Micro metal gearmotor markings


I have a number of different micro metal gearmotors and I’m having a problem keeping track of which is which! They all have a marking which probably identifies the exact specification, but I can’t find any reference which ties these markings to the specification. For instance I recently bought a pair of 10:1 High Powered motors with extended shaft and these carry the marking 181 F3E. Does anybody have a list which ties these markings to the motor specification?



Hello, Chris.

Unfortunately, those markings do not identify the type of gearbox on the motor. The color of the markings does indicate if the motor is a high-, medium-, or low-power motor, but the numbers and letters in the markings are not linked to the gear ratio. You might be able to differentiate between motors with different gearboxes by comparing their speeds. One way to do this is by powering each motor at a low voltage (2V would probably work) and counting the number of ticks the flat side of the output shaft makes against something like a table edge over a period of a minute. You could then multiply that number by 3 to get the RPM at 6V.


Thanks Derrill,

What are the color codes for High, Medium and Low power - I have motors of each type. I have the 42mm wheel encoders so I guess I could use those to follow your suggestion regarding measuring the gear ratios.


Hi, Chris.

Red ink indicates a high power motor, blue indicates a medium power, and black indicates a low power.

I hope this helps you out!


Thanks Derrill!