This .scad will generate Cherry MX key switch testers of any length/width. The cutouts for the switches will be automatically centered.

Also included is cherryVoid.scad which includes a negative (void) space cutout of the precise shape you'll want when creating keyboard mounting plates, custom key switch testers (e.g. with text), and basically anything else you'd want a Cherry MX key switch hole.

Pre-generated key switch testers of varying sizes are also included.

UPDATE 20200302: The interior of the switch tester now uses rounded corners (no more sharp edges) and I've added an option to include a keyring/cord hole in the corner (makes a great keychain/fidget toy). All examples have been re-rendered and the 1x1 model includes the keyring hole.

Print instructions

Layer height doesn't matter much... Might as well go big!

Key switches should snap-fit right in

If your key switches don't snap fit very well try adjusting the TOLERANCE value in the .scad to something like 0.15 or even 0.2 (if your printer needs serious maintenance or just plan sucks haha). Another thing it could be is too much first-layer squish (elephant's foot). Either sand it off or raise your nozzle's starting position (or lower the bed).

For reference all the key switches I've tested (Cherry MX, Gateron, and Kailh) snap fit wonderfully.