Simple Current Limiter (LM317)

[BillTodd]

Will adding reverse protection diodes across the current limiters cancel this out.

No. When you run the motors there's a likely hood of generating large back emf from the stepper coils the diodes are to stop this damaging the LM317s.

That looks like a normal rectified transformer output. Ripple is, what?, 3v - perhaps a bit high for a few amps of load. What size (VA) transformer and smoothing cap?

[Mad Professor]

The power supply I am using is out of a fruit machine, and is a Barcrest MPU-LF Transformer & Power Supply, that is as much as I know.

This power supply has multiple outputs, I am only using one output marked at 34VDC @ 7A.

The smoothing cap inside the power supply for the 34VDC rail is a 4700uf 80wv.