Ok I decided to convert my 6 inch indexer (42:1) from to CNC-able unit. I already have a 2hp mill converted and now need my 4th axis to be able to work in tandem with XYZ as well as independently (e.g. I would like to set its speed and let XYZ work as though 4th axis doesnt exist to use my mill as lathe)

I already have appropriate PS and frequency generator for independent operation.

Questions.

0. What electronic components would I need to get what I want?

1. What motor + electronic guts do you recommend to spool my indexer. Where to get it?

2. I am concerned about a backlash. My indexer has adjustable BL but if I set it tight (as would be needed by CNC ops) I can hardly spin it by hand. Is it normal?

3. What is the reasonable max speed of continuous rotation (rev/min) can I expect keeping in mind that indexers are not made for continuous rotation and it may be hard on worms. Should I consider extra lubrication?