local rotation per axis between frames?

Hi all,

I'm trying to find the roll/yaw/pitch change in local space between each frames for my gameobject. So, its x/y/z change of orientation relative to the new frame (not the world rotation, but local difference). Note the object itself has no parent and if possible I'dd like to keep it like that.

Been trying to tackle this for some time, but I'm one of those with hard times with rotations and quaternions...

Thanks for your help