Expanding Collet types

Gotcha! They looked suspiciously like napkin holder rings to me! :tranquility:
 
I have been using expanding collets for about 50 or more years. Hardinge makes them and another US company is Rovi in Ca. I have used all kinds of them. To use them put then in spindle until they are expanded about ten thousands then turn to bore size of part . Don’t turn them much under the bore size. I use them mostly with my lever collet closer. When running in production you can load and unload in seconds never needing to stop spindle. I have used then to hold parts up too 6 inches dia. Here is pic of a few Rovi brand collets I have in my shop. You can also expand them by using a draw bar made out of 1/2 inch all thread with a 1/4 drawbolt thru the spindle expanded with a nut and wrench.


https://photos.app.goo.gl/T3KLvsaq1h8LV2D43
 
Hi Jim,

Thanks for posting this. From the picture you posted

P1010864.JPG
It appears to me that the threaded end carries and pulls back the expanding bolt so the front Jaws, for want of a better word, expands as the collet is pulled in tight. The threaded section "floats" separate from the collet shank. Have I understood them correctly.?

If I have understood correctly that's what I'm looking for.
 
Boris Ludwig said:
Hi Jim,

Thanks for posting this. From the picture you posted

View attachment 258730
It appears to me that the threaded end carries and pulls back the expanding bolt so the front Jaws, for want of a better word, expands as the collet is pulled in tight. The threaded section "floats" separate from the collet shank. Have I understood them correctly.?

If I have understood correctly that's what I'm looking for.
Click to expand...
Boris Ludwig said:
Hi Jim,

Thanks for posting this. From the picture you posted

View attachment 258730
It appears to me that the threaded end carries and pulls back the expanding bolt so the front Jaws, for want of a better word, expands as the collet is pulled in tight. The threaded section "floats" separate from the collet shank. Have I understood them correctly.?

If I have understood correctly that's what I'm looking for.
Click to expand...
Boris Ludwig said:
I'm using 5C collets and I want to turn pressed nickel silver cups and rings for reel seats. here's an example.


View attachment 258107

So after the cups are drawn I can turn them to finish them off and part the ring from the cup etc.
My questions are expanding 5C collets readily available, if so, where?

Also to make rope knurling I assume I need a special tool. Are fine tools for these applications readily available?
Click to expand...
Boris Ludwig said:
Thanks to all for the tips photos and links.
Click to expand...


Here is a couple of other ways to use expanding collets. I way top left in pic is to make a tapered spindle adapter with a threaded Id that takes a home made expanding collet. Taper matches spindle taper. The adapter on the top right in pic
Screws onto the 2 1/4 8 thread of the lathe and has a Id thread on the end where you screw expanding collets into. When I did a lot of production work I made up bunches of the collets from bar stock. I would make up 20 or 30 collets at a time.
I had 4 automatic turrets with 5c spindles on them. I sawed the collet slots on my band saw. In the pic are some Rovi brand collets and some of the shop made ones I made. The collets can be returned to smaller size for other jobs.

https://photos.app.goo.gl/eJg5nx3dtT8pmTlI2
 
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