Difference between planetary and precision gear motors

Question

i'm working on a building a rover and would like some advice on selecting motors. In particular, i want to understand the difference between precision and planetary gear motors. My robot will way about 10-15lbs i think and would like it to be responsive and quick. I have two sabertooth 2x12 motor controllers (which can supply up to 12amps). I have been looking at these motors and i am not sure which is better choice for my application.

These are the two sets of motors i am thinking about. https://www.servocity.com/html/precision_robotzone_gear_motor.html https://www.servocity.com/html/3-12v_precision_planetary_gear.html

googling does provide some info on planetary gears, but the application of these two is still is unclear to me.

Thanks

Answer 1

"Precision motors" and "planetary gear motors" aren't really describing the same attribute of the motor. It's like comparing "fine-point pencils" to "red pencils" -- they could be both fine-point and red, either fine-point or red, or neither.

Planetary gears are generally used to convert high RPM at low torque to low RPM at high torque. Because each rotation of the motor shaft results in a very small movement of the gear system's output shaft, you could also say that planetary gears offer you very fine precision in the output. It's unclear from these links whether that's the case (and it's possible that both of them are using planetary gears).

Perhaps "precision" is just being used a marketing term. Are there specific requirements you have for your motors that aren't being shown in these listings?