Gear Tuner Button

Full Disclosure: This specific design is un-printed

The hole for the shaft was used in a different model I did print. It was tight but functional on these tuners:
Kmise A1966 Acoustic Guitar Tuning Key
And it may well fit others.

Due to the angles in vertical position resolutions of 0.06 or higher will make this the smoothest. I would go with 3 walls for hole strength.