Feigao motor help!!!
 

I want to get one of the feigao XL series of motors. I don't know which one to get because I don't know what all of the numbers mean like 8XL 2,084 RPM / Volt (4). The motors go from 6XL-14XL, so what do all of the numbers mean?

The rpm per volt helps to show power. Lets say for example your motor is making 2,000 rpm per volt and your battery is putting out 8 volts then your RPMs would be 16,000. As for the XL numbers that has to do with the size of the motor.

The S, L or XL is basically the length of the rotor - S- short, L - long and XL - extra long. The longer the rotor, the more torque the motor produces, but its also somewhat lower rpm cause the longer rotor weighs more. The number is the equivalent number of turns of the motor. The lower the number of turns, the higher the KV and the higher the amp draw. For the 8XL, its 2084kv and rated for max amps of 83. The 9XL is 1853kv and has a max amps of 74amps, 7XL has kv of 2382 and max amps of 95amps. They will not actually draw those kinds of amps, but the lower turn will draw more than higher turns.

There is also a practical issue - a 6 or 7XL looks terrific on paper, but in reality, they run real hot. Feigaos are inefficient to begin with and tend to run hot. I run an 8XL and it took RCM heatsink and fan to keep it cool even with reasonable gearing. I have switched to a TechnoNeu 1515 motor and temp probs went away and have been able to gear up and still run cool.

Last, the Feigaos have a weak front end bell/can joint, they pop off easily. I wouldn't run a Feigao/Wanderer/Nemesis without an RCM heatsink. That heatsink basically captures the motor in a bracket and eliminates the front bell from separating from the can plus helps keep it cool.