SPSF posted:Dumb question: Aren't brushless motors prone to cogging at low RPM?
Most brushless motors I've seen are on high RPM applications: RC vehicles and Airplanes, weed wackers etc. Except for a drill, but how long are you drilling something at a low speed compared to a train going around a layout at a low speed.
Historically, the major issue with synchronous or single phase asynchronous motors was that at 0 rpm they produced 0 torque. Thus, they were inherently not self-starting. Another motor was used to spin up the rotor and then disengage once the rotor was at speed. Asynchronous motors solved the problem by using 3-phase and such motors produce a tremendous amount of torque at 0 rmp as shown by the asynchronous motors used in a diesel electric locomotive. Synchronous motors with VFD the feeding frequency is so long that the motors can self start. For asynchronous motors, cogging has never really been an issue. For synchronous motors one can design the motor to have very strong cogging as in the case of a stepper motor or minimized cogging depending upon the application.
My weed wacker has VFD. I can control the speed of the rotor by how much I pull the trigger, and as it says it is all digital so it is going through a VFD seed controller.