Mandolin Tuning Machine Buttons (aka Tuner Knobs) - Waverly Style

The tuning machine buttons on my Kentucky KM-505 Mandolin started to crack, and a decent set from StewMac runs about $64+shipping ( $8 x 8 buttons). 

FYI, you can buy a complete set of low-end tuning machines with buttons for about $50,  so I designed a replacement. 

Waverly Style Tuning Machine Shafts: 
These buttons fit a shaft that is 3.75mm (0.145") in diameter. The flat portion is about 2.9mm (0.115") across the flats and 8.9mm (0.35") long. A fine screw (maybe a 2-56 screw? it's 2.25mm or 0.86" in diameter) holds the button in place. 

Two Model Versions: 

1. one with the support built into the model. No additional support required. 

2.  one with just the button, so you can use your slicer's support function

Print Considerations: 

White silk PLA has a similar look to the fake “mother-of-pearl” plastic normally used in tuning machine buttons, but you could have fun with some different filaments for sure. 

Recommend printing with 0.1mm layer (or better) and print them with 100% infill for maximum strength. 
 

Post-Processing:

These were printed with a 0.6mm nozzle and I did zero post processing. They work perfectly and look just OK, but with a little sanding and a coat of clear finish, these could turn out really nicely.  

I actually designed these a couple of years ago and had one ugly gray PLA knob for a few years, which held up very well.