Introducing the new Mini Ukulele Tuner. 25% smaller than my [full-sized soprano ukulele model 3 tuners](https://www.thingiverse.com/thing:6779545), but strong enough for long term use and holding string tension.
I use these Mini tuners on my [Mini, sopranino sized, pocket ukulele](https://www.thingiverse.com/thing:6746101).
Tuner Parts
Each tuner consists of a base, a cover, a gear, a worm gear and a tuner knob.
In addition to the printed parts, you'll need two #2 3/8 inch wood screws for tuner installation. The equivalent metric screw is M2x8mm.
There are two versions of the worm gear, one with a 2 mm hole in which a 2 mm carbon fiber rod can be inserted for extra strength. The worm gear without the hole and carbon fiber rod is plenty strong for tuning the ukulele. But if the uke is dropped or knocked over, then the worm gear can snap right at the edge of the base and cover due to the sharp shock. If you are not clumsy (like me!) then the version without carbon fiber rod is fine.
Printing
I print all parts with 5 wall loops, 100% infill, and rectilinear infill pattern. For extra strength and help holding string tension, I print the gear at a 45 degree angle. This requires supports.
Filament
I use PLA or PETG. I recommend avoiding filaments with additives, such as PLA silk, matte, or wood as these often have much lower strength. Bambu PLA basic has a bending strength of 76 MPa and tensile strength of 35 MPa according to Bambu Lab's Technical data sheets. I have found that filaments with similar or greater values work well.
Tuner Installation
The video below shows the installation of the tuners. Although this was made for the full size model 3 tuners, and shows installation on [my soprano guitalele](https://www.thingiverse.com/thing:6943916), the procedure is the same for the Mini tuners.
jwnicholson
