Help! Plane veering left/right

[James bob]

So I've had this rc mini guinea pig for a while and decided to repair it, however after a lot of crashes (it flew fine before) I've noticed they all had something in common, as soon as the plane gains some sort of speed or gets off the ground it violently turns left snd crashes. At first I thought it was that the props were spinning the wrong way, and i fixed that (left motor spinning clockwise and right anti-clockwise from behind the engines, the props were orientated the right way too), but the same thing happened, then i thought it was because of the motors being uneven, and i fixed that, but it persisted, I then calibrated my ESCs and then i noticed something, after calibrating them both separately, one motor would always spin up first before the other one, even with change of the travel in each motor, the same thing would happen, even with the smallest amount of throttle possible. (Ive tried connecting them to a single channel but that changed nothing).And now im wondering does that have enough of an impact to cause such a drastic unevenness of thrust, or perhaps its the radios fault.

Im using a spektrum dx7s transmitter
A s603 dsmx receiver
And two 2200kv motors with their 30a ESCs

 

[mastermalpass]

Sounds like you have un-intended differential thrust - you need to calibrate your ESCs. To do this, simply power on the transmitter, raise the throttle to max then plug the battery into the plane. The motors should continuously beep. Bring the throttle down to 0, and they should each then give the 'arming confirmed' beep and now when you raise the throttle the two motors should work in unison with each other.

 

[Tench745]

You say you've calibrated the ESCs, so that's probably not the issue. I'd double check that your motors are the same kv. Then oil both motors to reduce any binding etc that might be in the motor. Then just use sub-trims to get the motors to start at the same time.
I can't promise it'll work, but it's a start.

 

[TheFlyingBrit]

That definately sounds like a differential thrust issue, have you tried swapping the connections over for the motors left to right see if the problem transfers. That might tell you if its motor or software related.

 

[PsyBorg]

Is the plane rolling over or flat spinning to the left? If it rolls over that sounds like too low speed and tip stalling. If it flat spins I would look to see that your motors are turning opposite directions so there is no torque steer issue and second that the differential settings are correct. Funny how that little - sign in the wrong place can make all kinds of mystical things happen.