Low Cost Planetary Gearbox Source...

[Richard Wallace]

Originally Posted by Joe Johnson

Wow, lots of good data, thanks.

As to the conclusions, I am not sure I entirely concur. In particular, much of what you recommend involves the particular motor the gearbox comes shipped with (which is not a legal FIRST motor).

...

My final comment is that the data generally support that these gearboxes are not jewelry. They are cheap and dirty. But... ...I would just say that the price and effort are right... ...for the right application.

Joe J.

As Joe correctly points out the conclusions I offered above are based on the motor that came mounted on the gearbox; i.e., on the assumption that the standard motor performs as advertised. My non-linear torque vs. speed results strongly suggest that the motor heated up during testing (as does the smoke observed when load was increased to 20 Ampere). So the gearbox may in fact be more efficient than I concluded, if the motor was operating less efficiently because it was running hot.

In any case, I still would not recommend this gearbox for continuous running above 10 Ampere load. And I still think the noise it makes is annoying.

My team plans to try launching balls using two of these gearboxes, fitted with kit FP motors and 6" wheels. For that kind of loading I would expect them to last through a FIRST season.