pic: Unique drive concept

[Sean Schuff]

Originally Posted by Jonathan Norris

My main concern with this idea is the torque required to move the center 'module', because most of your contact with the ground will come from those two middle wheels... and if they provide too much friction you may just end up turning the whole body of the robot. So instead of having a crab drive you have your robots body turreted.... with your center two wheels staying put...

To solve this you would have to either program the wheels to turn the direction your are trying to move the middle module, basically running the wheels in opposite directions helping the big CIM turn your center module. Or you may want to use omni wheels over the kit wheels...

Something about this design puzzled me until the aforementioned post appeared. The middle wheel module would have to be fairly free of friction relative to the frame in order to turn within the frame. This would allow the center drive module to turn in nearly any direction and provide movement in that direction. Great concept! However, what if you want the whole robot to turn? You would need to create friction between the the center drive module and the rest of the frame. I'm assuming that comes from holding the drive module in place relative to the frame and running the drive wheels in opposite directions. Is my assumption correct?

To echo what Sean said about high-siding the drive wheels - make sure the challenge does not require ramp-climbing of ANY kind. Even the shallowest of inclines will render your robot immobile. We experienced this challenge during this year's competition. I beg all teams to consider how to be most accomodating and complementary when designing a robot that interacts with another robot on your alliance - i.e. climbing ramps to score 15 or 30 points.

Another factor to consider with this design is when your robot gets into pushing matches - if your robot is lifted up even slightly on one end you will be at the mercy of your opponent.

I really like the idea - with some tweaking I think it could be a great design!

Sean