i would like to move the pointers on the measuring device so that they go back and forth. Due to the inclination of the main object, however, I cannot simply change the rotation of the Z-axis, because the pointer then moves incorrectly, since the main point is aligned to a straight horizontal line. Can I rotate the object in edit mode so that the slope is the "new standard"? Hope my englisch is not too bad.😅
If you rotate your indicator around Z axis first, and then rotate it by another axis, it works:
However, notice how rotating it around X axis doesn't just change X rotation in the Numbers panel - this is because Blender automatically calculates the rotations needed for your object to rotate along chosen axis as if it didn't have some rotations already (as if it had the rotations applied, "baked" into the mesh).
The logic behind that is simple: Rotating something around axis Z by a degrees and then around axis X by b degrees is not the same as rotating it around X by b and then around Z by a - it's like with division, it's not associative.
This is why you can precise the order of rotation - since I rotated the indicator around Z first, if I change the order to have Z before X, I will not get weird transformations in this case:
This is of course not a general solution, because sometimes there's a lot of transformations you want to make, e.g. if the indicator rotates around 2 axes and the meter or whatever the indicator is a part of, rotates around all 3 axes, this will not solve your problem. "Part of" is the key here, you should parent one object to the other if it's supposed to follow it, as in this answer by Moonbot: How do I rotate an object along it's own axis (windmill)
If the problem is not in animation or something else dynamic, but just in modelling, often you can just change the orientation from global to local or custom (the plus sign):