Creative workholding

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mars-red
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Creative workholding

Post by mars-red » Fri Jun 28, 2013 11:52 am

I'm sure we all have to meet challenging work holding demands from time to time, and I'm curious to see some of the work holding challenges others have faced, and how they were addressed.

Not too long ago I had to make a couple of very small round nuts with tapered OD... really impossible to hold in a collet or most chucks. If I had a bezel chuck, that would have worked very well... but I don't. It wasn't much of a challenge, as they were threaded, I obviously needed a little threaded arbor to hold them in place. Specifically, I needed to reverse them after parting to clean up and polish the parted side (if I was better at parting off, it probably wouldn't have been necessary at all).

These were the parted off tapered nuts:
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And the bespoke threaded arbor (M1.4 threads):
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And the threaded arbor in use, turning down the parted side of one of the tapered nuts (I made a little plastic washer to take up space and protect the polished surface of the nut, and as you can see it was some type of plastic that didn't machine very well at all):
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I later had a similar situation, with a couple of parts that had through holes and steep tapers on the OD, and I experimented with a little expanding arbor, with the idea I could make different split collars to accommodate a small range of sizes as needed:
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That one worked fine but was really fiddly to set up due to the collar being slit on just one side. Next time I'll try making a few slits from each side of the collar, sort of like an ER collet, so that it can expand evenly.

And then there was my makeshift faceplate... this was less creative and more just being lazy/impatient. I had started making a combination tailstock drilling table and turning faceplate, but haven't finished it yet. When I hit the need to mount some flat work in a faceplate, I drilled and tapped a couple of holes where I was planning on milling slots anyway, so that I could use a couple of bolts to secure the work:
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tornitore45
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Re: Creative workholding

Post by tornitore45 » Fri Jun 28, 2013 1:06 pm

Good work!

What is a bezel chuck?
Mauro Gaetano
in Austin TX

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mars-red
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Re: Creative workholding

Post by mars-red » Fri Jun 28, 2013 1:22 pm

tornitore45 wrote:Good work!

What is a bezel chuck?
Thanks Mauro! A bezel chuck is a special type of scroll chuck with stepped jaws (they seem to typically have 6 jaws), I think the name comes from their use to hold instrument bezels in place... but they seem useful for a lot of other things too. Here is a pic of a particularly nice one, on a little Cowells lathe:
Image

Hopefully others here will chime in with how they addressed some of their own work holding challenges. :)

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tornitore45
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Re: Creative workholding

Post by tornitore45 » Fri Jun 28, 2013 2:29 pm

Thanks.
I am now aware of yet one more nifty tool I do NOT have. Rats.
Mauro Gaetano
in Austin TX

whateg0
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Re: Creative workholding

Post by whateg0 » Sat Jun 29, 2013 3:51 am

My faceplate that I am in the process of finishing up is just going to have tapped holes. I plan on putting a pattern of 1/4"-20 holes on it and will just either clamp using these, or drill holes in workpieces to be attached. I hate trying to deal with t-nuts on most anything but the mill table. I'll post a picture of it when it's done.

I wish I had a pic of it, but I can't find one. A buddy of mine had an oddly shaped part to machine on the mill. No real way to clamp it, so he ended up dropping it in some plaster and letting it set. He used light cuts, but it held up really well. Easy to take out afterward, just needing some light cleanup. Obviously wouldn't work in all situations, but one makes do.

Dave

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tornitore45
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Re: Creative workholding

Post by tornitore45 » Sat Jun 29, 2013 7:19 am

Plaster potting = another technique to store away until needed, someday.
Mauro Gaetano
in Austin TX

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jim314159
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Re: Creative workholding

Post by jim314159 » Sun Jun 30, 2013 12:53 pm

I love the approach of using the bolt heads to clamp down that small square part for boring. Reminds me of the old axiom, "if it's stupid and it works, it's not stupid!"

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mars-red
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Re: Creative workholding

Post by mars-red » Mon Jul 01, 2013 10:48 am

jim314159 wrote:I love the approach of using the bolt heads to clamp down that small square part for boring. Reminds me of the old axiom, "if it's stupid and it works, it's not stupid!"
LOL I had never heard that saying before, I like it. :)
whateg0 wrote:My faceplate that I am in the process of finishing up is just going to have tapped holes. I plan on putting a pattern of 1/4"-20 holes on it and will just either clamp using these, or drill holes in workpieces to be attached. I hate trying to deal with t-nuts on most anything but the mill table. I'll post a picture of it when it's done.

I wish I had a pic of it, but I can't find one. A buddy of mine had an oddly shaped part to machine on the mill. No real way to clamp it, so he ended up dropping it in some plaster and letting it set. He used light cuts, but it held up really well. Easy to take out afterward, just needing some light cleanup. Obviously wouldn't work in all situations, but one makes do.
Dave
That's a neat idea about the plaster bed... a lot of the stuff I do involves taking really light cuts so that may come in useful for me someday! I'll keep my eyes peeled for a pic of your faceplate, I really enjoy seeing stuff other people have made.

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Re: Creative workholding

Post by Harold_V » Mon Jul 01, 2013 3:21 pm

jim314159 wrote:I love the approach of using the bolt heads to clamp down that small square part for boring.
Not all that uncommon when doing small work. An added benefit is the use of a washer under the screw/bolt head, to limit the ability of the fastener to move the part when it's tightened.

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.

eightball
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Re: Creative workholding

Post by eightball » Thu Jul 25, 2013 9:25 am

I am assuming you are the same mars from the home shop machinist site. I recognize the penny lol. I recently joined that site also and was really amazed at some of your homemade tools. This thread is appx 200 pages and well worth the read. Great work

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mars-red
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Re: Creative workholding

Post by mars-red » Fri Jul 26, 2013 10:37 am

eightball wrote:I am assuming you are the same mars from the home shop machinist site. I recognize the penny lol. I recently joined that site also and was really amazed at some of your homemade tools. This thread is appx 200 pages and well worth the read. Great work
Yes I'm afraid that's me - guilty as charged. :) Thanks for the compliment!

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