Lightning McQueen Car Keys

One day, I noticed that my car key had a crack on the bottom and I got the idea to rehouse the internals in a custom 3D printed enclosure. I thought it’d be funny to have car keys in the shape of a car and when I came across a little Lightning McQueen Hotwheels at the supermarket, and confirmed it was about the right size, I knew what I had to do.

KA-CHOW

Disassembly of the car key was pretty simple. Most small pieces of electronics these days are housed in snap fit enclosures, and sometimes screws. Mine had no screws. All I needed was a small flat head screwdriver and an old debit card (don’t use your current cards and mangle the edges) to press in the tabs and pry it apart.

The Hotwheels on the other hand was riveted together. I think (I’m writing this article 2 years after it happened) I drilled the rivets then pried the whole thing apart. Then I went in and ground off the posts and other features within the toy to hollow it out and accommodate my car key electronics. During this process, the hood caved in where a rivet post used to be. I was able to recover a circular piece of printed plastic and glue it back in place but after a while, 3 holes formed where I’d removed material and I’ve lost the printed areas since.

I designed a base that lets the original wheels and axles to snap in because the ability to roll around like a Hotwheels was very important to me. The battery holder had to be a separate piece, so I added notches and rails to guide it into place. The button labels “KA-CHOW”, “UN-CHOW” and “BOOTY-CHOW” correspond to “lock”, “unlock” and “open the boot” respectively. They’re a reference to Lightning McQueen’s iconic catchphrase. The design of the base took quite a few tries to dial in but it was great.

Retirement

Just like in the 3rd movie, my car key had to retire. Well, to be honest with you, it just stopped working one day. Not sure why, it wasn’t a battery issue. Had to pay up a big sum to get it replaced but it was fun while it lasted.

I don’t suppose anyone would want to recreate this project exactly, but if you want to modify my design, I uploaded it onto Printables. It was always a fun little tangible gadget to show off my design skills. Highly recommend.