CIM Motor Simple Explanation

[StevenB]

Originally Posted by DonRotolo

The short answer is power. More watts to the wheels means better performance.

Quoted for truth.

To expound further, the claim that a 2-CIM system inherently will get pushed around is a generalization rather than a fact. You could gear any system down to the point that it could bulldoze anything else on the field, but you sacrifice speed. You could make it fast, but you sacrifice torque. Since you generally want your drivetrain to be "traction limited" (e.g, your wheels slip before your motors stall), then you have to use slicker wheels, and you get pushed around.

Put another way, pushing ability is not a function of the number of motors you have. It's a function of your robot mass, the friction of your wheels on the carpet, and the ability of your drivetrain to deliver torque to those wheels. Using four CIMs instead of two doubles your power, which means you accelerate more quickly and gives you twice the torque for a given speed. But it doesn't directly increase your pushing ability.

If you're not comfortable with the physics behind this, I suggest you look at JVN's work on CD-Media.