| Completely agree with Rick. From the figure you get you want a speed controller with enough of a safety margin over your stall current to be reliable but not too much that it won't cut out in the event of an over current when you get stuck in the weeds.
I would suggest about 10-15% over the stall current then go to the next available readily made unit above. So if your stall current is 8 amps then allowing 10%, 8.8, will take you to a 10 amp speed controller.
__________________ 
“Dirty British coaster with a salt-caked smoke stack, Butting through the Channel in the mad March days" |