pic: 'I' drivetrain concept

[GeeTwo]

Originally Posted by RyanCahoon

Have you considered the loss of traction you're going to get by only driving one of the wheels in the primary drive orientation? At best, the robot's weight will be distributed between the single primary wheel (whether omni or plaction) and two of the side omni wheels. This will reduce the amount of force you can apply before the wheels start slipping, meaning you won't accelerate (or push, if that was a consideration) as well as a drive system where all wheels are driven

Originally Posted by BotDesigner

I am not sure if what I am thinking is a very good approach but it would seem that by using a high-speed/low-torque gear ratio we would be able to somewhat get around this issue. The high speed would allow us to move quickly even though a percentage of our speed would be lost to slippage while at the same time our reduced traction would allow us to use less torque without a stall. How does the gear ratio of approximately 4:1 for the plaction wheel and 2.81:1 for the omni wheel sound using for using with 3 CIMs? If these are ridiculously low (I am pretty sure they are) we could do something more on the level of 5.95:1 for the plaction and 4:1 for the Omni.

Even if you had 6 CIMs geared down 50:1, you still couldn't generate more pushing force than the strafe wheel's coefficient of friction times the weight loaded on that wheel. It's pretty hard to see how you could get much more than half the weight on that wheel under good conditions, and you'd probably be limited to a third or less if you got into a pushing match. You would never be able to keep up with a decently designed robot with four or six of those same wheels (which collectively bear all of the robot weight) all pointing the same direction. Also, because you only have one traction wheel, there are minimal forces available to keep you from being spun by an opponent.