I recently broke one of the tuner's knobs of my guitar and print a replacement...
There are some little holes to reinforce the internal structure of the hole, to make sure it will not shear if the knob is a little tight to turn.
The bolt diameter is 4.2mm and the knob fits tight and have to be pressed on, it is not a fault, it has to be a tight fit.
I created these links where you can find all common filaments and spare parts at the best prices. These are just links to selected eBay and Aliexpress items, where I normally buy spare parts and materials for my printer, prices are excellent and products are good. If you buy something from here you will support me a little bit to make these projects.
Remember to come back and post what you've printed as Make.
It's good for the designer and the community (that means you)!
To post a Make, come back to this Thing and click Post a Make.
Or, you can use the Thingiverse Mobile app found on
and the Apple App Store.