[RyanCahoon]

Not at all arguing the physics of friction, but one thing that may change with the extra wheels is how the robot performs while turning. While with this robot, you will certainly not get any more friction when driving in a straight line, distributing the frictional force of the wheels around the robot means that when turning, the amount of torque that each wheel is supplying will be different as its distance to the axis of rotation, for both the linear and transverse friction of the wheels.

While I have not done any actual math, playing with vector diagrams a little yields this:


So it seems that not only are more wheels hurting your weight, they're actually decreasing your ability to turn.

Originally Posted by samboydh

all the wheels are powered. That clip dosnt do justice to how well it preforms.

Interesting; have your tried to do comparative testing with only four wheels? Or someone correct me if I'm wrong.

--Ryan