Originally Posted by miniumwage  I'm working on a x1 cnc. just got my treadmill motor in today, but need to find or built speed controller. Keep me informed on your motor and controller build. |
I'm building my controller around a PIC16F877 microcontroller. The desired rpm is set by turning a pot and displayed on a 4 digit LED display. To sense the spindle speed I will use a sensor like the one I built to do threading on my CNCed Taig lathe: a small magnet on the spindle and a circuit based on a 3503 hall effect sensor to give one pulse per rotation. Actual motor control will be done using the PIC's hardware PWM driving a mosfet. (With an optoinsulator between.) Supply to the mosfet will be 308VDC (220VAC trough a bridge rectifier.) So far I have only tried it with small/low voltage motors and need to get some IRFP460 mosfets, some high speed optoinsulators and a streadmill motor before trying this.