I needed a new ceiling light for the entrance room, so I've designed and printed one. While the light is too small to be used as a main light in most rooms, it's perfect as an accent light - color LEDs would make for a great effect!
It's split in 4 parts for easier printing. The two hex shapes have a channel that lets you fit standard 5V LED strip inside. Everything routes back to the central hex shape (junction). The mount has two holes for attaching and then you simply screw on the main unit.
The tolerances are quite tight, so you should have a well calibrated printer before trying to print this. Although it should stay together with friction only, I recommend that you use super glue on all the contact points.
Do not attempt to use with mains voltage if you don't know what you're doing!