Next I started working on the mounting plate. I was super worried that the plate dimensions wouldn't work out. I started off with this CAD which was imported from the Phantom .dxf files:
However, after checking out the Cherry MX CNC thread: (
https://geekhack.org/index.php?topic=65747.0;topicseen ) I realized that the design might not machine correctly depending on the end mill size.
I wanted to avoid having to draw my own sketch as much as possible, because then I wouldn't be sure if the holes would line up with the phantom, but I had to go for it and trust the math. This is the design I came up with:
You can see the half circles on either side, which allow for the tool to go all the way to the edges and not leave a rounded corner. The diameter of the extra semicircle is 1/16th, which is the size end mill I would be using. I needed to test this (and the layout), so I got some 1/16th acrylic (about this thickness Cherry prescribes for its mounting plates) and laser cut them:
As you can see the switches seemed to fit just fine. As a side note, the reason I used a 1/16th instead of something like 1/8th, which would have fit, was because I wanted to make the material in between the switches as thick as possible to make the plate stiffer. This means I'm in for a long ride because a 1/16th end mill will have to go pretty slow because the CNC I'm using has a maximum spindle speed of 8100. (The smaller end mills want to spin as fast as possible to reach higher feed rates). With that spindle I'm looking at 8 ft/min, which means cutting this thing out will take around 5 hours.
More on that soon!