I'd be more than happy to answer some more questions. It's not quite the largest chassis size. It's a 25x25, though we are exactly 18" high!
Motor count is at 8 right now.
- 4 for the drive
- 2 for the elevator
- 1 each for the intake rollers (the kids found it was easier to position the stored balls with seperately powered rollers)
For the ball pickup, we use a couple different devices. The outboard intake roller is a single tank tread pulley with the tank tread wrapped around it. This wheel is mounted on a rear-mounted swing arm, and can move up and down to adjust to varying sized balls (or the stitching on the ball.) We use chain and sprockets to run this roller off the 1st impeller motor. It's sped up, but not by much.
We then used the rubber 2.75" wheels, but turned the tread around so that we could, again, adjust for varying size balls. The curved walls that we walk the balls up are mounted at the top of their arc, and float on the bottom. We use the vex-legal elastic bands to pull the bottom of the arc, which keeps tension on the ball as it's walked up the arc. We've seen systems similar to this on FRC robots, but obviously nothing on a FVC bot.
Our Auto-mode is still being tweaked, as we weren't totally happy with it. Yes, you can only start with two balls, which we load in our hopper. We elevate the hopper and dump the balls in about 2 seconds. We then lower the hopper, drive forward and pick up one more ball from the pile in front of us. While the balls works its way up the intake wheels, we back up to the goal. Once the ball is in the hopper, we elevate and dump the 3rd ball. At the moment, it's all done by timing loops, which we had to tweak over and over to get it right. For our next comp, we'll probably have encoders and bit more tweaking done.
However, the three balls in Auto wasn't even close to what Team 40 was putting up. I'll let them post their auto-mode (and robot description) if they'd like. They're the main reason we want to improve our auto-mode.
I'm waiting for the pictures too! Keep an eye out on the Connvex.org website as well. There should be some pics there soon. Hope this helps,
BEN