My goal isn't to design a 3D printed case for a phone. Instead I want to create the Pip-Boy as if it were really made by Vault-Tec.
To that end, a game-accurate 3D model has been made from a variety of sources. A painstaking amount of engineering is put into optimizing the design for cost and efficiency, while trying to keep quality high.
The design will be printed using SLS Polyamide 3D printing. This was selected not only for increased accuracy, but is required to generate all the various internal features which hold the electronics in place.
The unit will assemble using real metal pins, and screws. A custom circuit board will interface the LCD screen to the DragonBoard 410c, as well as hold the other various custom circuits.
The Radiation Meter will be driven using a real gauge motor. A PIN diode gamma ray detector will be used to detect local radiation. (The meter can be driven from other source as well)
The FM radio can be tuned using the on-board knob. The control knob is geared down to a 3:1 ratio to simulate the old-school feel of a larger radio. The audio from the FM radio can be heard on the on-board speaker.
The holotape cassette deck is spring loaded with a push-to eject button. The holotapes themselves actually transmit optical data to the Pip-Boy. Using the same technology as a IR TV remote, the tape transmits a unique ID number to the operating system, which in-turn triggers an audio file or application.
A retractable USB cable is located at the back of the unit. The user can pull the cable out, which will lock in position. A tug activates the spring mechanism which retracts the cable back into the Pip-Boy.
I've been thinking of making one of my own and I'm considering using a bike tire in some way to fix the pipboy on my arm. Something like a pressure cuff at a doctors office, might even just use one of those. That way you can inflate it so it fits your arm. It will probably hold the right size too so you might not have to inflate it very often.