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BrianG · 08:30 PM

Brushed ESCs don't get any motor feedback to know where the rotor is; they just "blindly" apply power to the motor and the motor takes care of commutation.

Sensorless brushless systems have to spin at a certain RPM so that the unused coil can generate a high and consistent enough back-EMF signal so the ESC knows which coil to fire. Depending on gearing and ESC settings, this can result in a rather abrupt start. You can minimize this by lowering the neutral deadband (in the ESC), gearing down, etc. Be aware that lowering the neutral deadband too much can cause the ESC to try to move forward or back a tiny bit if the throttle pot is not perfectly centered on neutral every time.

Sensored brushless systems are about as close to the smoothness of a brushed system as you are going to get because they use extra sensors on the motor to tell the ESC which coil to fire.

	(#2)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	04.12.2010, 08:27 PM Brushed ESCs don't get any motor feedback to know where the rotor is; they just "blindly" apply power to the motor and the motor takes care of commutation. Sensorless brushless systems have to spin at a certain RPM so that the unused coil can generate a high and consistent enough back-EMF signal so the ESC knows which coil to fire. Depending on gearing and ESC settings, this can result in a rather abrupt start. You can minimize this by lowering the neutral deadband (in the ESC), gearing down, etc. Be aware that lowering the neutral deadband too much can cause the ESC to try to move forward or back a tiny bit if the throttle pot is not perfectly centered on neutral every time. Sensored brushless systems are about as close to the smoothness of a brushed system as you are going to get because they use extra sensors on the motor to tell the ESC which coil to fire. Last edited by BrianG; 04.12.2010 at 08:30 PM.