In order to block as much as possible ambient light from surrounding civilization I've designed this Ambient Light Protector for my Levenhuk Ra 150C Cassegrain telescope.

It's push to fit design. Also the original cover fits well when you turn it around and push easily at the and of the tube.

I used a generic black PETG as I was a little worried of Prusa's black which contains tiny reflective particles. Although it generally improves the part's look, it might not play well with the incoming photons :) PETG choice for higher impact resiliency and better flexing of the push to fit parts.

Printing instructions:

Printer: MK3S+, or any FFF with at least 180x180x185mm printing area

nozzle: 0.6mm (or 0.4mm)

filament: black PETG

perimeters: 4

layer height: 0.3mm

no supports are necessary

Enjoy :)