Buckling spring corne?
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- Location: Germany
- Main keyboard: Planck EZ
- Main mouse: Logitech M570
- Favorite switch: Kailh Copper Speed
Hi,
with the model f flippers and barrels now available for 1$ each... What would one need for a buckling spring corne?
Barrels - check
Springs and flippers - check
Plate - corne shaped, to be designed
PCB with capacitor pads, corne shaped, tbd
Controller for each side, tbd
I've seen https://youtu.be/dKhqcWgnE4Etor but I wouldn't want to disect working model Fs for that.
Unfortunately, I would start at nearly zero (I can solder and follow instructions, but that's about it).
with the model f flippers and barrels now available for 1$ each... What would one need for a buckling spring corne?
Barrels - check
Springs and flippers - check
Plate - corne shaped, to be designed
PCB with capacitor pads, corne shaped, tbd
Controller for each side, tbd
I've seen https://youtu.be/dKhqcWgnE4Etor but I wouldn't want to disect working model Fs for that.
Unfortunately, I would start at nearly zero (I can solder and follow instructions, but that's about it).
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- Location: Texas
- Main keyboard: Kinesis Model 130
- Main mouse: Logitech M-S48, Razer Viper
- Favorite switch: MX Browns
- DT Pro Member: -
You could 3D print a plastic barrel plates. That'd be the easiest way to get a curve.
No idea how capactive buckling spring PCBs work, but there are replacement F controllers which replace all the "scanning" done by the original PCB, so I believe it's fairly understood. Easiest way would be a flat PCB wired to one of the replacement controllers. Curved barrel plate + flexible PCB + bent metal backplate (with something similar to a bolt mod to attach it) might be ideal.
No idea how capactive buckling spring PCBs work, but there are replacement F controllers which replace all the "scanning" done by the original PCB, so I believe it's fairly understood. Easiest way would be a flat PCB wired to one of the replacement controllers. Curved barrel plate + flexible PCB + bent metal backplate (with something similar to a bolt mod to attach it) might be ideal.
- Weezer
- Location: USA
- Main keyboard: IBM F122
- Main mouse: Dell 0KKMH5
- Favorite switch: IBM buckling spring & beam spring
An xwhatsit will work with basically any capacitive PCB matrix you create as long as it isn't larger than 16x8. I think the easiest way for someone who doesn't have the ability to make their own controllers would be to buy two xwhatsits, and attach one to the right PCB and one to the left PCB you have printed up, and then run two USB cables to the computer, as if you had two keyboards attached.
I dunno about this. Unless 3D printing has advanced beyond what I'm familiar with, that seems like it would be very scratchyRayndalf wrote: 23 Apr 2021, 00:41 You could 3D print a plastic barrel plates. That'd be the easiest way to get a curve.
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- Location: Texas
- Main keyboard: Kinesis Model 130
- Main mouse: Logitech M-S48, Razer Viper
- Favorite switch: MX Browns
- DT Pro Member: -
Yeah, that'd be how I would do it anyway. Unless I wanted to wire both to the same matrix and shove it into one large case.Weezer wrote: 23 Apr 2021, 00:59 An xwhatsit will work with basically any capacitive PCB matrix you create as long as it isn't larger than 16x8. I think the easiest way for someone who doesn't have the ability to make their own controllers would be to buy two xwhatsits, and attach one to the right PCB and one to the left PCB you have printed up, and then run two USB cables to the computer, as if you had two keyboards attached.
Well the barrels themselves are injection molded, so 3D printing the barrel plate is just an alternative to having one cut out of metal.Weezer wrote: 23 Apr 2021, 00:59 I dunno about this. Unless 3D printing has advanced beyond what I'm familiar with, that seems like it would be very scratchy
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- Location: Germany
- Main keyboard: Planck EZ
- Main mouse: Logitech M570
- Favorite switch: Kailh Copper Speed
I think a flat plate would be the way to go. Given that the wcass controller boards seem to support qmk just fine, that would be my choice there.
Are the exact measurements of the "barrel holders" for the new F77 barrels available somewhere to be used with keycad to design the plate? I happen to know a "CNC guy" but he probably needs the CAD file for a quote...
Are the exact measurements of the "barrel holders" for the new F77 barrels available somewhere to be used with keycad to design the plate? I happen to know a "CNC guy" but he probably needs the CAD file for a quote...
- Muirium
- µ
- Location: Edinburgh, Scotland
- Main keyboard: HHKB Type-S with Bluetooth by Hasu
- Main mouse: Apple Magic Mouse
- Favorite switch: Gotta Try 'Em All
- DT Pro Member: µ
What's a corne?
If you are indeed talking about a split ergo board, I'd advise against using two different controllers. You wind up with weird gotchas like Right Shift + A = lowercase "a" that way, let alone more complex key combinations. Two controllers means two keyboards to the host. Some platforms merge all connected keyboards together, but not others.
As for capsense controllers: the gold standard right now is Pandrew's QMK port for Xwhatsit controllers (as sold by Ellipse). DMA's commonsense is highly regarded, too, and cheaper as it runs on commodity hardware; but more fiddly to configure from what I've heard.
If you are indeed talking about a split ergo board, I'd advise against using two different controllers. You wind up with weird gotchas like Right Shift + A = lowercase "a" that way, let alone more complex key combinations. Two controllers means two keyboards to the host. Some platforms merge all connected keyboards together, but not others.
As for capsense controllers: the gold standard right now is Pandrew's QMK port for Xwhatsit controllers (as sold by Ellipse). DMA's commonsense is highly regarded, too, and cheaper as it runs on commodity hardware; but more fiddly to configure from what I've heard.
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- Location: Germany
- Main keyboard: Planck EZ
- Main mouse: Logitech M570
- Favorite switch: Kailh Copper Speed
This is a corne - https://github.com/foostan/crkbd - it works with two serial connected pro micros of which one is the main connected via usb and the other one is the not-main one connected via TRRS cable. For keymaps and combos, it is one keyboard.
- Muirium
- µ
- Location: Edinburgh, Scotland
- Main keyboard: HHKB Type-S with Bluetooth by Hasu
- Main mouse: Apple Magic Mouse
- Favorite switch: Gotta Try 'Em All
- DT Pro Member: µ
Right…

Capsense (which is how Model F works) is trickier. There's nothing theoretically impossible about a twin-controller board, but it would need new work to make it happen. The controllers we've already made are all single.
Naturally, you don't want chunky cables running between your split ergo hands. A controller in each half makes sense. But they'd need combined. Unless you do want to slum it, act as two independent keyboards, and leave merging to the host; which also ruins what you can do in layers.
Capsense (which is how Model F works) is trickier. There's nothing theoretically impossible about a twin-controller board, but it would need new work to make it happen. The controllers we've already made are all single.
Naturally, you don't want chunky cables running between your split ergo hands. A controller in each half makes sense. But they'd need combined. Unless you do want to slum it, act as two independent keyboards, and leave merging to the host; which also ruins what you can do in layers.
- Weezer
- Location: USA
- Main keyboard: IBM F122
- Main mouse: Dell 0KKMH5
- Favorite switch: IBM buckling spring & beam spring
Windows unifies them and unix-like systems dont, but you can manually unify plugged devicesMuirium wrote: 23 Apr 2021, 10:26 You wind up with weird gotchas like Right Shift + A = lowercase "a" that way, let alone more complex key combinations. Two controllers means two keyboards to the host. Some platforms merge all connected keyboards together, but not others.
- Muirium
- µ
- Location: Edinburgh, Scotland
- Main keyboard: HHKB Type-S with Bluetooth by Hasu
- Main mouse: Apple Magic Mouse
- Favorite switch: Gotta Try 'Em All
- DT Pro Member: µ
How do you unify them, then?
Thing is: there's some stuff you have to do *on board* the keyboard. Example: function layers. If one half of your keyboard has your Fn key but the other half doesn't know you're pressing it, your function is no fn' use!
Thing is: there's some stuff you have to do *on board* the keyboard. Example: function layers. If one half of your keyboard has your Fn key but the other half doesn't know you're pressing it, your function is no fn' use!
- Bjerrk
- Location: Copenhagen, Denmark
- Main keyboard: Cherry G80-1800 & Models F & M
- Main mouse: Mouse Keys, Trackpoint, Trackball
- Favorite switch: IBM Buckling Springs+Beamspring, Alps Plate Spring
Depends on what you mean by unify. I have two keyboards (an AEKII and a G80-1800) on this Linux computer and if I hold, say, shift on one and type on the other, the characters come out as upper case, so the problem that Muirium describes doesn't occur. But with "keyboard internal" things like layers, I cannot - of course - hold the Fn key on one keyboard and expect layer toggling to occur on the otherWeezer wrote: 23 Apr 2021, 12:23Windows unifies them and unix-like systems dont, but you can manually unify plugged devicesMuirium wrote: 23 Apr 2021, 10:26 You wind up with weird gotchas like Right Shift + A = lowercase "a" that way, let alone more complex key combinations. Two controllers means two keyboards to the host. Some platforms merge all connected keyboards together, but not others.

The xinput output is as follows (there's also an IBM USB mouse attached):
Code: Select all
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ USB Optical Mouse id=15 [slave pointer (2)]
⎜ ↳ t.m.k. ADB keyboard converter Consumer Control id=11 [slave pointer (2)]
⎜ ↳ t.m.k. ADB keyboard converter id=13 [slave pointer (2)]
⎜ ↳ Bjerrk PS/2 keyboard converter id=16 [slave pointer (2)]
⎜ ↳ Bjerrk PS/2 keyboard converter Consumer Control id=19 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Power Button id=7 [slave keyboard (3)]
↳ Eee PC WMI hotkeys id=10 [slave keyboard (3)]
↳ t.m.k. ADB keyboard converter id=8 [slave keyboard (3)]
↳ t.m.k. ADB keyboard converter System Control id=9 [slave keyboard (3)]
↳ t.m.k. ADB keyboard converter Consumer Control id=12 [slave keyboard (3)]
↳ Bjerrk PS/2 keyboard converter id=14 [slave keyboard (3)]
↳ Bjerrk PS/2 keyboard converter System Control id=17 [slave keyboard (3)]
↳ Bjerrk PS/2 keyboard converter id=18 [slave keyboard (3)]
↳ Bjerrk PS/2 keyboard converter Consumer Control id=20 [slave keyboard (3)]
Last edited by Bjerrk on 23 Apr 2021, 13:20, edited 2 times in total.
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- Location: Stockholm, Sweden
- DT Pro Member: 0011
Yeah, Apple's HID implementation is known to be a bit different, whereas two keyboards should work fine on Windows and Linux.
You could start by designing it as a PCB per column but have them connected on the home row ... unless the traces would need to be a certain distance apart so as to not cause capacitive effects.
The thumb keys might also best be connected to the home row, I think.
I think it could be the most popular split columnar keyboard after the ErgoDox.
I think the PCB should also be curved individually per column.Rayndalf wrote: 23 Apr 2021, 00:41 You could 3D print a plastic barrel plates. That'd be the easiest way to get a curve.
You could start by designing it as a PCB per column but have them connected on the home row ... unless the traces would need to be a certain distance apart so as to not cause capacitive effects.
The thumb keys might also best be connected to the home row, I think.
It's even in the Wiki.

- Muirium
- µ
- Location: Edinburgh, Scotland
- Main keyboard: HHKB Type-S with Bluetooth by Hasu
- Main mouse: Apple Magic Mouse
- Favorite switch: Gotta Try 'Em All
- DT Pro Member: µ
So it is!
Regards capsense: don't worry too much about signal paths. Xwhatsit's own firmware used to be very touchy about all that (it used one threshold value across the entire keyboard) but Pandrew's QMK has separate thresholds for each key, like this:

Screenshots and links here. I've had a lot of fun with it. It's a breath of fresh air for fiddly boards like vintage beamsprings.
Umm…Corne, also knob as Heliodox
Regards capsense: don't worry too much about signal paths. Xwhatsit's own firmware used to be very touchy about all that (it used one threshold value across the entire keyboard) but Pandrew's QMK has separate thresholds for each key, like this:
Screenshots and links here. I've had a lot of fun with it. It's a breath of fresh air for fiddly boards like vintage beamsprings.
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- Location: Sweden
- DT Pro Member: -
I made this curved prototype a couple of years ago, split capacitive has been on my todo list for a while

(click for larger)
In my mind the thumb cluster would be a separate tilted board with ~2u keys, similar to this topre project.
You could do individually adjustable columns like that, but with a per-column curved PCB.
One problem is the lack of space for mounting holes between switches, I suspect you'd have a hard time getting enough rigidity with printed plates. Even with joined staggered columns the reduced overlap might be an issue, mine is just a continuous curve like the originals.

(click for larger)
In my mind the thumb cluster would be a separate tilted board with ~2u keys, similar to this topre project.
You could do individually adjustable columns like that, but with a per-column curved PCB.
One problem is the lack of space for mounting holes between switches, I suspect you'd have a hard time getting enough rigidity with printed plates. Even with joined staggered columns the reduced overlap might be an issue, mine is just a continuous curve like the originals.