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

[NiceBrat]

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.

[vvp]

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.

[vvp]

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.

[NiceBrat]

Yeah,
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.

[Leslieann]

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.

[NiceBrat]

Wow, Leslieann, thank you for such a great reply!

Yes, my backup plan is to glue spacebar from pieces.

I just hope I can find someone to actually make them.
I would even gladly open-source the results.

[yui]

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.

there seems to be a few peoples lately making CNCed metal keycaps, and full boards or fdm printed keycaps exist on this forum so both are valid option just cnc is going to be really expensive and you will likely get better result from cutting and gluing than 3D printing

[vvp]

There is a lot of keycaps 3D models around. I posted some myself(*), as well as 3D-printed them and shown the results. That is the easy part. They would not look as nicely as off-the-shelf standard keycaps. But you can improve them quite a bit if you are willing to sand them down to the required smoothness and paint them with acetone (if it is ABS) or paint with something else in the case of PLA (tetrahydrofuran works with some kinds of PLA but there are a lot of PLA varieties and it did not work with mine).

But I would love to see a machine CNC-ing 4 mm deep slot which is wide only 1 mm. I think there would be quite serious problems with the rigidity of the tool. If you have some links then please post. CNC-ing cases or even keycaps without the stem (and maybe glueing a stem from an off-the-shelf keycap afterwards) is not a problem at all. But the stem part looks like a real challenge to me.

(*) For example, here is one keycap 3D model I posted. I posted some other as well. Anyways, all of them will need a bit of tweaking because each FDM/FFF 3D printer will have somewhat different surface error behaviour and it will depend on the slicer and its settings as well. And a good keycap needs a very precise stem.

[yui]

https://metalkeyboards.no/our-caps.html
and
https://geekhack.org/index.php?topic=107611
are the most recent i saw, there was also a spacebar a while back

[Leslieann]

Wow, Leslieann, thank you for such a great reply!

Yes, my backup plan is to glue spacebar from pieces.

You're welcome.
I know it sounds cheap, but they really can work well if you do it right.

One thing I missed, once you glue one together you can either do it yourself (epoxy) or it will be much easier to find someone doing resin or even metal casting, keycaps, trinkets, whatever, and have them make a copy.

[vvp]

@yui:
Nice, and it even looks like it was done with vertical cutting tool despite the shape with open sides allowing to use some kind of cutting disc (rotating horizontally). A cutting disk should do the job much more quickly.