Friction clutch

Hello

I hope someone help me on this becuase i have stack for weeks without solution.

In the speedbrake lever i have add a dc motor with gearbox inside.
The move with the dc motor is good.
But this motor is very strong and don`t allow me to move the lever by the hand.
I move the lever but it needs a lot of pressure from my hand (this is not good and not real)
I want to move the lever without preesure when the dc motor hasn`t power.)when is stationary).
Also i want to move the lever and forward and backward.

I have hear for something like friction clutch.
The few that i found they don`t explaine how these things works or they are work for this that i want to make.

Have someone experience with these things or exist any other solution.?

Best Regards
Lambis
Greece
http://www.projectmagenta.com/lambis777project/

Try this link, friction clutch is explained ( and it works, i try ! )

http://www.opencockpits.com/modules....=getit&lid=229