Well I've finished the power supply and most of the rest of the wiring for the electrical cabinet, there's just a few wires left to run once I get some connectors for the steppers.

I was just double checking my earthing plan and I came across something I'd not considered before. Should the neutral (DC common) of the secondary be bound to earth at a single point (perhaps with a 1000 ohm resistor in series) to prevent it floating to a high potential above earth?

If you Google for "linear power supply" there seems to be about an even split between circuit diagrams that show neutral bound to earth and those that don't. The only reason I have seen for not doing it is to prevent noise but this is a power supply for steppers there's noise all over the place anyway.

I think I can see where a problem would occur. Without the earth bond on neutral what's to stop the neutral rising to, say, +100V relative to earth as long as the positive is always 70V higher? Having said that my natural aversion to letting the blue smoke out makes me hesitant to connect a cable from the secondary side of the coil to the same earth the primary side is using - I don't properly understand why this can't act as a short.