Nice Little $1.50 DC Gearmotors
Dangit, I had a nice long post that got deleted from some stupid posting glitch. Brief synopsis:
Bought ten, like 'em, ordered ten more. Five for $7.66: http://www.ebay.com/itm/131322641237
SLOW, low current, seems pretty efficient when I backdrive it. Unusual form factor with a flat pancake motor. Ebay description says 6-12V, but my plan is to use these at ~4V, where no load is ~17 mA, 14 RPM, 51 mA stall. Glue-friendly ABS housing, plenty of lube inside (see pic), not much backlash. May use these as Trike bot drive motors for class. No reverse needed, just a mosfet for PWM and a steering servo. Won't win any races, but good slow speed control. Could use a wheel as small as 3/4" diameter with sufficient ground clearance.
I prefer this too-slow motor to this squirrely, same-price too-fast 1:48 gearmotor: http://www.ebay.com/itm/1pcs-TT-Anti-interference-f-Robot-Auto-Chassis-Motor-Geared-DIY-DC3V-6V-NEW-/161668491655
EDIT: Also received these $2 gearmotors today. Glacially slow double-worm. Plenty of lube, surprisingly torquey. could be used as a light-duty robot arm joint. Might be the same pancake motor as on the first one mentioned here. http://www.ebay.com/itm/311250697134 Internal pic at http://i.ebayimg.com/00/s/MTIwMFgxMjAw/z/yiMAAOSwxYxUsK7i/$_57.JPG
Bought ten, like 'em, ordered ten more. Five for $7.66: http://www.ebay.com/itm/131322641237
SLOW, low current, seems pretty efficient when I backdrive it. Unusual form factor with a flat pancake motor. Ebay description says 6-12V, but my plan is to use these at ~4V, where no load is ~17 mA, 14 RPM, 51 mA stall. Glue-friendly ABS housing, plenty of lube inside (see pic), not much backlash. May use these as Trike bot drive motors for class. No reverse needed, just a mosfet for PWM and a steering servo. Won't win any races, but good slow speed control. Could use a wheel as small as 3/4" diameter with sufficient ground clearance.
I prefer this too-slow motor to this squirrely, same-price too-fast 1:48 gearmotor: http://www.ebay.com/itm/1pcs-TT-Anti-interference-f-Robot-Auto-Chassis-Motor-Geared-DIY-DC3V-6V-NEW-/161668491655
EDIT: Also received these $2 gearmotors today. Glacially slow double-worm. Plenty of lube, surprisingly torquey. could be used as a light-duty robot arm joint. Might be the same pancake motor as on the first one mentioned here. http://www.ebay.com/itm/311250697134 Internal pic at http://i.ebayimg.com/00/s/MTIwMFgxMjAw/z/yiMAAOSwxYxUsK7i/$_57.JPG
950 x 750 - 208K