Motor with return

Help & Support Robot Parts
1

Hi. I am hoping that someone can point me in the right direction. I’m looking to buy a motor that I can use for a prop.

I know things are all relative, but the motor requirements are:

  1. Light weight
  2. enough torque to pull something around on a hinge.
  3. Low RPM (like 10rpm)
  4. Returns to the neutral position when it is no longer active.

#4 above has been hard. I started using windshield wiper motors because they have a park feature. But they are heavy. If there is a better option, I’m game. The motor only needs to be off and on. I don’t need something like an Arduino servo - well I probably do but I have a deadline fast approaching and I don’t know how to build that out in time while learning.

I build props, not robots so please excuse my ignorance if this is a simple question.

2

Can you clarify #4? Does it need to return to a specific angle? If so, how were you able to get a windshield wiper to do this? Considerations include:

]Servo motor: you can position them, but they can’t do continuous rotation/:m]
]Stepper motor: They have relative positioning, not absolute/:m]
]DC gear motor with encoder: Relative positioning, not absolute/:m]
]Smart servo: absolute positioning, continuous rotation, but require programming/:m]
Your best option is a smart servo, but it’s also the one which needs to be connected to a microcontroller and programmed.

3

Here is a pretty good video explaining the wiper motor park feature.
youtube.com/watch?v=1Ww5-pmiokc

I may end up using a wiper motor but its overkill and of course its heavy. The application of this will be pulling on a lever to make a sort of jointed arm move inward. But when its not active, it needs to be in its outward position. I can get it there with some tension wire/springs but need the motor to allow it. If you put an arm on the wiper motor it will pull on its backswing and release with its sent home.

4

Quite a unique application. In the video, they don’t seem to cover how the switch is triggered (programming or physical?)
If you can do that with a wiper motor, then you should be able to do it with a smaller DC gear motor.