This is a solar finder. (Always use appropriate filters when observing the sun!)
I designed it in small enough parts, so that I could print it on my resin printer.

There are now 3 Versions of the target:
- Original version ("Solar_Finder_Target.stl"): This version should be considered experimental! The printed spring should work with the right resin. It needs to be tough an remain flexible. Maybe a nylon-like resin might work? Be very careful when you remove the support, or you will break the "spring".
- v2 ("Solar_Finder_Target_v2.stl" and "Solar_Finder_Frame_v2.stl"): This doesn't use any springy part. A bit fiddly to adjust, because you always need to turn 2 screws at once.
- v3 ("Solar_Finder_Target_v3.stl" and "Solar_Finder_Frame_v3.stl"): This uses a spring from a ballpoint pen. A bit fiddly to assemble, but works great. I sourced the spring from a BIC ecolutions ballpoint pen. This spring has an outer diameter of 4.5 mm and a length of 25 mm. I also put a small piece of a toothpick (diameter about 2.5 mm, length about 12-13 mm) inside the spring to give it some lateral stability. Sand down the back side of the target until it freely slides.

You will also need:
- 0.7 mm drill (to clean out the pinhole)
- 5 mm drill (v3 only, to clean out the hole for the spring)
- 6 mm drill (to clean out the holes for the connecting rods)
- M3 tap

- 2 x M3 thump screw
- 6 x M3 set screw
- 2 x 6 mm rod, steel or other stiff material, approx. 200 mm long
- v3 only: spring, approx. 4.5 mm x 25 mm (e.g. from a ballpoint pen) and a small section of a toothpick or something similar

Print this with a tough, engineering type resin. (I used Eono ABS like resin from Amazon.)
It should also work with a filament printer.
 

Category: Physics & Astronomy