Rotation problem with Action Constraint I would like to trigger an action that I created earlier on a bone (Drumhit on the upper arm bone of a drummer).
The action would be triggered by another bone of another armature (snare on Drumcontrol) that rotates on the x axis.
The problem is as soon as I set up the Action constraint it rotates the bone. The action still works but it starts in a totally wrong position.
Can anyone please help me with this?


Here is the blend file:
https://drive.google.com/open?id=1r0wBDRb70z24FBue6z9qw0epDHmXOihz
In the Dopesheet, you need to check the action you're using in this Action constraint for the UpperArm bone, it is called DrumHit.

As you can see its first rotation keyframe is NOT set to W/X/Y/Z values of 1/0/0/0, but 0.721/-0.654/etc, that's why as soon as you enable the constraint it jumps to this angle.

So what you need to do is to change this first frame rotation setting to 1/0/0/0.

Also I don't know why your Snare, which is supposed to be the controller bone (Target), had a driver, so I deleted it for my test, otherwise it couldn't move.

Now when you rotate it on the X axis, it works.