ALPHA wrote:tomhugill wrote:
I'm confused. What do you mean by speed controller? Every electric motor is controlled by a speed controller. A speed controller can't give your motor more torque. A better quality one can give better throttle response.
Speed Controller
....several different types for different apps ...I've seen some that look like volume controls...so you can actually dial in the resistance...any change in resistance cuts or increases current flow..so does affect the power output of any motor Ht or Hs
I also don't understand how you can argue the motors not a factor when specific crawler motors have 1/3 rpm of a standard 540.
The lower KV (ie torquier) motors I've had always seem to have stronger magnets and therefore are harder to spin by hand.
I'm not arguing anything about the motors...just defining HIGH torque vs High speed ...and how there is a myth about performance that exists
ALPHA
First off you can't increase flow of current, only decrease it. This will make a motor run slower at given throttle but won't increase torque (try it in your tank by wiring a resistor in series with the motor). Going back to v=ir for constant voltage increasing resistance decreases current.
Anyway back in the days of mechanical speed controllers that's how you varied speed, increase resistance and as I'm sure you know run at low throttle those things got aweful hot, I know people who had boats set fire using them.
The way an esc works now is by sending a series of pulses to the motor by varying frequency changes speed. Voltage remains the same.
Typically a motor will draw much more current when stalled than when running. This is because when running, it is also acting as a generator, creating an EMF which opposes the applied EMF and reduces the overall current. As more mechanical load is applied, the motor slows, the back emf decreases, and more current is drawn. If sufficient mechanical load is applied, the motor stalls/stops rotating, and therefore there is no back EMF at all, and the current is limited by the supply or by the resistance of the windings.