I didn't like how the LEDs were so visible so I decided to make a diffuser to hide them when they are off and blend the light a bit.

My original plan was to use the same pattern out of laser cut polypropylene (chosen for its bendiness). This proved difficult because it is hard to glue polypropylene. I was able to weld it with a soldering iron but it was too hard to align everything in place. I then realized the best thing to do would be to vacuum form a shell directly on the mask. I learned first hand that vacuum forming over the mask without additional support would result in it breaking (fortunately only by a little). To give it support I filled the (foil covered) mask in expanding foam.

After trimming off the excess I vacuum formed it with 1/16 PETG. This ended up being too thin/soft and captured the outline of the LEDs. I applied another layer but it wasn't any better.

Not sure how to fix this, perhaps ABS or even thicker sheets would work.

After some trimming (soldering iron hot knife worked great) and spray paint:

Next is to work on the control board...