So I got me a new Keychainino, a tiny charlie plexed keyring that comes with a breakout gamme. But I didn’t feel it’s 144 LEDs were safe when I shoved in in my pocket. Time to learn me some Freecad and sculpt up a case.
The Keychainino has been around for a while but the project had been quiet. But it popped up earlier in the year bringing back the v3 144 pixel version and I was on for that.
But once it was here I got reallu antsy about the density of the LEDs vs the junk in my pockets. And then there was the coin cell powering the whole thing around the back and well you never know.
3D Printing to the um…
Now I have been using my 3D printer for a while now, but generally its been other peoples designs being printed. I was always a bit leery of CAD software and FreeCad hadn’t done much to disperse that worry. But now FreeCad was 1.0 and if there was a time to learn it it was now. I was aided by advice from folks at HackWimbledon and this smashing FreeCad 1.0 Crash Intro which really got to the nub of how FreeCad things.
Iterate, iterate, irate
The next steps were “print something that is about the right size and then iterate”. That meant the first srep was a brick but it helped confirm my sizing in BambuStudio and Freecad was on the buttin.
Then we made the brick a little bigger and puched a Keychainino sized hole in it. And repeated the process. Printing again. This time the board didn’t fit cleanly with the battery underneath so another space punched in for the battery, we went for another print. And it didn’t fit right because I’d forgotten to long contacts on the battery holder. Another two 1mm punchouts and we were there.
And done
You can slide the Keychainino into the space we made, the battery is out of the way and it’s pretty stable, which is important when you have a breakout game to play. Freecad 1.0 seems to be a lot more amenable to iteration than previous experiences I’ve had with it but it is still quite the wall to climb - though more in terms of learning about designing than actually using the app itself.
Anyway, that’s my first actual thing designed and built, and now to iterate more. My next stop will be mastering pulling in other people’s STL files and modding them as I have a whole bunch of “nearly right” cases and then it’ll be on to casing up a Pi 5 + NVMe and touchscreen as a Cyberdeckish beast with a portrait mode default.
Have fun with the Keychainino case (it’s a fun little device and bright, so bright). You can find the files on Github at codepope/keychainino-case, fork and feedback!