I currently have mach3 set up using 4 motors X,Y, Z and slave the Y using the A axis. I want to include a 4th axis i.e. rotary positioner . I guess I have two questions about that.

Q1: Can I use the B axis as an alternative to A axis

Q2: If I reconfigured the controller wiring to run both Y axis motors off the same pins, which would then free up the A axis would that be an advantage? As both Y axis motors currently home separately I find this useful to square the table but could be persuaded to switch to dual Y. 

Within Mach3 you can configure the B axis to be slaved with your Y axis - thus freeing up your A axis for rotary working.

It is not recommended to connect two axis (motor drivers) to the same pin.

Tweakie.

Within Mach3 you can configure the B axis to be slaved with your Y axis - thus freeing up your A axis for rotary working.

It is not recommended to connect two axis (motor drivers) to the same pin.

Tweakie.

Thanks 4 reply. I set up the B axis to be slaved with the Y axis. I was just trying to keep B free for when I build a B/A head.

Just out of interest why is it not recommended to connect two axis (motor drivers) to the same pin?

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Just out of interest why is it not recommended to connect two axis (motor drivers) to the same pin?

why you do not have a chance to square the axis by homing