I had already designed a mount for my iPhone 12 when I saw the one designed by falconphysics. I resized parts and redesigned the clamp for the scopes so that the jaw was captured in the frame. I also used threaded rods in place of the printed screws and used a rod and t-nut to join the frame and the phone mount. The 1/4-20 threaded rod for tightening the frame to the scope has a slot filed so that some tiny metal screws can retain it in the jaw. All the knobs are threaded for the rods and a little glue can be added when screwing the rods into the knobs, although just tightening them snugly will probably be sufficient.

My telescope required a spacer to get the phone high enough. If a spacer is required for your equipment, you may have to size to your requirements. I made a separate rod and knob for using the spacer. Be sure that the rod does not pass completely through the t-nut when the frame is tightened to the phone mount, since that could damage the phone.

My phone has a case and the jaws of the phone mount are for the iPhone 12 with the Otter BOX Defender Pro case. The Sketchup Make file has been included for easy modifications to the design. The jaws that hold the iPhone are separate groups and can easily be replaced or resized for most phones. Be sure that you include a recess for the buttons on the sides of the phone so that the buttons are not pressed when clamping the phone into the mount.