Same as I did with my Pocket Synth Briefcase, I've decided to go with laser cut panels made by Cotter, a local laser cutting lab located in Copenhagen. I've used SketchUp Pro, which supports exporting to DWG, DXF and some other vector formats. Unfortunately, SketchUp Free lacks this feature, so unless you want to pay $590 to keep using SketchUp Pro after the trial period, you only have one month to complete the design.

I've chosen to use birch plywood, 9mm for the box and 3mm for the interior panels. Plywood is really easy to work with, but it's pretty heavy. The total weight of the panels ended up being around 6kg. I think it would be possible to reduce the thickness of the exterior panels down to 6mm and that would tangibly reduce the weight while still keeping the box strong, but then I would have to be more creative about mounting hinges and overall assembly.

Remember I've mentioned load balancing and the keys panel shape in the previous step? On the first picture, if you imagine the yellow section moving up together with the keys panel, you can see the panel acting as a hook latch. Also, this funny arc shape in the bottom of it is not just a visual decoration. If it was a straight cut the panel won't be able to move - it's a circular motion!