I can fully understand that, but the diagram is in my head, however its currently like this basically...

1 - I have an 11A smps connected to the three motor drives,

2 - a smaller 24v smps connected to the BOB,

3 - The BOB is a cnc4you.co.uk HG07 unit - Breakout board CNC Stepper Motor 5 Axis Spindle Relay HG08
Ok Dave what is the o/p voltage from the 11A p/s. It states on their data sheet that when using a plasma you have to use a separate p/s for the BOB (that is normal anyway).
re this (They also said it was wired wrongly, I had the BOB supply fed from the Z-axis output of the main PSU) if that is the case what is the purpose of the smaller 24V p/s connect to the BOB

In my humble opinion smps are crap for motors and you would have been better off with a toroidal type none regulated.


Don't get despondent there are enough people on here to help out if you give the information that is required ..Clive