I'm making an obsolete cartridge (351 Winchester) from brass that's currently obtainable (357 Max) which involves turning the 357 Max brass to take some diameter off the rim and also cut an extractor groove.  This was the bit that had me stumped - going to do the same on a much smaller scale, don't see why it wouldn't work!

Thanks!

Thank you

really well thought out solutions.  thanks for sharing...

thanks for showing this newbie.  well explained. i had to buy a 4" expanding collet.  problem is the 'part to be held' is about 4.1" ID.  im hoping i can buy a thin 4" ID stainless steel tubing, cut it to fit over the 4" expanding collet, cut a slit in the side. and my HOPE is this will then act as a solid enough shim to allow my piece to be held snugly.

Hey Joe,  Iv'e watched a lot of your videos.   I made a brief video in which you helped me make my part.... Thanks... Bob
https://youtube.com/shorts/nT3ZvtSP44I

Tou are a great Machinist
I really love these expansion arbors

它可以用于RFS下的圆孔基准定位。

Glad I found this older video. I need to clean up some O-ring grooves and OD's on some 90 deg hose nipple parts I had 3d printed in aluminum. I specified a small overage knowing I'd likely have to do this. Casting would have been the way but my volumes are low at the moment and it was cheaper to DLMS them in Chyna. The thread cap version with the screw accessible through the chuck side is exactly what I need!

Just used this on the wheelhead collar casting video (with full credit to you of course).  Another very useful technique.  Thanks Joe.

Do you make them to sell?.. I can find them and don't have the ability to make my own

I've seen many of your videos from the last 4 years and have learned so much. A web search brought me to this older one and it actually applies to my current project. I need to turn down an oilite bushing that is .625" ID, .875" OD and 2" in length. Final OD needs to be .718" the entire length. Using the O-ring method above, I'm finding the bushing is getting tapered by .003" (fatter at the tailstock). I suspect this is due to the deflection of the arbor at the tailstock end since the part is supported only at the headstock end. I think I'm asking too much of a .625" arbor with 2" of stick out. You might not have seen that while cutting acrylic. I think I will try to lathe file the fat end to the proper size, or, turn the bushing around to dial in the last few thousands (at the risk of losing concentricity).  Something for folks to be aware of. But thanks for posting, great ideas!

I have made several expansion arbors using pipe plugs.

subscribe, thank you.

Great idea Joe!  Thanks for the education.

Personally i wouldn't thread the slotted section

Thanks Joe. I remember watching this and then trying to find it (unsuccessfully) when I needed to make an expansion arbor and ended up making a pin chuck. Now I've found it again I will add the o ring arbor to my toolbox.

Great idea! I'm curious about the level of concentricity achieved when the part is internally clamped. Is it better achieved with the use of seals or without?

Thank you SO much for sharing your expertise, that's so humble of you. Like and subbed on the spot!!

Top, very useful

Has the Smithsonian made a formal request for you to allow them to preserve your brain for posterity? Genius!