koda keyboard - 4x12 grid using kailh lp switches and Family 13 keycaps

Are Signature LP Family 13 keycaps are a viable solution for kailh low profile switches? Here are some of the issues:

1) The Family 13 keycap stems were designed for cherry ML, which is .2mm wider than kailh low profile switches. However, this leads the keycaps to pinch the kailh switch housing, so it actually works better than expected.

2) The Family 13 keycap contacts the top side of the kailh low profile switch, which can be a detriment depending on one's typing style and fingertip sensitivity.

3) The spacing is different; Family 13 keycaps were designed as replacements for the Cherry G84-series, meaning that they are 18x18mm. So any boards designed specifically for kailh keycaps, which are 17.5mm x 18.5mm, are incompatible. Any boards that are standard 1u (combined mx/alps/choc footprint) should work, but the keycaps will have gaps and will be slightly offset.

Testing a switch by itself is not a representative test. Thus the Koda keyboard was made for science.

koda keyboard with preferred layout

glamour shot with the standard layout - color codes BFJ and NN

So what's it like? The keyfeel at the bottom of the keycap is not crisp and clean due to the contact with switch housing, but functionally they work. The best description I have is "muted". Personally, I don't mind it at all since I prefer clicky switches for typing. However, fans of linear switches who use their keyboards for gaming might find bottoming out a bit vague in keyfeel.

In the end, whether or not this is a viable solution is going to be a personal call. From a functional standpoint, Signature Plastics LP Family 13 keycaps are compatible with kailh low profile switches.

Gerber and QMK code is on github if you want to try it yourself, along with my other boards.

koda has no leds. two extra data pins with GND and VCC were broken out for RGB underlighting. 

diodes were soldered on the underside of the keyboard

ultra-low mill max sockets were used

I had to redo a diode top-side due to the ultra low sockets - taller sockets probably won't have this problem

that's tight! 5mm spacers will do the trick without RGB lighting

socketed pro micro

kailh whites for modifiers, and novelkeys pale blue for alphas

23 mm from top of keycap to bottom of bumper - m2 screws/spacers

kailh low-profile switches with Signature Plastic's LP Family 13 keycaps

At the Atlanta keyboard meetup, someone had brought a PMK grab-bag for rummaging. In this bag was several LP Family 13 keycaps. Much to my surprise, the blank keycaps work on Kailh low-profile switches!

off-centered stems, consistent with Cherry ML

fits on the switch

looks close

Success! Kind of...

I had floated this idea to PMK and Novelkeys before, but the off-center stems were a concern. To investigate, I ordered a varied array of Family 13 (and some defunct Family 11) keycaps. While PMK's website does not advertise these, PMK's parent company Signature Plastics keeps an inventory for commercial customers who use Cherry G84-series keyboards (thanks again, Melissa).

What I found is that with blank Family 13 keycaps, there is a small amount of contact between the switch and keycaps. See the pictures below:

Static

Depressed beyond point of actuation (90%-ish)

Front of the keycap depresses further when forced

So on a heavy bottom-out, the front of the keycap actually travels further down than the rear, as the rear of the keycap contacts the switch housing. However, the travel is within the range of motion for the switch stem, meaning that the keycap stays seated on the switch. There isn't any rubbing, it just feels like there is more give after the rear of the keycap hits the switch housing. This is kinda similar to the interference seen on GMK keycaps on upside-down cherry/clone switches; some notice it, others do not, and for some it's a deal breaker. To investigate it further, I have decided to make a keyboard using these keycaps and will report back.

On the downside, double-shot PMK Family 13 keycaps exhibit detrimental rubbing against the switch housing, and in my mind are incompatible. The fact that PMK utilizes thinner ABS than cherry for their blank ML replacement keys was the key factor for kailh low-profile compatability.

So to sum it up, the only keycaps that work with kailh low-profile switches are:
1) standard kailh keycaps (17.5mm x 18.5mm spacing)
2) PLUM keycaps (standard 19.05mm)
3) Signature Plastic Family 13 - blanks only (18mm) <=== slight rubbing

I'm assuming that the pad-printed Family 13 keycaps would work as well, but I don't have any to verify this. Double-shot ABS is a no go, unfortunately...

More to come...

PLUM ortholinear keyboard redux = endgame

glamour potato shot of the PLUM redux keyboard

I bought a few PLUM keyboards for their keycaps, but their cases were just going to waste. Rather than adding them to a landfill, a replacement PCB was made. Kailh low-profile switches replaced the stock cherry MLs.

split qwerty with numpad center

cherry ML stabilizers

stock cable and LED were repurposed to maintain a sleeper keyboard status

PCB top showing Teensy 2.0 and LED trace

Novelkeys x Kailh Jade low-profile switches

The replacement PCB takes a nearly unusable keyboard and turns it into an ortholinear endgame. The Teensy 2.0 is mounted underneath the PCB for clearance, and the Caps Lock LED is used as both Caps and Num Lock on my custom keymap. The low-profile jade switches from novelkeys are over-the-top in tactility and sound, so they're just right. I am still refining the final keyboard layout, as the form factor has endless possibilities. An extra set of PLUM keycaps is recommended for maximum compatability.

5plit, v2

PLUM keycaps on a 5plit

Version 2 5plit pcb that utilizes PLUM cylindrical keycaps instead of the kailh flat keycaps. The outer pinky fingers were lowered, and the controllers were moved inward in this revision.

left-hand layer

right-hand layer

low-profile for my standing desk at work

While there aren't the best keycaps in the world (laser ABS), I prefer the cylindrical profile over the kailh flat keycaps. I think that the layout is endgame for me, but there is room for refinement.

kailh low profile switches with PLUM keycaps

PLUM ortholinear keyboard

In the search for alternate keycaps for the kailh low-profile switches, I found an interesting post about the PLUM keyboard's keycaps. The centered stems on these keycaps meant that they were compatible with the kailh low profile switches, unlike the keycaps from Cherry G84 series.

PLUM keycaps on a test 5plit board

More to come...

Moth: 31-key keyboard

moth keyboard

This keyboard was my take on a 30%. It was based off the Gherkin, but avoided the unorthodox bottom row with a dedicated spacebar.

pro micro fits nicely

The pro micro is exposed and mounted on top. This keeps the height of the keyboard extremely low. The Moth uses kailh low-profile switches and keycaps, available at Novelkeys.

thin profile - the second pcb was added for rigidity, but isn't unnecessary

This board is a no-go for me. It's not that it didn't work, but the spacebar placement was extremely awkward when using one's thumbs. Three rows is just too short, even for a little travel board...

5plit, v1

36-key split keyboard

The 5plit was an experiment that took advantage of EasyEda's $2 PCB special, and it has become my daily driver. It was designed to be used on workspaces that are level with one's elbows, with relaxed wrists. The keyboard is a single pcb with bottom bumpers and exposed controllers. Function over form, except that the pinky finger is a bit high for this version.

The layout is the same as the minidox, but uses a different pin layout and QMK build.

The switch footprint is 17.5 x 18.5 mm (height x width) for 1u Kailh keycaps from novelkeys, rather than the standard 19.05mm (750 mil) spacing.