Custom keyboards and input devices have become something of a rite of passage in the hardware hacking world. These normally involve off-the-shelf keyswitches, encoders, buttons, and the like, linked up to an HID-capable microcontroller, and fed into a computer as either a full keyboard or an auxiliary input of some kind. James Stanley, though, wants to do things a little bit differently, and 3D-printed the mechanical keyswitches themselves to take customization to a whole new level.
It’s definitely a challenge, as these switches have to stand up to a rather massive amount of use day after day, and have to be made quite small. Nonetheless, Stanley has come up with his own functional switch design, and in order to experiment with it he's also made an automated keyswitch testing machine. This 3D-printed unit employs a micro servo to press on the switch over and over, under Arduino control. Servo positions are intermittently changed, with positions recorded based on when the contacts close and break, giving him quite a bit of data to analyze.
The tester features an interchangeable key holder, which was used to successfully test around 23,000 keypresses from a knockoff Cherry MX Blue switch. When he swapped it out to test his own printed switch, however, it broke after 13,907 activations. That might sound like a high number, but as he elaborates in his failure post, this could mean space bar failure after less than 2 hours of (impressive) 120 WPM typing.
Still, it’s better to know this now than to construct a whole keyboard for just a few hours of fun, so hopefully he’ll be able to improve and make something truly awesome! Code and print files for the tester are available on GitHub.