Reducing the space in my garage.

[irving2008]

If your drivers can take it go for the higher voltage as this translates directly to upper speed limit. Current requirement is typically 60% of motor rating, so.60% x 3 x 4.2 is 8A approx. This means you can get away with smaller capacitors .1 x 8/70 is approx 12000uF @ 100v, ripple rating can be lower at around 4A.

Re BOB, correct only 5v for signalling and 24v for limit/home switches needed. All i/o should be opto-isolated at the BOB for inputs and at drivers for motion control step/direction or relay outputs for other controls.