I'm considering building a mount for cameras or telescopes which I would want to move at the rate the Earth spins (i.e., 1/1440 rpm). I've considered using the mechanism for a clock and just using the hour-hand with a 1:2 gear, but from what I've seen, inexpensive clock movements are not made to support any real torque for moving an object with significant inertia.

More generally, what's the best/most economic motor approach to drive a system with significant inertia at very low rpm? Speed needs to be consistent and considerably smooth

Are there any good, economical solutions to this? Ideally I would like to power this with a low-voltage battery pack, so I figure a synchronous motor wouldn't be useful (plus I don't know if they can operate at slow enough speeds).

p.s., this is my first post, so I apologize if there's a better community that I should be posting to.


1 Answer 1


I'm not sure about battery-longevity of any form of motor capable of working at your desired speed and accurately moving a load that presents much back-torque.

However, I think that you may find a "stepper" motor to be a very viable solution for giving accurate, predictable, ultra low-speed motion for your mounts.

While the stepper-motor itself moves in a series of very small "steps" (often up to 1000 steps/revolution), if you combine the stepper motor with sufficient gearing, or a screw-drive mechanism, you can have it "step" at several pulses per second, and have the drivetrain absorb the unevenness of the motor's movement, giving a very stead motion to the camera/telescope in your motorized mount.

  • \$\begingroup\$ i will add my voice to your answer stepper motor with microstepping , and with a low backlash gearbox \$\endgroup\$
    – ElectronS
    Feb 15, 2016 at 11:35

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