Not to hijack this thread, but...
Our team was planning on using
ball casters with CWD. We have a drive platform and its incredibly maneuverable.
3 years ago, we used omniwheels on a 4-wheeled robot for slippage, and it worked pretty well. However, it was a huge pain when they broke, considering how expensive they were.
Apparently, (before my time, and there's not a whole lot of recollection about them, which could be good or bad) about 5-6 years ago we used a similar design to now. It was claimed to have great maneuverability, but if you dropped the robot or anything, the casters could dent, which would prevent them from rolling correctly. However, they're cheap enough where you can easily have extras on hand.
This year, when we designed the robot, we chose ball casters based mostly on these experiences. We assume that omnis would not provide any significant prevention from being pushed and rotated around our center. We were also being cost-conscious, being a pretty low-budget team. Plastic omnis would have been about 4x as much as a heavy-duty ball casters, which are also readily available at a hardware store.
Since we're using direct drive, powering omnis wouldn't be worth the hassle, either.
Basically, I want to make sure that our decision was sound. Based on our pretty limited test, it seems to work pretty well, but that means nothing in FIRST
Has anyone had any trouble with ball casters?