Control treadmill motor from picaxe


Senior Member

I have a tentative plan to build a 'single axis cnc' type of machine, using a salvaged treadmill motor (probably) to drive an M24 threaded rod to move a heavy object up to +-450mm, with a simple (hopefully) hall effect revcounter to give 'distance travelled' feedback to the picaxe; the resolution wouldn't need to be any more than 1 rev, and it wouldn't matter if the motor span a few turns extra after being switched off (which would be unlikely actually, as the machine would be operating under loads of maybe <=100kg.) There would be no need for any holding torque. A picaxe handling the motor drive etc would communicate with a PC running the software to operate the machine.

The picaxe would drive the motor at variable speeds, forward and reverse, as set in PC software, and also pick up the signal from a load cell to read off the weight being carried, pass that value to the PC, and alert the PC when a predetermined number of revolutions of the leadscrew have occurred.

It's basically a device to move heavy things into and out of the scanning area of a Kinect based 3d scanner. It'll have a turntable on top, which may stay as manually controlled, for various reasons.

What would my (hardware) options be for controlling a 2 1/4hp treadmill motor from a picaxe, with speeds from 0 - @2500rpm, with bidirectionalility? I'm guessing a large H-bridge motor controller. Or maybe, as the motor would always come to a complete stop before reversing, a DPDT reversing relay with a big MOSFET plus some other type of speed control?

Hopefully this is within the scope of this forum, and doable generally...



Senior Member
There are a lot of parts here - do you have a motor and a controller which used to control it? Is it a brushed AC/DC motor?What voltages do you need? How fast do you need to turn lead screw and with what torque? Etc. Take a look at Ebay 'motor controller'... on the mundane side you'll need to isolate your logic unit and sense pickups from electronic noise from the big motor... Perhaps move the Kinect instead of what it is scanning... ;-0