Thank you such much everyone for your feedback!
It's really encouraging to hear your interest, even if this an unusual design that you wouldn't use yourselves.
Replying to fpazos:
The ergo community is a niche inside a niche. And people go very strong on their preferences, starting with no one really needs / goes over a 50% layout and most of the users only like the 40% keyboards.
My core idea really is to try and improve on where the Alice currently is aiming. Several companies are making Alice boards, so there must be some demand there - and yet it's just a franken design (in my opinion) that tries to improve ergonomics but doesn't really hit the spot.
Imagine a keyboard you'd give to your mother-in-law, or put on the desk at home for your spouse/partner and children. I feel I can't replace the keyboard at home with a 40% Dactyl!
Replying to fpazos and Leslieann:
I'm quite interested in the idea of using 3D-printing to produce the bending die, to make the bent metal plate. That's not something I'd considered.
I think that with steel dies, getting extremely accurate bends would be possible: at the end of the day, you can empirically measure the k-factor for each bend, and the springback, and just keep tweaking the plate until you achieve accuracy. The dies will then ensure consistency. If you assume an initial k-factor of 0.45, then the actual k-factor is going to be around 0.425-0.475, which gives a variation for the bend allowance of less than 0.1mm. So basically fine-tuning the bend allowance won't buy you much additional accuracy over your process error anyway.
I _have_ rendered this with switches and caps, and designed carefully accordingly. The FreeCAD design is fully-parameterized, with all the parameters (stagger/recess/splay, per column), and there's a big spreadsheet with a ton of trigonometry to get all the positions accurate. The base of the keycaps is 5mm above the plate, and the keycap bases are laid out on a 19.05mm grid, then the plate is offset below that.
The concave bends (such as between Z and A, and Q and 1) work perfectly. The convex bends (such as between Ctrl and left-shift) don't quite work, there will be a gap there. That's because you need to allow both keys to be pressed at once, meaning the keys will travel apart as they come up.
How much are you planning on spending on this, for yourself or in a group buy?
Very good questions! I have fairly good experience of woodwork and metalwork myself (in my shed), but very little experience of sending stuff out to be manufactured. I admit this is a bit of a problem.
I hadn't considered milling the plate at all - because I was planning to build it myself at home, and then move to CNC only if there was lots of interest. As you say, there are big fixed costs (of time and money) sending something off to be manufactured, so if it's just 1 or 5 units I was going to avoid CNC at all, and just hand-build the case and plate.
Don't expect customers to hand wire if you decide to make more.
Yes, agreed! I've made a couple of PCBs by hand (in an acid bath, printing off a mask using an inkjet printer etc). But never sent one off to be made.
Have you seen the amazing PCBs for the Charybdis (Bastardkb)? Very, very neat. He describes in a post how he did it: using a thin PCB, and using experimentation. Offsetting the plate dimensions to get an initial PCB, but then fine-tuning the allowances for each bend by experimentation (sending off for another tweaked PCB...) until the pins lined up exactly with each hole in the bent PCB. Sounds pretty hard work.
So - I think for a Dactyl it's either going to be: handwiring, single-switch PCBs (Amoeba), or something like Bastardkb's designs.
Honestly, especially on such a small keyboard, a 3d printed plate is plenty stiff and strong if designed properly
That's a fascinating idea. I hadn't considered printing the plate either. I've never 3D-printed anything before, and I certainly don't have budget to get one myself, but it looks like there are services where I can send an STL file and have it printed for reasonable cost. My metalwork experience is from >10 years ago, and predates 3D printing and CNC, and was mostly on hand-lathes and mills! I would gladly buy a hand-mill over a 3D printer if I had budget for either. ("Budget" here refers to spouse approval as well as absolute cost!)
I found your post on the PF65, it looks an awesome DIY project!
Thank you again everyone for your thoughts.