Solved Bi motors plane not going straight


New member
Hi everybody,

First of all, as this is my first post, let me quickly introduce myself. I'm Edouard, 30 years old guy from France (excuse my english ;)), I'm in the hobby for a year and a half flying mostly a FMS Kingfisher and a Hobbyking Bixler 2. I follow the Flite Test adventure since 2017 on Youtube, and this definitely brings me into the hooby !

Recently I've decided to build a FT Sea Duck from plans (self isolation gives times !), which is almost done.

I've configured differential thrust, which works well, rudder input make one motor or the other to spin.

But I actually have an issue to go straight, my left motor seems to push harder than the right one, so when I try simple taxi tests, the plane is spinning to the right when I use only the throttle input.
Maybe this can be related to ECS calibration (not sure of what I'm talking about) ? This is my first build, so I'm a perfect noob :cool: !

Here is a video of what is happening (I only use rudder input at the very end trying to going straight):

Also I forgot to mention that I'm using the FT Power Pack C Radial, so both motors and ESCs come from there.

I know the Flite Test community is great, so I though that this forum was definitely the right place to get help !

Thanks in advance for your advice.


Legendary member
its hard to tell in the video but it looks like you have both motors spinning in the same direction. they should be spinning opposite.


Legendary member
well then yeah you might want to try calibrating the esc. to do that turn your transmitter on, plug in the battery and let it connect, then with the transmitter still on, simply unplug the battery, move the throttle lever all the way up. then plug the battery back in, you will hear a series of beeps, when they stop move the lever back to off and you should hear one more beep.