I am looking for a gear motor to turn a 9-pound spool of string. Ideally, I want enough torque to turn at low rpm (ie. 1, 5, 10). I’ve got the system to turn with a 303 rpm motor with 16.8 oz-in of torque (ROB-12147), but the movement needs to be kick started externally. From Sparkfun’s inventory, similar motors increase in torque as rpm decreases. Which of the other gear motors should I order to be certain it can turn the 9-pound load at a low rpm?
I should also add that this motor needs to run for 7 hours a day, 7 days a week. The current motor is running off of an Arduino, 12V power supply, and L298N motor driver board.
Hi pmakin,
For this type of application, I am not sure if SparkFun is going to have a motor that will work under those conditions. If you are having to “kick-start” the motor, that can damage the gearbox since it is technically stalled before then. You could try using one of the lower RPM versions of these gear motors like this [10 RPM Motor but it might be a better option to go with a heavy duty gear motor. Unfortunately, we only carry a single heavy-duty, [planetary gear motor that runs at 140RPM (no load). The manufacturers of the gear motors we carry, ServoCity, has a wider selection of heavy duty motors that should work better for this project.](https://www.sparkfun.com/products/15277)](https://www.sparkfun.com/products/12367)