Just starting to configure a new build.  This is first with dual spindles.  I am not sure how to set this up and how to control the 2 VFDs.  I have the 7737 step/direction boards with closed loop for the 6A motion.  Was thinking I could use the other 2 available step/dir outputs to run each spindle as an OB motor - or maybe one on the 0-10V the 2nd as an OB motor.

How would I set this up, and how would I control each spindle?  I plan on having separate M codes for each spindle on - say M13 for spindle 1 on clockwise and M23 for spindle 2 on clockwise.  Trying to determine how to control  how the S values go to the correct motor.  I haven't had any issue setting up a single spindle in the past, just can't quite figure out how to set up the 2nd one.

You can connect both the spindles to the 0-10v and use one of the relays to switch between the spindles.

You cannot run two spindles simultaneously at different speeds. Must be both at same speed or would have to switch between them.

Thanks for the reply.  That makes sense.  It was one of the ideas I had but was really hoping to be able to run them simultaneously at different speeds but I can work around running them both at the same speed.

I assume I only need to set up a single spindle in Mach4 then just use the separate M codes to control on/off of each spindle with the shared 0-10V.