pic: drivetrain idea (comments please)

[EricH]

Originally Posted by bmarick

but if you do drop it, i feel, that it allows for the rocking motion of your robot to be a deteriater of how well your robot will trurn when you need it. Also with a droped wheel you must make sure your whieght is truly centered or you completly loose advatage of that extra two wheels up front.

Not necessarily. Look at 254, 968, 330, 60, 294 and a host of other teams that use 6WD "drop" style. They don't rock much, do they? If anything, the rock helps them.

Yes, you can put your weight dead center. But if you do, you lose most of 4 wheels, not 2. If you are balanced, only the center two are touching (if your drop is too large and you have perfect balance). When you move forward or backward, you get two more wheels. But as soon as you go the other way, you lose those two and get the other two. You keep doing this all match.

On the other hand, let's say you put your CG aft (or forward) of the center. You have four wheels in contact with the carpet and providing most of the power. You have two more that are not giving as much, but they are still contirbuting. When you rock the other way, you immediately rock back. This helps keep the robot upright (between the teams I named, I don't think more than one or two have stayed on flat the ground for more than a few seconds in years, and that was on going over sideways), as well as providing a baseline for the drivers on performance.


Oh yeah, and the rocking motion deteriorating the turn? Not hardly. The shorter wheelbase helps the turn, and with the CG at one end, you won't notice. With the CG in the middle, then you get some "fun" as first one end is on, then the other--faster turn in the middle, followed by a sudden slowdown as the end hits, repeat as necessary. Not good for fatigue in the parts.