Ignoramus26677 fired this volley in
:

Are your holders QC-30?

yep.

There seems to still be a decent supply of American made old and NOS
holders out there (but a bit pricey), and there are some nicely-made
Taiwanese clones available for cheap. But right now, I'm spending my
money on other things.

LLoyd
PS(it would be nice to build a tool-changer, too, but I don't know if
that's beyond my skills)
LS