I am a beginner in Electronics and motors, and I want to build a DIY device that is like this


I am just wondering how powerful is that motor that turns the globe in the device, which would hold the cat waste and litter. I am looking to get a powerful enough motor from Amazon.ca but just not sure how powerful do I need to go. I think I am looking for AC motors as they are more powerful than DC.

Does anyone know?

enter image description here

  • 1
    $\begingroup$ Tip: post enough information (a static image, for example) in your question that it can be answered without reference to external links which may die. Not many of us are going to watch a video for you. Both AC and DC motors' power are specified in watts and can be made pretty much any size. AC induction motors are simpler so most large motors are of this type. $\endgroup$
    – Transistor
    Dec 31, 2022 at 18:50
  • $\begingroup$ ok I added a picture $\endgroup$
    – omega
    Dec 31, 2022 at 18:56
  • $\begingroup$ the motor is powerful enough so that it does not stall during normal operation $\endgroup$
    – jsotola
    Dec 31, 2022 at 19:00
  • 1
    $\begingroup$ looking to get a powerful enough motor ... to do what? $\endgroup$
    – jsotola
    Dec 31, 2022 at 19:01
  • $\begingroup$ Turn the barrel $\endgroup$
    – omega
    Dec 31, 2022 at 20:07

1 Answer 1


Variations of this get asked all the time, and the fact is that it's very difficult to quantify factors such as friction. If you use basic physics to determine the torque required you will get an extremely low number, that will not work in practice.

You can either build the drum mechanism first and then measure it. Or, the more practical approach which is to basically guess if you had a lever of a certain length attached to it, how many kg would you have to apply to the lever to turn the drum?

An example of a reasonable guess might be 2kg at the end of a 30cm lever. That's 20 newtons * .3m = 6nm torque.

It's better to buy a motor that's slightly too strong, rather than one that's too weak that has to be replaced, so lets double that estimate to 12nm torque.

Keep in mind that "powerful" is not what you need. Power is rated in watts, and more power allows you accelerate the drum faster and reach higher top speeds. You likely don't care about this. What you care about is the ability to turn the drum at all, and that's a matter of torque.

Case and point, a very tiny motor the size of your thumb with a large gear reduction will be able to turn this, it will just turn slowly. A huge motor the size of your fist with no gearbox might struggle.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.