iPhone models supported: iPhone 7, iPhone 7 Plus, iPhone 8, iPhone 8 Plus, iPhone X, iPhone XS, iPhone XS Max, and iPhone XR.
These are low profile cases with smooth contours. The models are designed to print reliably, and should be a very durable solution.
The specs for each phone were taken directly from Apple's published drawings for making compatible iPhone accessories. I have been testing various designs for about two years, and have printed dozens of cases that I have tested in that time. The models are pre-scaled to precisely snap onto the phone.
*iPhone 8 Note: The 8 (and 8 Plus) are almost (within 0.2mm) exactly the same size as the 7 (and 7 Plus). Use the 7 models for the 8. Scale the 7/7Plus models in your slicer to get the best fit for an iPhone 8/8Plus: Height(Z) = 102.82%; Length(Y) = 100.07%; Width(X) = 100.30%.
My original designs, from two years ago, are at https://www.thingiverse.com/thing:2327392
28-Jun-2019: Expanded XR camera opening to include the flash and microphone.
PETG has been the best material for phone cases. PLA is OK but it is not as durable.
Use 3 solid bottom layers, 2 solid top, 2 perimeters. Resolution 0.2mm. Infill 25% Grid.
On a cool PEI build plate, apply a thin layer of glue stick near the case perimeter. The glue stick helps to prevent warping. Set the build plate temp to 90c.
To remove the model: I slide dental floss under the model while the build plate is still warm. This helps to prevent damaging the case if the glue works too well.