Sawmill with robotic control - need a little help

Hello Group, have a small question about a motor controller set up.

I have a commercial gas powered sawmill (can make 30 inch wide cuts) that I have automated using quantum PMDC wheel chair motors. The motors are 24vdc powered through a 24vdc 20 amp power supply. They run great and have a ton of torque (more than enough for what I need).

The problem is the speed controller. I have burned up 4 amazon junker speed controls in the last week. I figure I just need to spend the money on a controller that is just going to work for more than an hour.

I would like to use a sabertooth 32a and arduino but I want local control trough a panel on the operating station of the mill. I need to be able to control speed of the motors through a knob as well as reverse them when the saw finishes its cut. I just need someone to point me in the right direction on what to buy and if this is even possible using this setup. Admittedly, I’m pretty new to electronic control but I can do anything mechanically.

Willing to take any suggestions, thanks!

Pololu has a good line of high power DC motor drivers.

You need to make sure that the driver and power supply can handle the stall current of the motor. The motor will pull the stall current, briefly, every time that it is startded.

My power supply is limited to 20 amps at 24vdc. It’s the biggest one I could find without spending a ton of money or going to full battery control.

The motor is rated for 200 watts continuous and 1200 watt Max.

The motors are quantum q6 wheel chair motors with gear reduction.

Why is that?

Please refrain from profanity.


It sounds like you have not sourced the controllers correctly in relationship to the torque used and the current required.

To do that you need at lease a basic grounding in applied mechanics and electrical theory.

I would suggest going back to the drawing board and starting with the motor specifications.

That you got this far is a testament to tenacity but seems to have left some basic things out of the overall equation.


Thank you for the informed and reasonable response Bob, it’s too bad everybody here isn’t as reasonable.

This is a probable sawmill. It isn’t in a production plant. I cut wood for use on my land and barns.

I appreciate the response but I do not feel very welcome here. Came to learn and was merely berated for my questions. I’ll take my time elsewhere. Thanks

ocitsalocs: Came to learn and was merely berated for my questions

I don't see any evidence that you were berated for your questions.

I do see that people were reluctant to provide advice for a project that could be extraordinarily dangerous - and to me that seems a reasonable attitude and I have expressed a similar reluctance in several other Threads in the past few years.


I removed a couple of items Robin.

These comments are not a criticism of your design or implementation, but to help with your redesign. Since you have come to the Arduino forum, that tells me you have relied on the advertised or name plate specifications for your devices. These are ALL peak values useful for very short time periods. Very few seconds. Even your wheel chair motors are rated for the peak demand for just a few seconds.

But you are using all the devices in a "continuous commercial" environment.

Look to power your motors using only a transformer and a full-wave bridge rectifier. They do not need a "power supply", such as you have mentioned. If your future speed controller uses mosfets, they don't care if they get pure DC or pulsing DC.

If you look for speed controllers for continuous commercial use, look for ones with about 10X the peak that your current devices are rated for. They will always have very visible heat sinks.

Good luck.


Maybe you could get some of the original speed controllers for the wheel chair motors.