This is a remix of “OnePlus 12 Case with Quad Lock and MagSafe Ring” uploaded by “lkapron”. I made quite a few design changes that I think make this much more 3D printing friendly, and more accessible:

• 45 Degree chamfered edges instead of rounded for easier printing without extreme overhangs due to curves.
• Two piece design so the case can be printed in hard materials such as PLA, PETG, ASA, and ABS.
• Added extra chamfers to the top corners of the button cutouts to prevent snagging on pockets.
• Extended the button cutouts down so buttons are easier to access.
• Pulled the outer edge of the bezel area around the screen out a bit so it doesn't cover any part of the screen.

• Flat back so designs, images, etc. can be added later on. 

   

I printed my case with the settings in the .3mf file uploaded here. (.16mm High Quality, normal supports, supports on bed only) @ 50% speed, and I used regular PLA. 

The top part of the case will snap on to the phone like any other phone case. The bottom part will slide on and lock in place with the tab.