OK i cannot get these imgur images to post but to your post wlutke, in order to have any movement on the protractor dont you have to remove the long part of the protractor so that it isnt going inside the tonearm any longer? I cant see how the protractor would rotate if you dont do that.
https://imgur.com/a/ixbHTQO
See if you can see those images.
https://imgur.com/a/ixbHTQO
See if you can see those images.