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Tech Forum

May/June 2018

Proper Motor Selection

I need some tips on selecting motors for an art project that continously rotates five different circular platforms (10” diameter, 15 lbs) 360° in one direction, then in the reverse direction. The complete rotation of each platform should take approx 30-40 seconds (not critical). A direct drive approach would be preferred (seems simpler), but I could use a gear reduction scheme if it were more cost-effective.

Caitlin Russell
Stony Creek, VA


Because you say the load is 35 lbs, you probably need a heavy duty drive with bearings to support it. While the unit listed below is expensive, $180 USD, it will do the job.

  1. Speed can be slowed by reducing the voltage.
  2. Reversing is done by changing the polarity.


  • RPM 25 RPM @ 99 VDC
  • Voltage 99 VDC nominal
  • Amperage 2.1 Amps @ 99 VDC, No load
  • Gear Ratio 108:1
  • Rotation Reversible
  • Enclosure Totally Enclosed
  • Duty Intermittent

This cheaper motor might also work:

Jim Faulk
Longmont, CO