Ukelele Friction Tuner Replacement Washer

Disclaimer: I AM NOT a luthier (craftsperson who makes and repairs stringed instruments) and this is probably NOT a very good repair. If your ukelele breaks, talk to somebody who knows about fixing instruments, not a computer scientist who has a uke and a 3D printer.

I have a ukelele with probably little monetary value, but sentimental value and practical value to me. It's probably on the high-end of "souvenir ukes", in that it's really rather playable (as far as I know, which isn't much), but has "Hawaii" printed on it along with some wooden dolphin cutouts glued on the body, and fishing line around some of the tuners to use to hang/display it. A piece broke, and this is the replacement piece I printed to keep it playable longer.

This "thing" may also serve as a reasonable introduction to some basic OpenSCAD concepts, since the .scad file is heavily documented, both for easy customization, as well as for instruction.

On this particular uke of mine are what are known as "friction tuners" for the strings: there's a tuning key for each string that just goes straight through to the front of the uke head directly turning, to tighten and loosen each string, no gears involved. All that holds the tune with these particular tuners is the friction between a slope on the base of the plastic tuning key/knob and a rather special-looking (and I'd guess nylon) washer sandwiched between that key and the back of the headstock. That washer on one of the tuners (G, not surprising to me since I had the hardest time keeping that string in tune) just cracked into two pieces, so I measured a combination of the key surface that was now easily accessible, and the other washers still intact, to design a quick and easy printed replacement.

So here it is - the replacement part I needed for my friction tuner.

Note: After looking around at search results for "uke friction tuners" it does appear that there are a wide variety of designs, and thus the highly adventurous could probably use this as a starting point to re-design/replace both of the plastic parts of the tuner, to potentially provide a nicer tuning experience.

Updated to have a better "Customizer" experience. Still probably easiest to download and edit locally, but now I even have parameter validation in the customizer.