I need some advice on using a motor for my moving wall model.

Please watch this Reddit video and read my video timestamps:

  • [00:00] Animation showing the movement of the 3 walls.
  • [00:22] Animation focusing only on the orange wall and the supporting rail above it.
  • [00:38] My current model (a dangling tape measure representing the orange wall).
  • [00:54] The model uses 4 pulleys, string and a curtain rail to pull the wall along.

So basically, I would like to turn my manually operated model into an electronic controlled model. I experimented using a potentiometer, a motor and an Arduino but I had some technical issues, there was trouble with the string being able to catch the rotation of the motor.

I spoke with a friend and they said to maybe use a DC motor with teeth and a belt instead of string to get the motor to catch the pulley system. I'm not really sure what sized motor teeth to get or how to attach a belt and will these new components be quite expensive?

Does anyone have advice on what I should do or any other methods?

Thank you!

I think your friend is referring to toothed belts and pulleys, sometimes called "timing belts" (because that's what they're often used for in IC engines etc). Have a look here.

thanks! You pointed me in the right direction for help :slight_smile:

cowabungadood:
thanks! You pointed me in the right direction for help :slight_smile:

Welcome. Bit of Karma would be nice, if you think it's worth it. Thanks in advance :slight_smile: .

Good luck, and keep us updated re. your project.

I'd recommend using rubber+glassfibre belts, not polyurethane+steel belts.

The latter are for high power high force situations and are annoyingly stiff for small models.

MXL is my go-to belt system, there are others.

Belt systems need correct tension to avoid jumping, so you'll probably need to figure out
a way to adjust this. A ball-bearing race between two large washers can serve as an idler
pulley.

String/wire drive can be done, using a drum - you need several turns around the drum to get
sufficient friction, and again tensioning is important. The drum has to be longer the further
the travel is and the thicker the string/wire, as the winding crawls along the drum.

Do not order anything until you know the forces necessary to make your project move as you want.

Paul