Brand new to CNC here. I built a Sainsmart 3018 CNC today, and on initial testing it appears the spindle does not work. Perhaps there is something I am missing, but all the steppers are working OK, tested with the offline controller. When I push the spindle start button, the spindle briefly jerks, then a whining sound is heard, almost like a small piezo alarm.
Any idea what could be wrong? I am eventually planning on going the CNCJS route through Raspberry Pi, but if this thing isn't working with the controller that came with it that's pretty concerning.