I'm trying to get 30FPS even

Indeed you must have a fixed timestep if you're doing any integration. I've always used render tweening for that. If you were using anything other than B3D, it might be a bit messy, because you have to SLERP quaternion orientations and animation can be a real pain, but B3D makes tweening easy.

See here for the theory :

http://www.gaffer.org/game-physics/fix-your-timestep/

And here for the B3D Practice :

http://www.blitzbasic.com/codearcs/codearcs.php?code=1497