fischertechnik community forum

Hi,

I'm trying to combine 2 of these motors on the same chain, but despite the same speed-setting their actual speed is slightly different. Is this usual ?

hvn

Yes the speed of these kind of actuator is normally different.
You could use the concept of a differential to combine the power of both motors.

Thank you for your response. However, wikipedia says that a differential has 1 input (motor) and 2 outputs (wheels). I want it the other way around: 2 inputs and 1 output.

Hello hvn,

You may well put each of the two motors on, for example, the "output" axles of the fischertechnik differential gear, and use the differential housing as the output. If you attach the motors so that their revolution directions subtract, you get the speed difference on the output. If you attach the motors so that their revolution directions add up to the same output direction, the output will give the mean of the two speeds.

However, you might end up with a more powerful output if you just put both motors on the same gear without a differential gear in between, even if the motors run at slightly different speeds. As soon as there really is work to do at the output, the speed will decrease and both motors will provide to the output power. With a differential gear in between, it may be that the output power is actually less.

Best regards and good luck with your model,
Stefan

Hi steffalk,

Thank you for your response. Will try 2 motors directly then, since I'm missing some parts for a differential drive.