An old school rotary phone case that actually spins and snaps back into position (watch the video in the gallery above to see it in action).
This 3D printed case has a built-in coil spring that allows you to dial any number, and see the wheel spin back into place automatically. It comes fully assembled, but there are two things you should know:
1) You need to pre-rotate the wheel once by lifting the stopping tab and rotating until a bump in the wheel passes under the tab. See video for clear instructions.
2) You might need to remove excess dust from the printing process manually. The wheel might not spin smoothly until after all dust is removed and you use it a few times, but most of the time dust should be minimal and you won't have to worry about it. See video for tips on how to do this.