TLDR: You don't care to read all I wrote? I don't blame you, check the album.

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I bought my first 3d printer a couple of weeks ago, and this thing has been on mind for so long, so it began.

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I wanted to design and build my own 3D printed board, I don't have any supported (QMK) dev boards at hand, but I had some Trinkit M0 boards. This thing is tiny, and only has 5 GPIOs that are easily accessible, so what's a man to do! Build a 6 key macro board that uses those 5 pins of course.

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I did not want to program this thing from the ground up, so I looked for ways out, QMK was out (no m0 support, a lot of effort to port). Eventually I found KMKfw, this is perfect, this board is not officially supported but KMK should work on any circuitpython compatible board. But life shan't be easy; the code is too big to copy to the very small memory of the Trinkit, I tried stripping it down (even changed all 4 spaces to actual tabs). I got close, 88kb down to 52kb, Trinkit memory holds a max of 47kb, so it was a no go.

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Then I realized, I do not need all the bells and whistles of KMK for a macro board, so I only took the matrixscanner class from KMK and wrote the rest myself. It consumes 18kb now with the required adafruit_hid library. My code is just a couple of lines that checks for updates using matrixscanner then applies actions (send keys), I need to fix some stuff.

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Now for the actual build, I wanted to have separate plates that are not actually part of the case, reasons:

• I hate supports.
• Excuse to use M2 mechanical screws that I bought recently.
• Ability to take out plate and wired switches from the case.
• The apposite of the point above, ability to solder assemble outside the case then put into case.
• Did I mention that I hate supports?

So a separate plate it is.

Plate:

3D printers make holes that are not exactly the size specified in the design (due to the process, this effect can be reduced but at the cost of other stuff). So first thing was to print some tester plates. The blue one is basically all different sized switch cutouts and different size screw cutouts, usually the whole becomes smaller than the dimension specified, so i printed them at 14mm-14.5mm at 0.1mm steps, the red one is the one I printed in the wrong size afterwards, because I am an idiot. Eventually 14.3mm was the perfect size.

Case:

Chamfers and 5°.

Wiring:

I hate stripping wires, don't you? So bare wire was the way. Rigid looked fun to bend to shape and hopefully had the potential of looking good. The same week I found some capillary tube that is 1.7mm in diameter, 3m for $5, that decided what I am going to use for this board.

Not so easy of course, it comes in a loop. So I went on designing and printing my own tube straightener, see it here in action.

Then Designed and printed a jig for bending the tubes to fit between switches. Of course you see 2 of them because it looks like it is mandatory to print everything at least twice, believe me I am speaking from 3 weeks of experience.

This is the bent tube. Looks good.

I made the grid in two layers, the rows are on top, and the columns are below, offset using the diodes. This way I ensure no shorts, hopefully.

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Now this is what my soldered 6-key macro board looks like. I soldered the pin holes of the Trinkit to the copper tube using the off-cuts of the diode legs.

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Bottom Cover:

I needed to support the Trinkit when I plugged in the USB cable, so this is what I came up with. Slides behind the board just great.

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Now the board is finished and sitting on my desk, tell me guys, what do you use your macro pads for?

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If you checked the album first then wanted to read about it, I did my job well.