Two part phone mount that clamps to vents on dashboard. You will need rubber bands to complete it to increase the grip.

There are 3 versions for different phone or phone case thicknesses: 8, 10 and 12mm, but depending on the edge profile on your phone, larger one could be more suitable. For example, version 8 works with iPhone-SE as is without scaling, but it could be made to work as well with 10mm and 12mm versions if the width is just right.

Revision 2 update

7.7.2023 - Added notches on the clamp and changed wrapping of the rubber bands to act as a friction fix. Now it relies way less on the clamping force and is more secure. Previous version had issues with air conditioning freezing the rubber band which could have caused the holder to loose grip and fall down when riding on bumpy roads.

Print instructions

Print without supports in the shown orientation. Print in PETG, ABS, ASA or something that can handle high heat. PLA will warp in a car during summer, annealed PLA might hold.

Customising the phone mount

You need to print Part2 - Holder in a way to snugly fit your phone or case, but not too tight to be difficult to remove so you need to modify the width for your needs. This might require some trial and error.

Option 1 in slicer:

Scale Part 2 along it's width in one axis only. It will still be possible assemble with the non-scaled clamp. The default useful width is 67mm, so measure your phone and scale proportionately.

Option 2 in slicer:

Use the measure and scale tool in Prusaslicer 2.6 to set the useful width of Part 2 to the size of your phone, then scale the Part 1 clamp by the exact same amount.

Assembly

Just slide the 2 parts together, they are push fit and should hold together well. Then wrap 2 rubber bands around the jaws like on the shown photos - make a cross at the back of the jaw and wrap the excess around the narrowed neck. It doesn't need to be tight.