This listing is for the motor shown, a 4 horsepower 220 volt DC motor. I removed it from a treadmill. Also included will be the speed controller from the treadmill. It has been slightly modified.

As shown in the pictures I found a place to grab a lower voltage and added a buck converter to supply 5V to an Arduino Pro Mini. That Arduino sends a PWM signal to the main board proportional to the position of the potentiometer attached to it. The main board is then able to control the speed of the motor by turning the potentiometer.

I have tested it by feeding it common household 110V through the onboard bridge rectifier, like it was in the treadmill. I have also powered the board directly from a Toyota Prius battery sitting at around 208V. I put the whole setup on a go kart and just wasn't happy with the power for my uses.