I made a Chinook style twin rotor helo,
you absolutely need something to counter torque so remember to set one rotor to rotate in the opposite direction
I also included a control unit with SAS and a reaction wheel to aid with stability and steering
Hinges under the motors act as the collective bound in my case to the pitch controls
Motor RPM bound to Axis Group 1 which is bound to the same keys as throttle up and down
Main issue with this version is I get a right hand turn/drift when pitching forwards
Used small / high rpm motors
https://kerbalx.com/headdie/Rotocopter-2