engine cuttoff
 

hi every one i just put a new brushless motor in my cub and when i move to full throttle sometimes the engine just cuts off. i dont remember what this means but can anyone tell me how to fix it or tell me the problem. thanks


peace

RE: engine cuttoff
 

Your motor is probably trying to draw more current than your speed contoller is rated for; causing the speed controller to shut down the current. The easiese fix is to install a larger rated speed controller and see if it corects the problem. Alternatively, you can install a prop that will require less power, thus allowing the motor to operate within the rating of your current ESC.

I had a similar problem with one of my planes. It is the Rare Bear from ThunderTiger. I installed a TowerPro outrunner, using a 15amp ESC, and tried to fly it with the stock 3-blade prop. At 75% throttle the motor would cut out, but if I kept the throttle below 75%, the plane flew fine. I replaced the 3-blade prop with a 2-blade, keeping everything else the same, and now full throttle is no problem.

RE: engine cuttoff
 

thnkas i probably will fly this weekend with not going full throttle and then get a higher amp rated esc and put my lower one in a plane that needs it

RE: engine cuttoff
 

Another issue could be your battery. Some users don't realize that if the "C" rating does not support the current draw then the battery voltage tends to drop. Once it reaches the "drop-off" the ESC will stop the engine. Changing the ESC from say a 25 amp to a 40 amp will not cure the problem. But, saygoing from a 15C to a 20 C with the same voltage and "mah" will most likely cure the problem.

RE: engine cuttoff
 

The battery is the more likely cause, in my opinion. The voltage produced by the battery will always drop under load. If it drops below the low voltage cutoff (LVC) setting of the ESC, the ESC will cut power to the motor. It is designed to do this in order to protect the battery from being over-discharged.

There is no need to guess about this. Get a wattmeter and look at voltage and current while running the motor. You'll instantly know whether the battery voltage is sagging below the LVC OR whether the current is too high for the ESC.

- Jeff