Looking at the drawings of NMTB 30, CAT 30, BT30, looks like they would all
work in an NMTB spindle with the appropriate drawbar. I've mostly looked at
the internal taper dimensions, not sure about the drive keys fitting all.

I was thinking about getting a pull stud style CAT or BT 30 toolholder and
seeing if I can make a spring loaded pull stud drawbar for it. If not, I
would at least like to be able to use it with a threaded drawbar.

RogerN