A simple device for checking the golden ratio. It has about 1.5 mm of play since the hinges are printed in one piece, but it is a fun to play around with and check proportions..
Orient the part so that the circular details of the hinges are facing up. Use support material for overhangs directly over the build plate. I found that a 30% fill for the support works good to keep the segments reasonably flat on the supported surface.
Once printed, remove support and work a blade in the part line around hinges until it can open and close.