There are quite a few 3D scanning apps available for iPhone X, XS, and XS Max that make use of the FaceID cameras. Unfortunately, because they use the front camera it's quite difficult to get a good scan without being able to see the screen. There are various parts available that use a mirror assembly to make the process more convenient but I find they degrade the scan quality due to not being 100% reflective or scattering the dot projection.
These apps all make use of the gyro to know whether they are being rotated around an object and so a stationary phone holder with a turntable for the object won't work.
Hence this monstrosity was born.
It keeps the object stationary while you rotate the phone around a path. It seems to work pretty well. As an added bonus it even folds up for storage!
Apps I've tested it with:
I've also added a phone holder that has an offset mount so that the rear camera can be used with various photogrammetry apps such as Trnio.
To complete the project you will need the following:
3 x 608ZZ skateboard bearings
5 x M5x25 bolts
5 x M5 nuts
A board or something to fit under the object on the platform
Please note, I don't have an iPhone X, only an XS Max and so I had to go by Apple's measurements for the X holder. If you make this one, let me know in the comments whether it fits properly.
Any Doesn't matter
Bearing holder requires supports. All other parts do not.