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Unread 24-12-2012, 01:40
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Tom Line Tom Line is offline
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FRC #1718 (The Fighting Pi)
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Re: Ideal robot speed

Quote:
Originally Posted by Levansic View Post
Tom,

What size wheels are your numbers from, and what speed are you using for the CIMs?

My calcs, using the free speed of CIMs, suggest that you are using 3.3" wheels, which doesn't feel right. I have never seen anything close to the published free speed of the CIM motors, when attached to unloaded gearboxes. Too much friction.
4 inch wheels. Stage 1 reduction 12:50, stage 2 reduction 10:XXXX, where XXXX is varied to obtain the final max FPS.

You cannot use the free-speed of the cims. My calculations include drivetrain efficiency and a speed-loss constant that is empirically determined. Grab JVN's design calculators. I've been puttering around combining the old motor-specs excel sheet with JVN's calculator so that acceleration, distance and time can be easily calculated for drive trains, arms, etc.

Last edited by Tom Line : 24-12-2012 at 01:44.