Hi Wahid - Sorry to read you are having control problems. Having never built a Gyrostick I cannot comment on its stabilty. But a thought - are your rotors freely able to flap? Could your hinges be too stiff? I use thin polypropylene (code 5 plastic sheet) on all my autogyros. All four are quite sensitive to roll control input but within the ability of an average flier to handle. Not a lot of tilt movement is required. Three of my planes have rudder control but I do not have to use it, in fact once airborne I often forget I have rudder control. They can however be turned with rudder only and no tilt, and any subsequent roll to one side is soon corrected with rotor tilt control. Incidently all four planes have no built in sideways tilt to the rotor shaft, it is vertical when viewed from front or rear and with TX stick in centre position. Maybe this won`t help!
Regards, Colin