This is a large aluminum key I made using the CNC mills for ME 318: Computer-Aided Product Creation

I really enjoy optical illusions and several of my project ideas had elements that were designed to trick the eye. I have some knowledge in miniature faking and tilt-shift photography, which are processes that can make cityscapes look like small models. One idea that intrigued me was to create a large version of an everyday object with a standard size, such as a house key. When the key is photographed next to other objects, a viewer would assume that the key is the proper size and everything else is just smaller. My project is a 6.25x replica of a standard Kwikset house key.

The key was modeled after a house key I bought, including the cuts for the pin heights. I added some details to my key, like the “do not duplicate” notice on one side. I spent some considerable time measuring the my purchased key with a pair of calipers and I was careful to model the cuts to match.

I milled the key from a large plate of aluminum using a face mill, a 1/4″ end mill, a 1/8″ end mill, a 1/16″ end mill, a 1/4″ ball mill, and a 1/8″ ball mill. I fixtured the aluminum to the CNC mill upon some sacrificial blocks and held it down to the bed with strap clamps. I had a part flip to machine both sides of the key. The key was held to the stock using tabs, which I cut with the band saw.

Overall, I like how my key turned out. There was an offset between the two halves of the key after the part flip, but after considerable filing, I was able to remove most of the remnants of the offset. It was great to see the key actually work when I photographed it with some furniture and made some quick adjustments in Photoshop.