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Subject: RE: [Homebrew_PCBs] dental handpieces for copper clad drilling

From: "Tony Smith" <ajsmith1968@...>
Date: 2013-02-05

> Dentist bits are 1/16". PCB drill bit shanks are 1/8". So you have to
insert a 1/8"
> diameter shank into a 1/16" hole. Does the ER collet accommodate this?


You can't mix & match sizes, 1/16th bits in 1/16th collets, and 1/8th bits
in 1/8th collets.

Seems obvious, but using the wrong size means it doesn't grip properly.
Damages the collet too. ER16 goes down to 1/32th, IIRC.

You can use a 1/16th bit in a 1/8th collect (dentist bit in a Dremel) by
slipping a piece of tube (maybe with a slit in it) over the bit to make up
the different, that's what 'Boot's was referring to as the reducer, though I
think he missed you're going the opposite way.

The only way to use 1/8th bits in a dentist handset is to replace the
collet. Someone with a lathe could make one for you easily enough, boring
out an existing collet to 1/8th might be possible, but they're usually
hardened. Well, good ones are.

You can get what's called an 'emergency collet', basically a blank you drill
out to the correct size.

Tony