Quote:
Originally Posted by Gary Dillard
Good calcs. I assume when you measure the drag coefficient with the motor "disconnected" you mean mechanically and not just electrically, otherwise the significant gearbox drag is in the equation. Did you measure the static friction coeffient between the pole and the wheels? 1.2 seems awfully high with that slick pole, regardless of what you do to the wheels.
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Yes, mechanically disconnected. (updated
post to reflect this)
The static friction coefficient was not measured. I just picked a value one can strive toward. You have to use what your design dictates.... maybe more in the neighborhood of .8 if nothing special is done to increase it. So you might need more normal force than I showed.
I ran the acceleration test to really determine the magnetic drag. I suspected that it was limiting the magnetic minibots and putting them at a disadvantage. I was unable to detect any significant acceleration that was a function of speed, but the data set was fairly noisy. It would be interesting to see what the distribution of speeds are for the magnetic minibots vs the clamp on's.