"BobMac" wrote: (clip) When I mount it in the tailstock, it just spins
freely, (clip)?
^^^^^^^^^^^^^^^^^
You have something like a Jacobs chuck on a live center. That's really
weird, and should not even exist. Take it back where you got it and ask
them what the h... is going on. They should take it back and give you
something that makes sense, i.e., a Jacobs chuck solidly supported on a
Morse taper (no rotation.)

I would be really intrigued with their explanation. Or did you put this
together yourself, out of pieces that were meant for other uses. A Jacobs
chuck usually mounts on a Jacobs taper. Possibly you got hold of a Morse
taper with a live center that takes interchangeable tips. If these attach
by means of a Jacobs taper, I can see how you could possibly put together
the useless combination you have.