[rockydongre]

Hello guys,
I am doing a project in which i have to track the trajectory of an airship with two propellers which can swivel around to provide thrust vectoring. the propellers are attached to the airship through a rod which rotates to provide the swiveling of propellers.
so i defined a sphere with airship in it,gave embedded rotation to the sphere and gave superposed rotation to the region containing the rod. Also i have defined a cylindrical region for rod for swiveling and inside that i have my propeller region. but what motion (or reference frame or coordinate system) should i give to the region containing the propeller so that it remains aligned with the rod and hence swivel.

please somebody help, i am stuck on this. its a matter of my carrier . also if you could not fully understand what i am saying but you think that you can help me, plz reply