[EricH]

Originally Posted by David

1. "Rocker Style"
Pros:
Decent Turning (Acts Like 4wd)
Great Traction
Designed Into Kitbot Frame
Good for climbing
Cons:
As the name suggests, if you do not balance it properly, it will rock back and forth constantly.
(I believe Beach Bots 2007 bot are a good example of a well balanced one)

2005-2007 all used a similar drive system. Two pneumatic tires as the center wheels; a pair of kit wheels as the front, and either two more kit wheels (2005 and 2007) or another set of pneumatics (2006) in the back.

Actually, it's all about weight placement with the rockers, not the balance. For 2005, we had a lot of the weight even with or behind the center wheels and didn't have a lot of drop. 2006 had a pretty balanced load and you could tell as it rocked a little bit more. 2007 had almost all of the weight in the back. This reduced the rock. Also, because we had pneumatic tires in the middle (I'm not sure where we got them from, sorry), we were able to adjust the rock as desired. Less rock? No problem, just let air out. More rock? Pump them up. We did go through the tires, though. I think I counted three or four sets of center tires that were dead from two robots this year.

As clear a view as you can get of our 2007 drive, aboard the practice robot: http://www.chiefdelphi.com/media/photos/27675
And the 2006, pre-front wheel change: http://www.chiefdelphi.com/media/photos/23376
And both, for comparison (post-wheel change for 2006): http://www.chiefdelphi.com/media/photos/27581