skillet92

I have built a GP ultimate biplane and installed a eflite 480 i had a lipo battery from an old electric helicopter. It came as combo. The battey is some knock off 1800 11.1v 10c lipo. My quesion is that when i hook it up to the plane the motor does not seem to want to spin properly and some times just beeps and cut off. It even trys to start backwards at times. Do i need to invest in a better battery and if so what rating.

jdetray

A couple of thoughts.

Does the motor run OK if you remove the prop? If so, you might be using too large a prop.

Also, depending on the prop, that battery might not be able to supply enough current to run your power system at full throttle, but it should be sufficient to start and run the motor at lower speeds. The E-flite 480 motors are rated for 20-25A, which is more than that battery can reliably provide.

- Jeff

skillet92

The prop is a 12x6 which is at the up end. But at lower speeds i would not think that would matter. But the motor not even turning baffles me. It will jump in a direction and then just stop and i have to pull the throttle on the transmitter all the way down and then move it forward again. And i still get the same thing. It is like a relay is breaking some where but there are none. Does it require that large a battery just to run it at all?

jdetray

Just try it once without the prop. Too large a prop can cause the symptoms you describe.

Other causes could be bad connectors or solder joints, a broken wire in the motor, a missing or misplaced motor magnet.

As for the battery, you'll probably need a larger one anyway (larger mAh or "C" rating, or both), so perhaps you should go ahead and get one.

- Jeff

mrasmm

that battery max can put out something like 14.4A which is way low for that motor. The other thing to think about is ESC don't run at 75% throttle 100% of the time, they run at 100% throttle 75% of the time. That's why you can't get a smaller battery and just run the motor at a lower speed.

The turn over in the motor is controlled by the 3rd wire, so if the motor cannot get going fast enough and the prop slows it down, then the 3rd wire stops sending signal as often because the motor is spinning slower, until it stops and sends no signal, so the ESC will never change polarity =) hence the stuck motor

sparky925

My Feedback: (1)

I believe that you may have a short in the motor..
put a prop on the motor and spin th motor over with no power on. Does the motor spin freely
If you have 2 phases shorted together you will get a little drag when you spin it over. This is not like bad berrings drag, its
the motor becomming a generator and trying to produce voltage.