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Old 17-01-2008
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frogger frogger is offline
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Quote:
Originally Posted by Cooper View Post
why?
I'm not sure of all the reasons why some classes went down to 5 cell nimhs but one reason is that it limits the speed of the cars to keep things safe.

With brushless motors the kv rating refers to 1000RPM/Volt so where you have a 6800kv motor powered by a 7.4v lipo battery it works out to be 6800x7.4v=50320rpm.

Novak motors:
3.5 - 10,300 RPM/volt
4.5 - 8,200 RPM/volt
5.5 - 6,800 RPM/volt
6.5 - 5,900 RPM/volt
7.5 - 5,400 RPM/volt


So if you want to limit speed (as in the case of some 5 cell classes then all you have to do is limit the kv motor they can use (the exact same way that some classes limit the turns on brushed motors) but still allow them to use 7.4v lipo's.
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