Thanks for your response. The wiring is all correct as the spindle spools up smoothly as before but seems to top out at a lower RPM. For further info, the wiring was about 1.2m in length, now extended to about 2.5m.

I lack some electrical knowledge. Which pins on the speed controller should I measure between to get the voltage reading mentioned above. And should it result in being lower than the 10v suggested, how would I go about boosting it? The speed controller itself is supplied with 48v.

Many thanks,