"Subtraction" Block for Use in the Design of 60% Keyboard Cases

April 30, 2022

Description

This is a "negative" block used in the design of standard 60% tray mount keyboard cases. It is used to subtract a tray cavity/well from your case design. The PCB/plate will rest inside the tray that you have carved out using the block.

(I use Microsoft's 3D Builder to start most of my designs, because I find its geometric primitive approach more intuitive than Fusion 360, at least in the early stages of the design, which explains the use of Boolean subtraction to create the trays in my cases. 3D Builder lacks a lot of features, however, so I would still generally recommend Fusion for most use cases.)

The dimensions of the block are approximately 286.25 (L) x 95.75 (W) x 20 mm (H), which is slightly larger than the GH60's plate dimensions of 285.752 (L) x 95.252 mm (W). I find that these measurements produce the right fitment on my printer; they will allow key presses without interference with the sides of the case.

Given the differences among printers and filaments, however, these exact settings may not provide the best fitment for you, and you may need to conduct some experimentation. I've found that with 3d printing, small changes in the manufacturing process (in contrast with the design process) can have disproportionately large effects on the ultimate print, and that the adage, "measure twice, print once," does not always obtain with 3d printing. Even the ambient temperature can affect a print, as I discovered this winter, when my cases shrank and I could no longer fit PCBs in them until the weather warmed up again.

Note that, for simplicity, this model does not include standoffs or a "subtraction" model for the USB port. If there is a need for those features, I will post another model on Thingiverse.