[FTC]: DC Motor Speed

[Rick TYler]

Originally Posted by John_1102

In order to acheive max speed use large to small gear ratio because direct connecting the battery to the motor will give you the max speed of the motor.

If I remember correctly, last year the TETRIX folk warned against gearing up drivetrains using the 12-volt motors after a series of gearhead failures. They recommended either direct-driving or gearing down the motors. This was a recommendation for drivetrains, so I'm not sure if they make similar suggestions for other applications. We broke three gearheads last year on a geared-up drivetrain and the problems went away when we changed to a slower design.

I know a lot of teams are planning on heavily gearing up wheels to shoot balls this year (including our own FTC team) and I expect it to work pretty well since the intertia of a whiffle ball is a lot lower than that of an entire robot. Just in case, we have a stock of spare 12-volt motors and a design that lends itself to rapid swaps.

[JohnFogarty]

I do remember that, we blew 2-3 motors ourselves even one at nationals. It really depends on what you need the motor to do. Like if all you want to speed up is a wheel then it shouldn't be too much of a problem.

[Richard Wallace]

Originally Posted by John_1102

I do remember that, we blew 2-3 motors ourselves even one at nationals. It really depends on what you need the motor to do. Like if all you want to speed up is a wheel then it shouldn't be too much of a problem.

Whether it is a problem will depend on the size of the wheel and the function it performs. A large traction load on a big wheel could easily overheat a geared-up motor. That is why it is much more common practice to gear down.

[JohnFogarty]

The thing i find funny is at the end of last year we took apart one of our broken motors and they are geared down to the slowest speed possible.