Quote:
Originally Posted by phargo#1018
...4 CIMs, 6 inch wheels, and a 12.75:1 toughbox...the motor appears as ~2.2 kg mass...
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I get the same numbers, using both m = J*(g/r)
2 and m = J*(ω/V)
2
The second equation clearly shows the inverse square relationship between equivalent mass and the vehicle speed at motor free speed (due to the combined effect of gear ratio and wheel diameter). Reducing the vehicle free speed from 10.9 to 5 fps changes the equivalent mass from 2.2 kg to 10.3 kg. For a 4 CIM drive that would be about 91 pounds!
These numbers are surprisingly large. But you appear to have taken great pains to conduct the test very carefully. Has anyone else done rotor inertia testing?