Get Rotation on Axis this Frame

Hi there,

I need to know, how much an Actor rotated this frame around a specific axis.
Basicly I have a key which is rotatable in any direction and I need to know, how much he turned along his forward axis so that I can trigger events when he is turned quickly like you would do to unlock a door.

Thank you in advance,

Like this? Maybe you have to adjust the subtraction.

Hmmm… I replaced the subtraction with a dot product to convert the distance to an actual angle. It almost works. Right now it’s tracking two axis though, but I need only one.^^ (When I connect the z node, it tracks exactly the two axes I don’t want to track)

Here my nodes:

This was a hard one. I found a solution which seams to work in every direction.