So, here's my take on 8WD vs 6WD. Now, this is only coming from what I've read perviously and seen out of a 6WD, so take all this with a grain of salt. Maybe a teaspoon.
6WD
Wins:
Lighter and simpler than 8WD, obviously due to one less set of wheels.
Yeah, that's pretty much it.
8WD
Wins
-More maneuverable. With 6WD, the turning radius of your robot, I believe, becomes centered between the center wheels and whatever outer wheels the robot is sitting on. With 8WD, it's in the center of the robot.
-Able to overhang. On a 6WD, the robot is sitting on 4 wheels at a time. The center ones, and a set of outer ones. These outer wheels are set out at the far ends of the robot. When you start to try and overhang, as soon as one set of wheels comes off the surface you're on, the robot is going to start tipping that way. With 8WDs center wheels, the robot still rests on 4, but the weight distribution of the robot along those 4 wheels is more centralised. As long as those 4 wheels are still in contact with the surface, you shouldn't tip over. Weight distribution on both of these is a huge factor, so you saw some teams on 6WD and West Coast able to overhang, but I believe this rule generally holds true.
-With the raised wheel set and a sloped chassis, overcoming obstacles is much easier.
Anyone finds flaws in this, please tell me. Writing down wrong information then having CD correct me is usually how I learn here
