5c soft collets

[Allen Smithee]

Can anyone tell me how wide the slits are in a 5c collet? I'm thinking specifically of a nylon "emergency" collet like these. A friend needs a jig to hold thin sheet metal arrow fletchings accurately while the adhesive cures, and it occured to me that if the slits are wide enough it would be very quick and easy to machine one out of one of these nylon collets. I think his fletchings are from 20thou sheet.

TIA,

AS

[Lew Hartswick]

It seems strange that the people who sell those machinable collects don't also sell the spacers that fit the slots that are required while doing the machining.  That should be an OBVIOUS thing to any "Marketing idiot" . :-)
   ...lew...

[Jasonb]

The nylon ones tend to come with partial slots so you don't need packing to machine them though a few use pins and the steel and brass are also supplied with packers, if you happen to loose them I'm sure most shops hace a few bits of 1/8" rod to go in the packing holes.

I can stuff 1.4mm of feeler gauges into my steel collets if that helps.

[rklopp]

The nylon emergency collets I have take 1/8" thick ground flat stock ("gauge plate") in the slits as props while I machine the bores. You would not want to try boring one without support in the slits and the collet snugged up. On my lathe, I have to be careful with spindle acceleration when using plastic collets, lest the collet handwheel self-loosen due to its inertia. Fortunately, I have electronic speed control, and can simply dial down the potentiometer knob.