Lately I've been considering buying a 1-1.5hp vfd air cooled spindle to use as a motor for my X2 Mini Mill. I have the Little Machine Shop Belt Drive kit, and I'm thinking I could work up an aluminum mount for the VFD spindle, then turn a pulley that would mount to a piece of steel rod in whatever collet the spindle comes with. The reason for doing this instead of just boring out the head and mounting the VFD inside is that I am using the Tormach Tooling System and I really like it for its potential to let me add an ATC.
My question is, am I under thinking this? Any crucial bits I'm missing? Of course I would have to upgrade the bearings on the stock R8 Spindle and maybe limit the top speeds a bit, but I could gain tons of power for $300-400 if it panned out.
Thanks for any advice you can provide.