Quote:
Originally Posted by bs7280
Please keep into consideration that our season is over (we had a good run, first time getting picked) and we are currently working on a new frame from scratch (preserving this years bot) in order to test drive trains. We also have a good amount of money left in this years budget that we can most likely buy the gear boxes (we already had the wheels) especially considering that they are reusable.
This years drivetrain was a 6 wheel tank drive on the andy park standard KOP frame using the long formation with omni wheels in the front and back of the bot, and kit standard wheels from andymark (highgrip) in the middle, all 6 inch. we had 4 cim motors on two cimple boxes. We added the omni wheels because it could not turn for its life on carpet. It worked well in competition, as it could run very well when it was just going back and forth collecting and shooting frisbees. I was pleased with it because last year we were basically a sitting duck with our 6 highgrip wheels powered by 2 cims.
The problems came up when we had two line up our bot to shoot/load frisbees. Unfortunately our bot could not change the firing angle at all, and had no sensor, so the shooting had to be lined up by shooting very specifically at the bottom of the pyramid. It worked great in auto mode, but telop was tricky because with tank drive it was impossible to make slight adjustments to alignment. Especially with lateral movement.
The feeding was the same thing, but easier because we could communicate, still took way too long. I will admit our feeder could have been much better designed. On the optimistic side, lining up on the pyramid was easy and took no moving parts at all for climbing.
I don't have any great videos, but we have some O.K. ones on our website with more elsewhere that need to be uploaded. there really are not any obvious problems at first glance, but it is defiantly not fast, and it does not block/handle blocking well. |
Rather than looking at a new drivetrain, let's analyze what was going on with your setup. You said the standard kitbot drivetrain was not turning on carpet. Where was your center of gravity in this setup, and are you sure you dropped the center wheels in the 6 wheel drive by 1/8"? Make sure your center of mass is low and over the center two wheels. If this still does not remedy your issues, look into going to Toughbox gearboxes, or something with a higher ratio. I think the CIMple boxes house a 4.3:1. This ratio is meant to give you a lot of speed, but not much torque. You might need to drop down to 8 or 9:1 in your gearboxes. The toughboxes should be enough, even with high traction wheels, to allow your robot to turn smoothly, given that the center wheels are dropped 1/8" and the center of mass is low and over the center wheels. This is in fact what the kitbot on steroids project by Team 1114 is based on.
Alignment issues are a pure driver practice thing. It's much easier to get your driver to practice lining up in one sweet spot (and with the goal this year being so wide, you don't need to exactly have only one sweet spot) than it is to invest time and resources into an omnidirectional drive, only to use it just to strafe a couple of inches every match. Try expanding your feeding are on the robot. My team's loading mechanism on the robot is the length of 2 frisbees. We had very rare issues with lining up to the feeder slot, and we ran a standard 4 wheel wide drivebase.