which type of motor wold you recommend?

Hello, I plan on making a big automatic sliding door using wheels and a pulley system. The door may weigh from 10-15 pounds or so. I know I will need a "High torque" motor, but how do I tell whether it will be enough power to suit my needs? do you think a stepper motor would work best for this type of project? Other than that, I have a good idea f how I will achieve this using arduino. Thank you in advance!

You need to measure the force required to move the door, and set up a mechanical arrangement such that a motor with sufficient torque can provide that force.

You could use a luggage scale to measure the force. For an introduction to force and torque, see this blog article.

Then choose an appropriate brushed DC motor and motor driver, keeping in mind that you can trade motor torque for speed with a gearbox.

thanks alot, this is just what i needed to get started

I have used auto window motors several times to move large loads.
You should be able to get surplus motors like that for only $8.00.


This is an application where a stepper motor is bad news. Stepper motors exert maximum torque at
low speed, potentially creating a crush-injury hazzard.

You want a standard DC motor with the torque limited (ie current limited), so that if the door is
blocked it doesn't:

  1. physically damage the mechanism
  2. damage anybody caught in it
  3. burn out the motor

To calculate torque you need to understand the basics of mechanics, or else provide full details of
the gearing/belts/etc so we can calculate that for you.