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Who can make a custom size spacebar keycap (for money)?

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I'm trying to build a custom hand-wired keyboard.
It is going to be based on Kailh Choc low profile switches.
It also needs 2 nonstandard width spacebars (4.25u).

Would anybody be interested in 3D designing and CNC machining (or 3d printing, but CNC is preferred) them?
I'm eager to pay both for design and making.

You probably can find some free 3D designs of keycaps here. Those wil need only an adjustment for width which is easy.

Getting it 3D printed properly is harder. Each method/printer has different errors and tolerances for keycap stems are tight. The method/printer errors will need to be compensated when setting stem dimensions.

And you probably cannot CNC a keycap at all. Is there a CNC machine which can do reliably 4 mm deep slot with width of only 1 mm and still keep tight tolerances. My guess is that this would need to be done by electro-erosion or some other process. Or you can blast hole through the keycap completely (e.g. with water jet or laser) and then patch the hole at the keycap top.

I would like to hear an opinion of somebody who works with CNC. I have experience only with reprap 3D printers only.

I'm actually not sure if it should be CNCed as well.
I'm not an expert in plastic/wood manufacturing unfortunately.
May be casted or anything, just that result is smooth for fingers to touch and precise enough to insert it into switch socket.

My advice, and your cheapest option.
Buy two spacebars, cut and glue them back together, I've seen people do this with cases and other parts, it can be done quite well actually. The best part is cost, you can get a pair of spacebars for $10 or less. My advice, try this first as every other option is going to be way more expensive. I would use epoxy and I would also fill in some of it, not just for strength but also sound.

Casting is somewhat a decent option
Couple downsides, you can't cast ABS or PBT, this means it will be resin, most likely polyester, but you could also use 3d printing resin (beware costs and fumes on all resin). The good side is you can cast in the texture. A major problem is cost, especially if you have none of the tools. Even if you don't, the amount of silicone and resins needed adds up insanely fast, casting is not cheap.

As mentioned 3d printing has tolerance issues (when you get this precise), but also strength and warping issues. Spacebars are notoriously difficult to make even with injection mold because of how plastic cools, ABS shrinks up to 8% as it cools and it and PBT both can warp if they cool unevenly, and since you have reinforcement ribs it gets really tricky. Milling could be used, but that will be extremely expensive, and it can still warp (you won't easily do this on a a cnc router). You could do resin 3d printing but while the warping would probably be less, it will still not be as strong and you once again have those tolerance issues, you also won't have ABS or PBT, but they do have some resins that have different properties.


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