I wanted a modular way to hang my hats on a door vertically. Other models I saw had two issues I didn't like that I think I've addressed in this model:

• Trouble printing as the parts weren't sitting flat against the print bed due to the part flaring out. I could have rotated and used supports but I wanted a simple flat part.
• Much wider than necessary. I reduced the width by about 30%.

The 2 STL files are named door-hook and extensions. You need to print 1 door hook part and as many extension pieces for the number of hats you have. The "hinge" holes are 1.875 mm in diameter so a 1.75mm piece of filament works very well as a pin. Just clean the holes out first or you may not be able to get the filament to slide through easily.

To assemble, heat the end of a piece of filament and squish down the end so it forms a flat head. Put the filament in the hinge and trim the other end of the filament. Repeat the heating of that end to flatten out and voila....you just created a pin rivet. An alternative that should work but I haven't tried is to put a paperclip through the hinge and bend the ends. NOTE: The picture I posted only shows the filament before trimming and flattening the ends.