You've seen this Instructable before; turn a length of PVC into a periscope with a few mirrors

https://www.instructables.com/id/PVC-Periscope/

Most step-by-steps have you modify 90 degree elbow fittings so they hold mirrors at 45 degree angles.

Success hinges on how precise you hack the 90 degree elbows apart and insert or glue the mirrors in place. With the help of a 3D printer your periscope is perfect every time. This fitting might also provide some more flexibility in the type of mirrors you can use.

Step 1: Assemble Materials

For this project you will need:

A length of 2" Sch 40 PVC pipe (the length isn't critical but 2-3 feet is manageable)
Two hand mirrors (like these: http://amzn.com/B000RZQI68)
A hand full of rubber bands
Access to a 3D printer and the attached files

Periscope.stl
Download View in 3D

Step 2: Design a Fitting.... or Just Download This One.

You can design your own fittings to work with whatever size pipe you want, but if you're content to use 2" PVC, I've done the work for you. The file can be downloaded on Thingiverse!.

http://www.thingiverse.com/thing:1027744

Step 3: Print 2 Periscope Fittings

The footprint of the fitting is about 3.5" x 6.0"

You'll need a 3D printer that has a print bed at least that size (most do)

Print two!

Step 4: Place the Mirrors

The mirror I used for this project is 2.75" x 4.25".

I got it on amazon (http://amzn.com/B000RZQI68)

But....any size or shape of mirror will do, just make sure it covers the oval hole in the fitting

Step 5: Attach the Mirrors

The rubber band system allows for flexibility (pun unintended).

Make sure the mirror is flat and then just strap it down,

Use as many rubber bands as you feel necessary to secure hold each mirror in place. I used four for each mirror and would recommend using at least that number.

Step 6: Attach Fittings

The fittings should press onto your PVC pipe with enough clearance to allow you to twist the fitting but not so loose that it will fall off. Print at 100% at first but try 99% or 101% if you need a tighter or looser fit.