Create A axis from HV6

I need to make an A-axis to mill some splines. I have an unused HV-6
rotary table which looks good enough for what I need. Has anybody on
the list converted a rotary table like this?

Any ideas on the minimum stepper size to use? I have a spare 34 but it
seems like overkill.

In manual use there are a couple of clamps to improve rigidity when
machining. Is is worth trying to make a clamp system? Maybe a basic
permanent friction brake would serve here? If I am using a large motor
then the drag should not affect the motion.


Regards

David