[Johncvt]

We had the same issue in our first district tournament in Centerline. What we did to fix it was to take a few small set screws or pieces of steel rod, ground one side flat and then used that to fill the outer half of the slotted hole in the gearbox plate. Then, we also Loctited the CIM screws. We never had a problem after that in our next district, regional and worlds. And we played a lot of tough matches where the drivetrain did get worked over pretty well.

This is indeed a design flaw that needs to be fixed. We also made 3D printed pieces for the gearboxes to also give them so additional protection from being hit.