Adjustable phone holder for afocal projection astrophotography

thingiverse

Notes update - Redesigned from scratch after a few test prints. The blocks on the edges didn't quite close around my phone with it aligned on the eyepiece. Also, it couldn't handle phones like samsungs where the camera was in the middle. This version should be a bit more useful. Background I am designing this for the Edmonton RASC observatory at the Telus World of Science, Edmonton. They hold public observing when the weather is good, and many people out for a walk in the park stop by. Invariably, someone wants to take a photo with their phone. Idea Since we can't predict just what phone exactly will be used, I have taken the design for the holder for the minikossel, and turned it into an astronomy outreach tool. This thing is intended to be used with an eyepiece in place already - it won't fit directly in the focuser. I have estimated that the 2inch eyepiece we want to use this with has about 2.2inches OD at the spot where the eyecup normally fits on it. A similar guess was made for the 1.25" version. I will refine those once I have actual numbers. Instructions I am planing to print this in black ABS. The inside of the optical path will be sanded with 60 grit sandpaper to eliminate internal reflections and add some micro-baffling. Nuts and screws will be needed for the sliders, I will probably use wingnuts or the like so it is easy to adjust. There are spots to add set screws to mount it securely on the eyepiece. This piece is designed with a camera in the upper right corner of the phone, like an iPhone. I tried to leave room for a fair bit of variation, but I haven't used many other phones, so I make no promises. The .scad file is parameterized and should be somewhat tweakable. The updated design does not have any lips to grab the phone - I plan on glueing on some craft foam-rubber sheet to make it grippy. I used some felt pads, but they are too slippery. The rubber bands should hold it in place. Both your phone and eyepieces could be damaged by using this, not my problem.