added 50mm, turned object so you no longer need to rotate in the slicer, also made a bit bigger for better precision

simple 3 sided triangle thingie to check that your frame is square on your printer.
Yup, can use a box or what ever, but this uses less filament (and time) and, well it looks cooler ;)

Little write up on how to check with this and what having an out of square printer can do to your prints..

http://3dprintingllama.blogspot.com/2017/04/square-is-as-important-as-level.html

Print instructions

Category: 3D Printing Tests