Butanizer - rotatable dihedral angle visualizer

As a TA in organic chemistry in 2013, I made a butane with a molecular model kit and attached two pieces of cardboard with scotch tape as a visual aid for students to learn the concept of dihedral angle. I nicknamed it "butanizer" later on. Then I decided to make a 3D printable model so voila! The butanizer is rotatable and a great tool for organic chemistry learners to visualize the dihedral angle between the C1-C2-C3 and C2-C3-C4 planes and what anti, gauche, and eclipsed conformations look like. This model is roughly to scale: 3 cm = 1 angstrom.