Ever since I first saw a pager motor, I've thought how cool it would be to get a small gearbox to mesh with it. I even have mated pager motors to oven timer units (OTUs) to get good, although large gearboxes.
Well, now we have a much smaller, tighter design with the Solarbotics GM10 pager gearmotor. 81:1 reduction, resulting with 370rpm at 5V with
3.6 in*oz measured stall torque.
They're designed by Mark Tilden for toy applications, and much like his other gearbox designs, they're cool and a bit funky. By default, they have a self-centering spring, so 90 degrees of movement left or right is possible by the polarity of power applied to the motor. Remove the spring, clip off a stop, and you've got a continuous-rotation gear motor!
The output shaft has a square key 0.140 per side. We don't have a wheel for it at this moment, but it looks like a trivial task to mount one to the output arm.
Price? $12USD each, or $9.75/ea USD in 2 or more. MUCH less expensive than hacking a nanoservo to build a custom geartrain!
Thenkyoubeddymuch for your attention!
Regards, Dave