About this 3D model
this is a half sphere with markings every 5 degrees and a cross hair on the front plane. The idea is to use it to measure angle misalignment of a solar panel relative to the sun. It has a range of -90 degrees and you can pretty easily read off with 2 degrees of resolution. It can be read from the front or that back, and has a 1/4-20 hole on the side to mount it. I printed it on the Ultimaker at normal resolution, with the opening facing down and no infill, and it turned out quite good.