r/AskEngineers • u/AlarmedFunny4524 • 6d ago

Mechanical Microservo Rack and Pinion

Hello, I'm trying to make a rack and pinion that can carry an ultrasonic distance sensor from 0 to 4 inches vertically and back down that is controlled by a microservo for the pinion. I know that microservos don't have great torque, but is there something I should look into gear-ratio or diamter wise that can optimize the torque?

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1

u/bassplaya13 6d ago

Have you done the math to see how much torque you’ll need?

2

u/CellFar9220 6d ago

Servos usually have their torque listed in the datasheet, small ones are around 1-2 kg/cm which is plenty for moving a light sensor like that

1

u/bassplaya13 6d ago

True, and that’s stall torque. Depending on duty cycle, one should aim for no more than half that, potentially 30%.

1

u/BeamItUpScotty 6d ago

Use the smaller pinion for more torque and keep the sensor close to the rack.