2 pole vs 4pole motor torque?.. - RC-Monster Forums

RC toy · **2 pole vs 4pole motor torque?.. -** 09.14.2012, 01:27 PM

Hello my fellow physicists

Recently, I found some info about how poles affect torque/RPM. As you probably know, that is 4 pole motor will have twice the torque and twice less RPM as a 2 pole would have.
Also that 4 poles make about 3ft/lb while their high reving brothers make 1.5ft/lb of torque per horsepower (I think he was talking about AC motors)

Then i remember an old thread: http://www.rc-monster.com/forum/showthread.php?t=28030

This message to be exact.

Quote:

Originally Posted by nuz69

Quote:

Originally Posted by RC toy

ERBE with 1515 2200 kv and 18.84259 : 1 total gear reduction(65t spur , 18t pinion) on 6s reaches 50 mph
If I go to 1518 1800kv then to have the same top speed I need to change spur to 54t. In chase of that I get 15.65385 : 1 total gear reduction and that's a way lower.

I can't believe that with gear reduction that low I will get beter runing times

Have faith ;)
The amp your motor will eat does not depend only on the gear reduction, the 1518 will produce more torque for the same amp rating, that's why it will consumme the same current for the same top speed than the 1515.
More over, the 1518 will have a better efficiency because it will handle the same power in a bigger size and at a lower RPM, so longer runtimes and lower temps ;) I warranty you the result ;)

Now if the mentioned 1515 and 1520 consume the same amount of amps, how does one make more torque than the other? I do realize it has a longer rotor, but the two different statements contradict each other. Im confused.

Please explain. Or is it a different story with AC motors? (like they have size standards or something?)