NW 3pcs 3V Micro Planetary Reducer Motor High Torque DC Motor DIY Robot Gearbox Motor (9161A)

Excellent little motor. Well built, and lots of torque. I have a little concern about the fact that it's only supposed to be rated for 2.5 volts according to their specs, but they give voltage vs. RPM measurements all the way up to 5 volts.180 RPM is perfect for my application, so I'm hoping that driving it at 5 volts won't shorten its lifespan too much. Regardless, this is a great little motor.

Very good motors

These motors have a lot of torque for their size. They are pretty durable to. Great product for a great price.

Perfect size to incorporate into my projects.

I was looking for a way to replace the bulk of a SG90 servo and I think I found it. These appear to be the same motors that are in SG90s, and they're geared down very well. I can't turn the grey gear by hand, which is a very good thing. My rough measurement from a lithium ion battery suggests 156 RPM on the grey output gear (~3 volts). The output gear on the head is 11-tooth, approximately 6mm diameter. I had no trouble making a 3D-printed attachment for it (compared to most servos gearheads that have a significantly smaller pitch and higher tooth count). Great for small things where a servo isn't necessarily required.