Unfortunately I didn’t take many pictures during this build as it all happened in about a day.
After Rebound’s 2nd place finish at Motorama, I identified 2 key areas where I needed improvement, and one area which I thought would help.
First drive motor mounting: Previously the drive motors (brushless outrunners) were face mounted by their stator to the gearbox by M3 screws. Unfortunately these threads tore out under intense inertial forces when the robot was fighting which resulted in hot glue as a placeholder at the competition.
The new version is still facemounted (want to keep weight minimal and rear bearing support is kinda heavy) but now with M4s. Whoop whoop.
The other change is a new bearing setup. The bearings are now all contained in a single aluminum pulley/hub which presses into the blade. See 30lb Rebound’s build log for a pic of the new setup. The shaft was also upgraded to hollow 3/4″ case hardened shaft which is much stronger for the same weight as my previous solid 1/2″ shaft.
Lastly, the wedge was upgraded to have an entirely smooth frontward facing surface, relying more on welds. The downside is serviceability has decreased a little (it’s hard to get to the wedge mounting bolts, but I think it’s worth it.
I’m super happy with how this guy turned out and there’s nothing I want to change about it so on to the next bot!