Making a Custom Collet to hold a chrome part on a lathe

[theeddies]

[Altair]

Thanks theeddies! We've added your Custom Collet to our Lathe Accessories category,
as well as to your builder page: theeddies's Homemade Tools. Your receipt:

Custom Collet by theeddies

tags: collet

[Toolmaker51]

Collets like these are a good solution for many instances. Fact that yours is blind [closed end] keeps the same ends 'tied' together. With a through collet, sometimes a maker will split both sides, without a distinguishing feature to reorient as intended, especially hand split.
Cut a tell-tale groove on one end, a larger chamfer, long as it is easily recognized.
I nearly always split both sides, so preference is a shoulder; easily identifies one end, and registers on the jaw face.

[theeddies]

Are you saying, split it kind of like an ER collet except without the taper? In other words an open tube split (in this case) three times from each end, alternating/offsetting the cuts so that it collapses more equally along its length. And then an interior shoulder on one side to orient and register the part?

[Toolmaker51]

Theoretically and some visualization.
1 cut [not split] pinches diameter in 3 places at the opening, two adjacent to the cut and one at opposite side. It will only hold concentric if they are same size. The pinch can introduce axial loss of concentricity.
Splitting collet makes contact along length of bore, in same number of lines as sections made. Its radial & axial repetitive accuracy range is better if part size vary somewhat.
Interior shoulder could control part length, if stop is employed. If the collet has an exterior shoulder, that qualifies as a stop too.
BTW, tailpipe expanders are good starting basis for a spindle bore stop. Most times, I make a plug; bored slighty larger than stock being run. It should be longer than spindle diameter to not cock in the spindle. Then it butts against tailpipe expander. A real long rod of material might want a bushing midway.

[theeddies]

Ah, ok, I think I got it. Now you have sent me down a rabbit hole of collet theory (that's a good thing). This application is pretty simple with low accuracy necessary, I guess technically it is just soft jaws rather than an accurate collet, but I have something else I am working on where your idea fits perfectly. That is why I share on here because sometimes you actually connect with people who know their stuff. Thanks!

[Toolmaker51]

A lot of sharing goes on at HMT.net. A big portion of that is terminology related.
Calling it soft jaws or a collet isn't wrong, many other terms fit too. If you wanted to order one, it might be called a 'split body soft workholding bushing' in a catalog. English has a circuitous nature, all of us in tow. A safe bet; most here think we share design ideas, but there is an equal amount of vocabulary exchange.

[theeddies]

I can certainly see your point about terminology. Every industry has its own language. There is a constant search for precision in all things, I suppose. A search of your catalog word also brought me to "split holding bushings", "clamping sleeves", "Longitudinally-split sleeves", "Workpiece gripping bushing" and many others as well many variations of collets. I often have trouble titling videos because I am trying to capture terms that are explanatory, searchable, common, fitting to the content, and of course interesting. There are a lot of variables but I really just want to say "here's a tool you might find useful, check it out".
All the best!