3D printed 150 mm f/8 Newtonian telescope

thingiverse

This is a work in progress, I'm uploading now just in case anyone else wants to make improvements or change the optical design. Based on experimental printed optics, you can modify the f ratio and tube length if you plan to use glass optics instead. I wanted to create a 3D printed telescope solely for experimentation's sake, including the optics themselves, but I need to try some things first. The main challenges are determining whether PLA (or something else) will hold its figure, and then figuring out how to coat it since I'm unsure if they'll survive a trip in a vacuum chamber. If you want a functioning telescope, I'd recommend using glass and making regular mirrors for it; such small mirrors can be secured with silicone adhesive. The optical design is 150 mm f/8, which makes the telescope easy to manufacture. All the parts fit on a standard-sized printer. The reason for f/8 is that the mirror doesn't need to be parabolized as a simple spherical figure will suffice. I'm also working on a simple miniature mirror grinding machine to print and use to make these optics from glass or plastic. The tube is incredibly wasteful of time and filament when printing, so you might be better off using a cardboard tube and adjusting the parts to suit, then only printing the secondary mirror assembly and the rear of the telescope. The interesting part of the tube segments is that they are printed with baffles over their entire length. Focusing is done with a simple rotating helical focuser. You may need to adjust your printer; with the 3D models I uploaded, it works very well if just a little tight, so a dab of grease makes it run nicely. In the pipeline is a mount for this telescope that can be used either manually or with motors. Purchased parts include: - A 150 mm diameter optics set of your choice - Two 150 mm diameter x 15 mm thick borosilicate blanks (one for the mirror and one as a tool) along with grinding and polishing materials - A 44 or 50 mm diagonal mirror - it's better to just purchase this one - Four M4 x 60 DIN 912 cap head Allen bolts - Four M6 x 30 DIN 912 cap head Allen bolts - Four M4 nuts - Four M6 nuts