pwm dc motor drivers- h-bridge

[visky]

are PWM motor amplifiers good for cnc machines?

Many of you buid simple h-bridge circuit for driveing dc brush motors.

How it is with motor power at low speeds 1-100rpm and torque?

Has it got power and torque or it can be stopped easily with hand?

[epineh]

They work fine so long as the control loop is tuned correctly, I am setting up servo's with DIY drivers (Elm Chan and DSPIC) and I am surprised at the power, at hold (dead stop) I can't move the shaft by hand, motors are fairly small, 24V probably about 150W (no specs with motors - old second hand ones )

You will need to tune the drivers though, they were a little "spongy" to start with, now they are very responsive.

Russell.