pwm schematic help required please?

[Tel 27]

If you're using control via an external controller, likely it'll be best to ditch the pot as it could interfere with the settings (if not set it to mid position where it'll have least effect) . Normally you'd connect the 0...10V output to where the wiper connection of the pot connects and ground to the anti-clockwise connection: unless there's a separate input for external control. What driver board is being used for the spindle?? I've investigated a little bit about such things as I'm in the process of converting my pillar drill to a similar DC motor.

I've attached (or at least tried to) a pic of the motor controller board (any help identifying it appreciated)

The problem is I have no electrical diagram or means of identifying the board to ascertain how it works.

There's 240v ac in and dc out, then there's a ribbon lead which was previously (incorrectly I think) wired to a potentiometer.

When powered up via mach3, the 4 wires on the ribbon lead measure as follows:

wire 1 has 5v across wire 4
wire 2 has 5v across wire 4
wire 3 varies but when switched off slowly loses voltage so assume that is capacitor on the board?
wire 4 see wires 1 & 2

The spindle only spins (to 2800 rpm) when wires 3 & 4 are connected, no other connections have that effect, wiring the potentiometer in allows the spindle to be slowed manually.

I've tried various permutations, but cant get the pwm wires from the breakout board to have any effect on rpm?

Any ideas?