never made them myself but have seen some similar application punch & dies. On those the surfaces look pretty shiny & close tolerances & same for the ram. Wouldn't surprise me if they were hardened & ground but maybe unnecessary for your purpose unless you are contemplating production. Seems to me the punch ID had a coved edge looking from the side & that cutting cylinder somehow stayed inside the donut to stabilize when the OD cut came down. But cant recall where I saw this. Maybe How Its Made show or similar & maybe washers so maybe N/A to your application.

I've seen some model engine guys make head shims as thin as 0.001" using something similar to Joe Pie method below, but they were brass. Another option depending on your  pocketbook is laser cutting. I've heard that thin metals can give them grief though because they need to sit flat. You can laminate them to something sacrificial but lasers don't like that sandwich layup because it diffuses the beam on the crack & affects surface finish? You'd have to check but that was my understanding.


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## YYCHM (Nov 13, 2018)

"I'm going to guess it has to do do with your drill press.  If I understand your project correctly, the hole made with the drill press is the one forming the OD of the shim....drill presses do not make very nice round holes and cheap drill presses are even worse."

Would my mill do a better job of cutting the ID/OD die holes?

The shim ID is 11/16 and the OD is 7/8.  The punch set I cloned was crafted by a  tool and die maker and show it.


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## kevin.decelles (Nov 13, 2018)

I splurged some time back and went with the Precision true-punch set like this one from KBC tools Precision tru-punch.  I can't recall paying over 300 for it though.

I use it mainly to cut shims for old machinery.  Very slick.  The interesting part is that the punch itself is made of tool steel, but the top of the guide block is some form of plastic/acrylic on a metal base.  Extremely tight tolerances on everything.

I bought it after years of butchering shim stock with everything from scissors to snips to utility knife etc.  Next I started ordering pre-cut shims from Fastenal, and after a couple of orders, just bought the machine and buy my shim stock in rolls/flat sheets.

Still cheaper than the machinist hammer I made at SAIT though.


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## YYCHM (Nov 13, 2018)

The shim ID needs to be 11/16 and the OD 7/8 or there abouts.   I don't think a universal shim punch will cut that, also, not prepared to spend more than $100 on this project.  A tool and die maker already quoted me $300+ to build one.

So, can I make this work or not?  I'm already into it for $50 worth of materials but willing to give it another go if it's feasable.


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## Dabbler (Nov 13, 2018)

So here is how I'd make them on my lathe.  I'd superglue the shim stock to the end of aluminum bar stock.  turn the OD.  then with a sharp HSS tool trepan the ID.  torch, and the shim is free.  Reface the end of the bar stock.  repeat.


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## YYCHM (Nov 14, 2018)

Dabbler said:


> So here is how I'd make them on my lathe.  I'd superglue the shim stock to the end of aluminum bar stock.  turn the OD.  then with a sharp HSS tool trepan the ID.  torch, and the shim is free.  Reface the end of the bar stock.  repeat.



The point of using the punch set is to repeatedly bang out a 1/2 dozen or so shims on short notice.  What you're suggesting is way too time consuming.


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## John Conroy (Nov 14, 2018)

I think the holes in the plate need to be bored using a boring head on your mill. They need be as close to zero clearance with the male punch as possible or the thin shim stock will just fold instead to shearing.


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## YYCHM (Nov 14, 2018)

John Conroy said:


> I think the holes in the plate need to be bored using a boring head on your mill. They need be as close to zero clearance with the male punch as possible or the thin shim stock will just fold instead to shearing.



Zero tolerance was what I tried to accomplish by lapping the punch to the die.  Perhaps the lapping just exasperated an out of round problem?  Is tool steel required for this application?  Note the guide pins on the punch set I attempted to clone.  Would that be a key element in this puzzle?


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## John Conroy (Nov 16, 2018)

I think you're right. Lapping can only make a hole larger so that's not the answer. If you're going to use it a lot then mild steel is not the material to use. The alignment pins would make for consistant function of the tool I  think. How big are the plates? I have a round log of 4340 tool steel 6.75 inches in diameter. If you want a couple of slices from it let me know.


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## Dabbler (Nov 16, 2018)

YYCHobbymachinist, I went back to see how many you were going to do, and didn't find a quantity....

  There's a technique used in commercial punch and die sets, where the punch has both diameters built right in, where you take materrial, punch the inside hole and it says on the punch and the second shoulder is for the outer cut.  the die is aligned in the second case by boring a clearance cavity and leaving an alignment hole at the bottom of the hole.

If you are remaking your punch set, this might help.


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## YYCHM (Nov 17, 2018)

John Conroy said:


> I think you're right. Lapping can only make a hole larger so that's not the answer. If you're going to use it a lot then mild steel is not the material to use. The alignment pins would make for consistant function of the tool I  think. How big are the plates? I have a round log of 4340 tool steel 6.75 inches in diameter. If you want a couple of slices from it let me know.



Two 1/2" slices would suffice for making the die plates thanks.  I'll PM you.

Any idea where I can source 1" round stock tool steel.  Need two pieces 4" long.  MSM only lists drill rod when you attempt to quote on-line.


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## YYCHM (Nov 17, 2018)

Dabbler said:


> YYCHobbymachinist, I went back to see how many you were going to do, and didn't find a quantity....
> 
> There's a technique used in commercial punch and die sets, where the punch has both diameters built right in, where you take materrial, punch the inside hole and it says on the punch and the second shoulder is for the outer cut.  the die is aligned in the second case by boring a clearance cavity and leaving an alignment hole at the bottom of the hole.
> 
> If you are remaking your punch set, this might help.



Sorry, me bad, should have mentioned quantity in my OP.

As for this other technique, do you have an image or a link to such an arrangement.  I'm having a hard time getting my head around how that would work.


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## YYCHM (Nov 17, 2018)

John Conroy said:


> I think the holes in the plate need to be bored using a boring head on your mill. They need be as close to zero clearance with the male punch as possible or the thin shim stock will just fold instead to shearing.



Would the holes need to be bored or would plunging the appropriately sized end mills into the die plates suffice?


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## Dabbler (Nov 17, 2018)

I'll do up a drawing later today.  the hole has to be bored, not milled for accuracy and concentricity.  Neither is likely when just plunging with an end mill - sure you can hole to a thou or 2 on an accurate bore by plunging, but that is unlikely to be good enough is the shim stock is very thin.


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## PeterT (Nov 17, 2018)

Drill rod is dimensionally pretty decent tolerance & finish. It can be machined in its stock (annealed) condition as it arrives & then hardened & quenched, which is exactly what its intended for. I suppose you could locally heat the end only, quench & temper, depending on your resources. I have done smaller stuff with torch & oven to temper. It typically comes in 36" lengths in rounds. Here are some prices from KBC. A=Air W=water O=oil. Unfortunately, not exactly cheap in that larger diameter.


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## Dabbler (Nov 18, 2018)

Sorry my CAD program is buggered... I'll have to draw it by hand and send it to you.  Too busy right now, but soon.


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## YYCHM (Nov 18, 2018)

Dabbler said:


> The hole has to be bored, not milled for accuracy and concentricity.  Neither is likely when just plunging with an end mill - sure you can hole to a thou or 2 on an accurate bore by plunging, but that is unlikely to be good enough is the shim stock is very thin.



Would a reamer do the job?

Where does one find a mill boring tool for something 11/16 to 14/16?


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## Dabbler (Nov 18, 2018)

OK got it running again - gotta love Windows 10!






Any boring head that will fit your mill will do.


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## YYCHM (Nov 18, 2018)

Dabbler said:


> OK got it running again - gotta love Windows 10!
> 
> View attachment 3730
> 
> Any boring head that will fit your mill will do.




You have lost me.... How does this thing work?

Not seeing any mill boring tools for 7/8" or there abouts etc????


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## YYCHM (Nov 18, 2018)

Dabbler said:


> OK got it running again - gotta love Windows 10!
> 
> View attachment 3730
> 
> Any boring head that will fit your mill will do.




Explain this punch please.  I don't understand how it works.


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## PeterT (Nov 18, 2018)

This is a an adjustable boring head used in a mill.


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## YYCHM (Nov 18, 2018)

PeterT said:


> This is a an adjustable boring head used in a mill.



OK.... down to 1/2".  Where?


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## PeterT (Nov 18, 2018)

I don't understand your question.


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## PeterT (Nov 18, 2018)

maybe this will help


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## Dabbler (Nov 19, 2018)

YYC  perhaps we need to have coffee one day, I just don't know what else to say.


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## YYCHM (Nov 19, 2018)

PeterT said:


> maybe this will help



That explained it.  I thought the tool was mounted on the side of the head, thus my confusions as to how one could stuff the head in such a small hole.

Thanks!!!


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## YYCHM (Nov 20, 2018)

I think what I'll do is pickup a boring head and try boring the OD hole on the die I have and turn a matching punch to see if that improves the situation.

When it comes to boring heads I see designations such as 2", 3" etc.  What does the 2", 3" represent?
When it comes to boring head tooling I see designations 3/8", 5/8" etc. What do these measurements represent?

Thanks,


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## PeterT (Nov 20, 2018)

2" & 3" is the nominal OD of the head itself
3/8" & 1/2" is the shank diameter of tools that insert into head via the holes you see. They are standardized, kind of similar to IMP end mill holders.

Larger heads have longer throws so extending the radius you can bore bigger holes. But they also are heavier & more expensive. BH sizing is more about the mill you have, the power, intended work & available headroom. Don't underestimate headroom on a smallish mill. By the time you insert a boring head, have a tool sticking out the bottom (even a stubby) vs the work piece + vise.. it can gobble up vertical height pretty quick. Get some measurements off the net & mock this up before you commit the $$.


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## YYCHM (Nov 21, 2018)

Boring the die hole ID to match the punch OD appears to have done the trick.

I picked up a 2" boring head and a set of 3/8" boring bars today.






After cleaning up the OD punch on my lathe,  I proceeded to bore the die OD hole to just fit the punch.
This worked way better than what I did before which to try to turn the punch to match the die.






The OD punch and die is now cutting the shim ODs nice and clean and round.  The ID punch and die now need the same treatment as they are tearing the shim ID more often than not.  Still better than what was occurring before.






Getting closer.  OD looks good, ID not so much.

Note that I also pinned the die plates in two places.


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## Bofobo (Nov 22, 2018)

Your punch should be shaped like this, i used/built a shop made, item specific pneumatic punch ( making shim reinforced rubber valves for a classified project) case hard is a good idea, and a guide block matched to the punch plate for the close tollerances required for repeatability.


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## kylemp (Nov 23, 2018)

I'm not sure that this has come up but you will need to grind the od of the punch tool with back relief and the face with a concave(I think I've got it right, center needs to be back from the rim) as well. Then you pretty much have to do the inverse to the plate that it mates with. The idea is that you get a shearing action at the faces but it doesn't have to fight to keep going, once you have the cut completed there needs to be a little room for the punch in the die. Look at rotary broaching for the general idea on relief on the punch tool. There's a lot of information on this subject out there. If I remember right stefan gotteswinter has done this exact thing and I'd doubt anyone on this forum has a better background and can explain or make this tool as well..


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## historicalarms (Nov 24, 2018)

Just an observation here after a re-look at the photo's with a suggestion . I noticed your hold-down bolts are all on one side...would this not pinch one side of your shim stock in your form and tilt the forming base off the shim stock on the other side of the hole causing a tear instead of a cut after the center I.D. is cut out. The shim stock can "pull" from between the holding plates  instead of cutting cleanly.  

    I would add a couple more locking bolts on the opposite side and give er a try.


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## YYCHM (Nov 24, 2018)

historicalarms said:


> Just an observation here after a re-look at the photo's with a suggestion . I noticed your hold-down bolts are all on one side...would this not pinch one side of your shim stock in your form and tilt the forming base off the shim stock on the other side of the hole causing a tear instead of a cut after the center I.D. is cut out. The shim stock can "pull" from between the holding plates  instead of cutting cleanly.
> 
> I would add a couple more locking bolts on the opposite side and give er a try.



The two die plates need enough separation to slide the shim stock between them by hand.  At first I caused the separation using washers between the plates but later milled a step into the top die plate to achieve the separation.

You slide the shim stock into the clearance slot between the die plates and punch the ID hole.  Then you slide the shim stock ID hole to the die plate OD hole, align the OD punch with the ID hole in the shim stock using the OD punch nose step and punch the shim.  Note the step (for better words) on the nose of the OD punch.  That is used to align the shim stock ID hole with the OD die plate hole.  Creating a cutting edge in that step was quite a challenge. I ended up using one of the small hand ground HSS tools you supplied with my lathe






Does that description make any sense at all???


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## historicalarms (Nov 25, 2018)

Yes it does, it works identically to the pop can gas check cutter I built a few years ago from Youtube plans only I didn't have to cut an inside dia first, I just made discs.  It had a sliding gap also and had the same problem you are having with ragged cut edges. I cut the alum. into strips and fed them into the die cutter one cut at a time.  You could cut the shim stock into strips in your case then a couple of bolts on the opposite side wouldn't interfere with your feeding the shim stock in.

    I think if I were building one I would forego the step between the two plates so they could be locked together. I would also put my cutter holes closer together, that way I could feed a strip in from one way and cut an inside dia. then an OD at the second hole all with one "pinch" then loosen the lock bolts and slide new shim material under the holes, lock down and cut in both holes. It will take a little longer in operation but I think the finished product will be better.


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## YYCHM (Nov 25, 2018)

historicalarms said:


> Yes it does, it works identically to the pop can gas check cutter I built a few years ago from Youtube plans only I didn't have to cut an inside dia first, I just made discs.  It had a sliding gap also and had the same problem you are having with ragged cut edges. I cut the alum. into strips and fed them into the die cutter one cut at a time.  You could cut the shim stock into strips in your case then a couple of bolts on the opposite side wouldn't interfere with your feeding the shim stock in.
> 
> I think if I were building one I would forego the step between the two plates so they could be locked together. I would also put my cutter holes closer together, that way I could feed a strip in from one way and cut an inside dia. then an OD at the second hole all with one "pinch" then loosen the lock bolts and slide new shim material under the holes, lock down and cut in both holes. It will take a little longer in operation but I think the finished product will be better.




I tried clamping the shim stock between the die plates, it didn't help matters.  I agree that supporting the shim gap on two sides would be a good idea though, especially, since I'm using mild steel for the die plates.


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## historicalarms (Nov 25, 2018)

The only shim stock I have ever used is in a hardened state, is there other "softer" stuff available . Cutting the 2 thou thick stuff I have would "roll" the sharp edge off mild steel in a very few cuts I think....I know you are searching for some hard plate and hope you find some.


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## YYCHM (Nov 25, 2018)

historicalarms said:


> The only shim stock I have ever used is in a hardened state, is there other "softer" stuff available . Cutting the 2 thou thick stuff I have would "roll" the sharp edge off mild steel in a very few cuts I think....I know you are searching for some hard plate and hope you find some.



It's pretty obvious that the material I'm using for the punches is way too soft.  Note the amount of distortion occurring at the hammer end.  The punches started out as PA cylinder pins.  Strange stuff.  Hard on the outside and gets progressively softer towards the middle.

At this point in time I'm in proof of concept mode.  This morning I turned a new ID punch and bored the ID die plate hole to match.  It would appear that I'm back to mangle mode again for some unknown reason.

If tapers are key here I sure didn't notice any on the commercial punch set I borrowed to clone.


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## kylemp (Nov 25, 2018)

YYCHobbyMachinist said:


> It's pretty obvious that the material I'm using for the punches is way too soft.  Note the amount of distortion occurring at the hammer end.  The punches started out as PA cylinder pins.  Strange stuff.  Hard on the outside and gets progressively softer towards the middle.
> 
> At this point in time I'm in proof of concept mode.  This morning I turned a new ID punch and bored the ID die plate hole to match.  It would appear that I'm back to mangle mode again for some unknown reason.
> 
> If tapers are key here I sure didn't notice any on the commercial punch set I borrowed to clone.


The taper needs to be there or you're going to continue to have some serious issues. Die work requires a high degree of precision. 
I still think for what you're doing a lathe like the video I posted above would be a better option unless you're making 1000 a day forever.
If you're intent on trying to do this as a punch die you're going to have to get into grinding probably or it might work for a little while and then stop working.


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## YYCHM (Nov 25, 2018)

kylemp said:


> If you're intent on trying to do this as a punch die you're going to have to get into grinding probably or it might work for a little while and then stop working.



I dare say you may have hit the nail on the head here.  A few successes has kept me poking at it.  I've gone full circle at least 5 times now.  She ain't gonna fly with the skill sets, material and equip I have.  I'll scrap the punch set idea and study the lathe solutions now.

Thanks


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## kylemp (Nov 25, 2018)

YYCHobbyMachinist said:


> I dare say you may have hit the nail on the head here.  A few successes has kept me poking at it.  I've gone full circle at least 5 times now.  She ain't gonna fly with the skill sets and equip I have.  I'll scrap the punch set idea and study the lathe solutions now.
> 
> Thanks


If you want to keep trying I think the other portion that you're likely missing is alignment on the punch. If you can find a way to steady the punch in relation to the die and lock them both down and ensure that it move perpendicular to the die you'll likely have better success. Reamers are your friend in this case, if you have a reamer or can cut a good fi ish accurate bore with your mill or lathe you may be able to weld up a fixture for an arbour press or something similar that would keep the punch constrained to move straight up and down in relation to the die and still have room to cut some relief in the punch and die. You might also get away with just cutting relief in the die.. But cutting a taper on a mill correctly isn't easy. At the very least - is your stock all ground? This isn't going to work with her tolled or probably even cold roll steel for the punch and die. If you want to learn more about it I'd suggest finding some information on ironworker dies probably.

Also check out


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## YYCHM (Nov 25, 2018)

"her tolled"?   Do you mean "hot rolled"?  

I've been using mild steel, nothing special, and couldn't tell you what it is actually.  The punches started from PA cylinder pins.  The die plates were scrap sourced from MSM.


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## PeterT (Nov 25, 2018)

The Stefan video is very informative. Notice a few key elements:
- brass shim stock washer material = relatively soft compared to mild steel & particularly anything approaching spring steel shim stock if that was ever the goal
- 0.2mm thick (= less that 0.008") so again easier to shear than maybe what you are trying?
- pins are HSS & dowel pin = very hard. I'd guess 62-65 Rockwell C. This ties in with what I was suggesting about heat treating is very likely a pre-requisite
- block was D2 tool steel. This is an air hardening tool steel, although I believe he said he did not harden. In its annealed state, still pretty tough stuff. He mentioned nice bore & relief (not taper) which I think has more to do with parts fall-through clearance.

Even with this relatively thin/weak/small material you could hear the 'thwunk' as the pin sheared through. It makes me cringe a bit seeing his mill spindle in this manner bearings wise, but anyway. So reflecting on your project, hopefully you can see the differences. More cutting area, stronger, thicker stock, softer shearing tools & a different recipe of clearances involved.


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## YYCHM (Nov 27, 2018)

After reviewing the lathe turning option(s), I have concluded that it demands too much sacrificial material.

Looks like this project has me beat.  I hate admitting defeat, but that's how it goes sometimes.


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## Dabbler (Nov 27, 2018)

YYC Janger already gave you a great solution to your feet issue.  Ask him to send you a photo of his vise knobs.  They are very impressive.


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## YYCHM (Nov 27, 2018)

Dabbler said:


> YYC Janger already gave you a great solution to your feet issue.  Ask him to send you a photo of his vise knobs.  They are very impressive.



Wrong thread?


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## Dabbler (Nov 27, 2018)

perhaps re-drilling/tapping can be accomplished...


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## YYCHM (Nov 27, 2018)

Dabbler said:


> YYC Janger already gave you a great solution to your feet issue.  Ask him to send you a photo of his vise knobs.  They are very impressive.



Wrong forum thread.  This thread has nothing to do with feet or vise knobs.  I assume your talking about the guy looking for custom brass speaker tower bases/feet.


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## Dabbler (Nov 27, 2018)

oops.  sorry. I was just reading the other thread and got cross wired.....  -- How worn out is that pulley?


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## DPittman (Jan 29, 2021)

So did you find a solution to your problem @YYCHobbyMachinist ?


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## YYCHM (Jan 29, 2021)

DPittman said:


> So did you find a solution to your problem @YYCHobbyMachinist ?



Nope.  Came to the conclusion it wasn't worth chasing any further.


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## Degen (Dec 25, 2021)

Sorry I wasn't on the site back then, the solution is drill (or punch) medallions of shim stock to ID, place a bunch on a mandrel clamp tight, throw on lathe turn OD.

Works with any material that can't be held but can be compressed without deformation.

I do this for plastic nylon washers for one of my products.


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## Janger (Dec 25, 2021)

Degen said:


> Sorry I wasn't on the site back then, the solution is drill (or punch) medallions of shim stock to ID, place a bunch on a mandrel clamp tight, throw on lathe turn OD.
> 
> Works with any material that can't be held but can be compressed without deformation.
> 
> I do this for plastic nylon washers for one of my products.


Products? You make products? Let’s hear about that!


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