Frying ESC's and Motors on MultiWii Quad

[boyfly]

A buddy and I have put together our first quad. But before we can get it in the air we are frying ESC's and motors. So far we've burned up 3 ESC's and at least 1 motor. It's happening on the same channel coming from the MultiWii flight controller. The ESC starts smoking when we try to throttle it up with a load on it. We're looking for suggestions to trouble shoot.

Here's our build:
Hobbypower Sunnysky X2212-10 1250KV Brushless Motors
SimonK 30A ESCs
MultiWii 2.5 SE controller
Turnigy 9X
F450 frame
Lipo 3S and 4S (tried 4S first time, 3S second time)

Any suggestions for how to start troubleshooting this one?

Thanks.

 

[cranialrectosis]

I built one of these today to prevent exactly that.

Do you see any motor jitters when you add throttle? If so do NOT power through them. Stop and re-solder the connections between the ESCs and the motors.

Did you trim the motor leads? If so, is the wire coated with enamel? SunnySky motors leads are often coated with enamel that you must burn off before solder will make a good connection to the ESC. This enamel WILL cause jitters and WILL smoke your ESCs and motor if you fail to make a good connection between the ESC and motor.

There are several things that will cause this. The most common is a cold solder joint or a short.

 

[boyfly]

The motors and ESCs came with plugs already on them so we just plugged them in. Maybe we need to resolder those connections?

 

[cranialrectosis]

Possible but less likely.

Have you calibrated the ESCs so that all the motors start at the same time? You do this with the props OFF.

If you have, do any of the motors 'jitter' when you add a little throttle?

 

[Andrew]

Another thing to check is the length of the motor mount screws, if there a little bit too long they squash and short circuit the copper motor windings.