thanks - today, I was rearranging tooling and low and behold I have a self
centering (floating) collet chuck thingie - it is for taps - it has a tap
collet (with the square bottom) and a 3/4 inch shank - But, I don't see a
convenient way to use it to hold anything except taps, and I only have the
one collet (1/4) for it - it doesn't look like it could hold anything much
larger. So, I moved it from its previous hiding place to a new hiding
place near the taps, so at least if I need it, I have some small chance
of finding it.

next step is to figure out which size ER collets I have - maybe
tomorrow.... Meanwhile, I am learning something from this thread - perhaps
some others are also.

I went out to the garage to see what collets I used with the Mill - it turns
out I have two holders, one that is NMTB to R8 and so I can use R8 collets,
and one that is this one
http://www.dealtime.com/xPO-Valenite...et-Holder-X634
which apparently uses TG-100 collets (I have a range of collets for it)
And, of course, I have 5C collets for the lathe
so, now to see what I can find.....

suggestions?