Congrats! This really looks nice for a first gearbox. I really like some of the placement and packaging you have. But there are a few issues that need addressing. Also, could you provide some more views or more pictures? There are a few details I can’t quite ascertain from the single view.
First, you have a snap ring between loads on your output shaft. This means you’ll have a pretty hefty stress concentration on that point on the output shaft, creating a possibility for failure. There are plenty of ways to constrain that shaft without putting a snap ring between loads.
Second, you’ll need to reconsider your gearing or motor choices. 775Pros are NOT drop in replacements for CIMs. Since you only have a single speed and it’s geared quite high, your robot will most likely not have enough torque to break traction. Also, you’ll almost certainly pop your breakers (40A and main breaker) within a second or two of stalling, not to mention the damage the stalling would do to your motors. If you want to keep your fast robot, you’ll either need to switch to CIMs and employ some voltage or current ramping to prevent brownouts, or you’ll need to go to 4 775Pro gearboxes with a high and low gear.
Third, I think you need to add back some support to your plates. I assume you’re using the three bolts that pass through both plates to secure the gearbox to the tubing, but you need to make sure you add those details. Also, the output bearing hole on the last plate probably needs some more reinforcing. It’s basically cantilevered out from the rest of the gearbox, and I feel like that introduces the possibility of that plate flexing a bit at that bearing hole and causing some serious binding.
All in all, still a great first gearbox. Good luck, and happy CADding!
