The Cosmic Key

I've wanted a Cosmic Key since I saw Masters of the Universe back in the '80s. I still think it's one of the coolest movie props ever.

A couple of months ago I finally decided to make one. I designed the parts on my computer using Blender, going through several iterations of the keys - printing and assembling single keys as I went - until I landed on a design that worked.

I also spent a while figuring out how to build the cylinder that holds the keys. I ended up using stackable rings that could be glued together. Though when I make the next key, I will spend more time and figure out a mechanical way to attach them instead.

I used a resin printer for the key caps and forks to get smooth results with minimal post-processing. I generally use an FDM printer for structural parts since resin tends to be more brittle. However, I've been using an “ABS-like” resin that produces more resilient pieces, so maybe next time I'll use resin for more parts.

The original prop alternates key colors, so I used metallic spray paint: gold on the first half, copper on the rest.

I then glued the resin-printed keys to the FDM-printed key assembly. That was a mistake. The glue ran a bit and fused a few keys so they no longer press. I'll redesign this for the next version so the caps are removable.

I set up the “umbrella” mechanism with a lead screw nut so I could eventually motorize a lead screw to raise and lower the forks. For this first build, however, I decided to skip the electronics. I’ll revisit that in a future version.