Good find, Jim! And, thank you for starting this thread.
I must say that a couple of things inspired this design. One was this thread, and another was the failure of my home's garage door opener this past spring. After replacing the gears in my own garage door open twice, I figured that these gears may be good to try on a FIRST robot.
Also, I recall that there was an FRC team in St. Louis who used these same gears in their drive train this year. I forget who it was.
We did some testing on these gearboxes, and found that it takes about 85-90 ft-lbs of torque to strip the plastic teeth. We actually broke the large gear hub with a previous design at 60 ft-lbs, but then we beefed up the support around the hub so that the weak link in the design was indeed the gear teeth.
We have found a few things about this design that we like:
1. It is lightweight. The entire gearbox weighs 1.1 pounds.
2. The gearbox is quiet.
3. The CIM motors are out of the way, leaving the center of the robot with plenty of room for game object pickup (if needed)
Here is a video of a 4wd mecanum system using these gearboxes.
Sincerely,
Andy B.