pca006132
I think you should probably use a CAD instead of graphics software to design…
Yeah WCH make some really cheap chips. Apart from ch552, there is also a family of BLE chips such as ch571f that is much more efficient than ESP32 (from online sources) and is very cheap. You can get the chip for half a dollar (https://www.aliexpress.com/item/1005005974200193.html) and a development board for less than 3 dollars (https://www.aliexpress.com/item/1005005974200193.html). When I bought it on taobao, it is actually around 1.3 dollars.
The downside is that software support does not exist (yet), so will have to try and make a firmware for it. I haven’t yet found time as I was working on manifold things.
Just in case it may help: https://lemmy.world/post/3373051
There were efforts trying to do make this simpler, but it was abandoned. See https://github.com/openscad/openscad/issues/4743 and related PR.
Indeed, the major cost is labor cost. I was iterating on the design once a month and do some very simple tweaking (change the screw location for example). Because I want to make sure that the entire thing works, I need to solder everything for each cycle. Due to the lack of components, I have to disassemble old working keyboard to make a new one. I probably disassembled 4 or more in total. I was looking to sell the old one for $100, but no one was interested. I guess a lot of mechanical keyboard users are probably not used to split keyboard and DIY keyboards, so are not willing to buy it.
Not sure about others, I tried to sell me keyboard but without success, maybe split keyboards are a bit too niche and no one near me (HK) is interested. I just disassembled the keyboars to scrap the components for the next build, which is a bit sad considering a significant amount of time is spent on assembling it.
For wrist rest, you can stick a piece of TU leather to cover the printed surface, so it will look nice, be clean and comfortable. Not sure if TPU is sufficiently soft if you want a soft wrist rest, you would probably need something like silicone.