Unbalanced motor output
October 2, 2010
Ok, so I've got these cheap motors in the DFRobots 2WD chasis that are so unbalanced that the thing almost spins in a circle! I've been searching the forums and it seems like everybody's using PWM to adjust the motor output, so I've been trying to adjust mine that way. Problem is, I can get it just about balanced at a higher speed but then it's totally off at a lower speed. And it got me thinking about "why" the motors are unbalanced. Is there some kind of electrical imbalance within the motor that's causing it to run at different speeds with (presumably) the same input voltage? For example, I know that guitar pickups in the 50's sometimes had a drastically different number of turns for the winding of the electromagnet, causing some pickups to be "hotter" than others. Is it possible that motors could have a different number of windings causing some to run faster or slower? And if so, could we compensate with resistors or a trim pot to bring the motors more in line with each other? I'm just thinking out loud, hoping someone has a good idea. My concept is that my bot will have a relatively high "cruising" speed but will drop down to a lower speed when the sonar shows it's approaching an obstacle. With my motors the way they are, the trim goes all to heck when the speed changes.