Lathe AC servo spindle motor

Hi everyone. I have made a CNC lathe which works very well, thanks to a lot of help from this group. It currently uses a 3 phase AC motor with a VFD. It only goes forward but I can control the speed in the software and gcode. I am rebuilding the machine, making it stronger and heavier and want to change the motor so I can do forward and reverse, as well and position. I understand it would be setup as C axis like the commercial lathes, but was wondering if anyone has done this, and if its even possible. I am looking at some AC servo motors on Ebay, like this one -

AC20V~80V HSS86 Hybrid Servo Driver + NEMA34 Closed-Loop High Speed Stepper Servo Motor 8N.m 0~3000RPM

Any ideas or suggestions? The reason for the position requirement, is in the very near future I will be adding either live tooling or a Y axis to mill. It is mainly small parts in brass, bronze or aluminium.

Thanks and hope someone can assist. This group is really great.

hi a setup like in this video
its on his page

Hi. Exactly what I would like. Do you do the setup? The link on your YouTube page doesn't work unfortunately

if you got a YT account write him
there is also a homepage with Mail to get direct contact

he is also here in the Forum
with his name

Assuming you want to be able to run the spindle at full servo speed, and also want to be able to mill-turn, you will need rather a lot of torque.

For a given material, cut depth, tool size and work diameter it should be possible to calculate the required motor torque using one of the feeds and speeds calculators (I know that the FSWizard app, at least, calculates cutting force)

I rather like the idea of using vehicle air-conditioner clutches to swap between two belt ratios for this sort of application. They are rated for about 30Nm.