Parametric solar filter for a telescope

thingiverse

**Do not use this design to look at the Sun directly!!** This filter is not securely attached to the telescope, and if it comes off accidentally, you can instantly go blind - if you are looking through the telescope at that moment. Instead, use this only for camera/webcam astro-photography of the Sun. Fully parametric design for a solar filter for a telescope, based on a black polymer Solar film from Thousand Oaks manufacturer. One can buy square pieces of the film online quite cheaply. I paid $22 CAD for a <a href= https://www.amazon.ca/Solar-Filter-Telescopes-Binoculars-Cameras/dp/B01770FDAC/ref=sr_1_22?dchild=1&keywords=binoculars&qid=1613483898&refinements=p_85%3A5690392011%2Cp_36%3A-10000&rnid=12035759011&rps=1&s=electronics&sr=1-22>6x6" filter from amazon</a>. The filter is a bit small for my telescope (Celestron C6-N; aperture 150mm), which is not a big deal - I only have to sacrifice the aperture slightly (down to 144mm), but I save a lot of money compared to the next (larger) filter size. I designed this for my Celestron C6-N telescope, but the design (Fusion 360) is fully parametric, so in principle can be easily adjusted to a different scope, and a different filter size. The interlocking part was copied from the telescope's cover lid - it is easy to use, the filter stays on reasonably well (doesn't come off by itself), but still not reliable enough to make it safe for eye observations of the Sun - only for astrophotography. It consists of two parts. The top part has a small depression for the filter. I cut the corners of the square filter, and glued with a Cement glue it to the top part (the silver side has to face the Sun!), then attached it to the bottom part with eight M3x6mm bolts and matching M3 nuts.