Bracket is 33.3mm of diameter, based on my bike's stem (the bar connecting the handle bars to the bikes frame). If yours is different, adjust it as needed.
There isn't much to talk about this projects, just check the pictures. Make sure your phone isn't too large for it. I made it for a Samsung Galaxy S8 and Galaxy S7, but it fits different phones as well.
Hardware: 2 M4 nuts.
2 M4 x 10mm (at least) bolts
Besides that, Instead of posting the detailed printing settings, I uploaded the .3mf file sliced on Cura. You can use it and change whatever you want.
If you'd like to support me you can post a make, comment and/or pay me a coffee at PayPal