Find rotation axis, tracked Vive controller

Hello!

I’m developing a wheelchair simulator for Virtual Reality.

I was using vive tracking pucks placed in the center of the wheels to get their rotation in the engine. (example video: YouTube)

Now I want to use the tracking pucks to track the person’s wrists and I have placed a Vive controller on the wheel. The problem is that it doesn’t rotate around the wheel axis like the puck did.
Does anybody know a way to ‘calibrate’ or transform the controller rotation so I can get the correct axis rotation data?
This is what the motion looks like right now: - YouTube

It should rotate vertically, or maybe better calibrated so it would work on wheelchairs with wheels at an angle.

Thanks!