Car Key Cover
One day, a colleague approached me, asking for help. He'd just bought a new old car and the key cover was - as is often the case - ruined. Reprogramming the integrated steering lock chip was ridiculously expensive so he wondered if I could design a new 3D printed housing instead. He wanted something original looking and I wanted to give it a smart locking mechanism.
The end result is a two-piece laser sintered housing. The chip is placed partially inside the designated cutout so that it stands out too much on one side while being flush with the key body on the other.
A special groove allows the key to slide inside the housing with the chip in "travel position".
Once those parts are in place, a smaller printed cover with a wedge tip is inserted in the slot the key came through in.
The wedge nudges the chip down into its intended position and, upon reaching the end position, secures it in place. As a result, the chip sticks out on the other side of the key and thus into a pocket desiged to arrest the housing in place. The chip can't be pushed back out again, either, as the wedge/cover prevents that from happening.
Personally, I'd have preferred a smooth finish but my colleague said he preferred the grippy surface.
Be that as it may, a small, durable and quick solution.
