Rotational axis for hydrodynamic screw
 

I've been working on a hydrodynamic screw simulation and I'm having trouble fixing the axis of rotation. I've been able to limit the translation in the motion controls, but when the fluid strikes the screw and starts turning it also bounces it around rather often through other geometry even with the collision model on.

The screw has an angle of 30 degrees if that helps at all, motion is coupled, translation allowance is set to 0 in all directions.

If anyone could shed any light on how to fix the rotational axis, I'd greatly appreciate it.