This is totaly a shot in the dark, I wouldn't upload this untested stuff if I had found a filter I liked and/or the next eclipse would not be in three days. My Telescope will arrive these days and then I will measure the actual tube diameter and parametrize and print this out for the very first time, so you are very likely to experience Problems with the two rings snapping together. Please don't waste your costly solar filter foil until you have checked and evaluated this for yourself! Update: YEAH!!! Worked on the spot. The two rings need quite a bit of force to click together. You also need force and thin tweezers to get them apart. Maybe it's a good way to test if they slide with very small play when the inner ring is inserted the wrong way, then cut out the solar foil, then click together. Test if the rings hold the foil safely by gently blowing against it. FYIO: The Filter in the SCAD File is for a TS-Optics Starscope 609. Have Fun! Beware: If you do stupid things with this, it might cost you your eye vision! It's a good Idea to put your hand in front of the ocular and test for a bright lightbeam before looking into it.Use the inner ring to draw a circle on paper. make a Sandwich: "Small piece of Paper with circle, little bit bigger sheet of filter foil, little bit bigger paper". Tape together with lots of scotch tape around all borders. Cut out with scissors. Put foil in outer ring. Blow air until foil lies flat. Press down inner Ring to lock filter foil.