Pololu's Micro Metal Gearmotors

Hi! I have a couple of questions. I’m planning to build a balancing bot, and was looking at the Micro Metal Gearmotors, as they seem to have plenty of torque and rpm.

I was wondering whether these motors are suitable for “instant reverse”, which the robot would require for balancing. Does anybody know?

Secondly, has anyone built an encoder for use with these motors? How many counts per revolution did you manage?



We haven’t specifically tested the motors for your kind of application, but we’ve been using them in our 3pi robots. The original prototype bots have gotten quite a bit of use and abuse, and the motors still seem fine. We’re also stressing them extra hard with the high-voltage drive we’re using, so I would expect them to hold up well in your application at a more normal voltage (around 6 V).

That’s just with the lower-current motors, though; the high-power units are nice but will stress everything more.

Do you know what you’re using for sensors? We’ll be coming out with a new gyro carrier in the next month or so. Keep us posted on how your project goes!

- Jan

Hi Jan,

Thanks for your reply. I was thinking about going for the 210:1 HP Micro Metal gearmotor. I’m not planning to buy anything for another couple of months so will look out for your gyro carrier as I’ll be needing one.

By the way, do you know how I could fit a reasonably high-res encoder (that works reliably) on any of your gearmotor / wheel combos? (I’m looking for 100 cpr or more)