Over the years I have accumulated many of these wall socket voltage transformers. These are handily little things that can be easily repurposed. The problem is they get all tangled in a box. This Transformer Wire Winder will keep them without tangles and prevent damage to the wire. Also, if you travel, they make it much nicer to put in your suitcase.
The arrow on the ‘face’ is something I could not resist. IMHO winding the wire always in the same direction helps preserve the wire. Also, I like the ‘face.’ If you do not want to see the face do not make a color change at the 3rd layer during printing.
The Winder has a PLUG SIDE and a BLANK SIDE. The 2 sides need to be epoxy glued together, which is made easy with the 3 indexing pins. Splitting the Winder into 2 parts avoided printing with supports.
The 110-volt connector is designed like a wall socket, there is an internal gradual pinch the grabs the pins.
I suggest printing at a 0.2-layer height. PLA or PETG works fine.
Also, if you want to be super organized, color-code your transformers i.e. red 5 volts, black 12 volts - use your imagination.