Denford Software & Machines

Hi all, been trawling through the forum but I've a teeny question re the sprint board on my Novamill.
I've got the mill working from LinuxCNC, everything done bar spindle speed control.
I have a generic BOB from ebay, have rigged up it's relay to the Sprint (pins 5 RUN and 6 COM) - to run the spindle, all works ok, and I can set spindle speed with a 10k pot on pins 1,2 and 3 of the Sprint. I'm also getting a 0-10V output from the BOB, but I'm hesitant to connect the BOB and the Sprint, as it's input pins are at mains voltage. The BOB is getting 24v from the Novamill 24v supply, and so it's ground is chassis ground. So it seems things might go bang if I connect the BOB GND & 0-10v output to the Sprint's MIN and I/P (pins 2 and 3)??
Another question might be - how can I get chassis ground and 10v output to a floating output to feed the Sprint?

It depends on your BOB.

Better ones will have the 0-10V circuitry isolated, provided you use an isolated supply (usually requires 12V), which is easily done with a DC to DC isolating supply.
And some will have an isolating supply on board.

Have you got a link to the BOB you're using?

the BOB is one of these:
https://www.ebay.co.uk/itm/5-axis-CNC-B ... SwbP1aZvGa
Seems the GND is common throughout the board, including the 5v input (which I'm taking from the Baldor 96 pin) and the 24v input. Hmmmm.... so an isolated supply would still end up with -ve at chassis ground.
I did buy one of these:
https://www.ebay.co.uk/itm/1-3KHZ-to-0- ... 2749.l2649
Which might be a solution if it has it's own isolated supply, and fed from the BOB...??