Direct Drive to Diff E Revo Build

[Mod Man]

Most outrunners are capable of around 20,000 RPM. That is true for most Orbit outrunners as well as AXIs. That is due to magnetic saturation. Beyond that heat tends to build up and efficiency goes way down.

Much depends on each individual motor, though.

EMF is "Electro-magnetic-fequency". Back EMF is the back pulse the motor creates as it rotates. A motor requires voltage to run, but it also creates voltage as it spins. This voltage is read by the ESC to give a rough calculation of the motor's RPM thus eliminating the need for position sensing. Software is EXTREMELY important in eliminating cogging as is high torque capability of the motor. High voltage normally reduces cogging as well.

Matt