How to Reduce / Negate Torque


I've been searching post on this topic and yet didn't found much.

I'm looking for a way to shut off the uncontrolable yaw on my planes.

I use wheels turning in opposite directions (coaxial stuff i think) and make sure the COM is in the exact middle, behind the wings (or in the exact middle in case of helicopters) and yet ALL my aircraft goes sideways, they turn eithe rleft or right, always.

is there a way to negate this ?

how can i attach my engines to have the drag the plane while not transfering torque to the structure ?

i read somewhere that swivel or hinges or unpowered wheels and yet the whole plane is affected by this unwanted torque.

ps : i'm no engineer and i'm not english native speaker. i might use terms improperly or have misunderstood some physics rules. in such case please tell me where i went wrong.
your on the right way, use a wheel spinning in the opposit direction and attach some braces to it to make it heavier. it should look somewhat like this...
Yaw? the torque only causing unwanted roll, not yaw.
If it is really yaw, the problem might lies to the propeller rotor design and/or vertical elevator.
i might have used the improped word (bear in mind that i'm french :) )

what i mean is the plane will go left or right. it won't roll, it just goes left or right, depending of how the wheel turn.

either they go both toward the outside or the inside, the plane won't go straitght forward.

it doesn't seem to be a COM issue and trying to add weight on a side will make it roll but won't fixed the tendency to not goes straigth forward.

i THINK it's caused by torque.

ps : your video on planes are awesome. i can FLY solely because of those video... :)

pps : my pc died friday so i don't have my saves. i'm making a plane now, i'll upload it later so you can see what i talk about