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Re: Motors Vs Motors
Which motor to use really depends on a couple factors:
Weight - Obviously if you want a lightweight arm you don't drive your manipulator with a CIM.
Torque/Speed requirements - This is dependent on the application, obviously for a shooter you want a a decent mix of both torque (to get up to speed quickly) and speed. Obviously, this is a tradeoff unless you can put two motors to the application but this increases weight.
Size - Obviously if I have only a 4 x 1 x 1 space to put a motor and transmission into I am NOT going to use a CIM motor.
Thermal Mass - For the most part this is not an issue in FIRST but occasionally it causes a team a problem. Running a motor near stall generates a lot of heat in the motor (running any motor generates heat) You have to take this into consideration. A motor getting two hot can cause problems, you could demagnetize the magnets inside it, you can melt the internal components. Or it can become a safety hazard to anyone working on your robot, someone smarter than I can tell you numbers but motors can quickly become too hot to touch. This is one of the reasons CIM motors are often used in the drive train, the larger mass of the motors allows them to handle more heat.
Electrical requirements - Along the same lines as Thermal Mass, most teams dont take this into consideration. If you have 4 Cim motors, and 2 FP in your drive train and you get into a pushing match you will be running those motors near their stall points, this will suck your battery dry. What this means is that when you try to turn, or raise an arm, your motors will not be able to draw nearly as much current to do so. Keep this in mind.
My suggestion on what to use motors for? Look to the past, check out the successful teams and how they did what they did. The motors may not be the same but chances are you could look up data for those motors and see if you have a motor with similar characteristics. There is NO reason to reinvent the wheel.
Just my $.02 (not adjusted for inflation) Sorry for the book but I hope it helped.
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