Sometimes you don’t need anything that fancy out of your printer to produce what your really need in the moment. ApacheXMD started with a length of vinyl gutter downspout and two mirrors. By printing this single printed part twice: a hardy periscope! Want one that is (much) longer? Cut the downspout to taste (and for what you can carry without falling over).
This is a periscope made out of two printed parts, a vinyl downspout from the hardware store, and two mirrors from the craft store. Print 2 copies of the included .stl file… It’s up to you how long of a periscope you want to make….”