a low effort half plate flex cut 60% using readily available parts

[vidas]

Hello, this is my first post.
Everyone I talk to about keyboards has been deep in the flex meme for at least 6 months now and in order to find out if I even like a flexible keyboard it would have required joining a group buy and waiting forever or going to a marketplace and spending legitimately all of my money. My goal is to post what I did in the event anyone else finds themselves in a similar situation. Half documentation of my project and half guide. I'm going to post what I did and then a log of my build to document my ridiculous mistakes for the worl to see.
I wasn't willing to do a gb or aftermarket buy because it's counter intuitive that a flexible keyboard for linears could be desirable. In laptops a flexible keyboard is a cardinal sin.
So using open source projects, off the shelf parts, and some free personal use fusion360 I was able to make one for under $200. $40-50 of which was wasted. Should be cheaper for anyone else that tries. I'm not offering support just a description of what I did. Plenty of smart people on the various websites and chat rooms that can help you with soldering or whatever.

Typing test:

Flexibility:

Seeing Maarten Dekkers open source PCB the plain60-flex, sick pcb btw you're the best, was universal 60(pok3r etc) compatible I realized that to get a flexible board all I would need is a tray mount case with no stand offs beneath the letters. I have been borderline obsessed with getting the most out of the plain60flexes because I love open source hardware and I think it can solve a ton of the problems you often hear people complain about regarding MK markets and prices and stuff.

The PCB
I used JLCPCB's SMT assembly service along with some help from Xyz on discord(project would have never happened with out him idk if hes on gh) to get the PCBs made as maarten didnt have any for sale. If he does when you read this then just buy them from him it is far easier that way. I had to buy and solder on the USB port and resonator myself.
You need the following files during the ordering process:
The open source gerbers you can get from here https://github.com/Maartenwut/plain60-flex-edition
and a BOM+CPL which I've uploaded here
https://drive.google.com/file/d/1rVirTMZQYan6xHKtDA6p4Ui_p9wTdVtk/view?usp=sharing
https://drive.google.com/file/d/1MbwlU8oNzIF9OlaOeRIAIsl6Yn56yiJD/view?usp=sharing
You upload the gerbers from Mr. Dekkers to https://jlcpcb.com/ , select green for the pcb color, and either 1.2mm or 1.6mm depending on how flexible you want it to be. I did 1.2mm. When doing SMT assembly you need to buy 5 PCBs and have either none, all 5, or 2 built. I went with 5 as swapping the PCB/plate assembly is far faster than hotswaping.  Then it will ask you for the BOM and CPL files above.

again you need to buy the USB ports and resonators. They are here.
https://lcsc.com/product-detail/USB-Type-C_Korean-Hroparts-Elec-TYPE-C-31-M-12_C165948.html
https://lcsc.com/product-detail/Others_Murata-Electronics-CSTNE16M0V530000R0_C341521.html

You need flux to get them on, I used "MG Chemicals 8341 No Clean Flux Paste" it has prime shipping. This was the instructional video I used to learn how to get them on with my cheapo weller iron. Ignore the part about the wick as you're not replacing but installing one. Maybe there are better ways to do it, I don't know. I'm surprised mine even works.

These dont have ports and resonators yet, only the one I installed did, but this is what you get from JLC. oh also the resonators are obscenely tiny you will need like esd tweezers or possibly some form of strange mutated tweezer sized fingers.


after typing all of this up i learned that novelkeys is selling a 60% flex cut pcb. it's almost the same price as 5 of the plain60s cost me but it is easier i guess.

The Case
This is the easiest part. I typed in "60 keyboard case" on aliexpress and the first result was a $50 tray mount but that had the stand offs only around the perimeter of the case. kinda like how TGR unikorn does but roughly one one millionth as nice looking.
It's here https://www.aliexpress.com/item/32921993410.html
and this is what it looks like


The half plate
Since I could not find a public 60% half plate I made one in fusion360. It is NOT PERFECT. I probably removed too much material. People have said the switch cut outs aren't very good. People have said that the space bar section of the plate should have flex cuts itself(I disagree, the whole point of half plate is to have a solid space bar yet flexible letters). That being said it WORKS.
Here is the DXF file https://drive.google.com/file/d/1IL-HKtOwg6xQTwTw8ihCOgXvR4K0Em0r/view?usp=sharing
There may be a cheaper way to get them but what I did was go to sendcutsend.com and uploaded the file. I select aluminum 6061(it needs to support two flexcuts on a thin pcb so i wanted strong metal but aluminum sound) and 1.6mm or maybe bit was 1.5mm. You'll see it.
You can see a lot of the plate given the low profile nature of the case. It is UGLY. To make it slightly less ugly maybe brass would be a better option. It's more expensive and I never tried it though.

The rest and the gummy worm
So I actually managed to "gummy worm" the board. I didn't think it would work and it is a very tight fit. I bought the huge oring the TGR Unikorn uses and put it around the plate and pcb the same way. Because I used PCB mount screws in the rubber bulges out a lot around them and so I used one of my ESD tweezers to carefully crush the rubber down into the case. Its not perfect but it actually works some how. The entire pcb/plate assembly it'self goes up and down a little bit because it is resting on rubber and the usb port still ines up with the cut out. This part is optional and was not even the original plan. My only goal was a half plate flexible board. nothing else. Here are the orings. Sorry I bought 8 which was all they had apparently but maybe they'll restock by the time you read this. https://www.theoringstore.com/store/index.php?main_page=product_info&products_id=766
If you use PCB snap ins it might work much better and easier to install and take out. Sadly novelkeys didnt have any last night when i ordered two more plates to do more builds. My buddy Tenturo told me you can file down the pcb screw ins and make it fit better too but i don't know anything about that.
of course you need switches and stabs and a cable.

Different approaches
I edited this post to add this.
It is also worth mentioning that you can do this with nicer cases. The one I used is admittedly hideous.
There are a lot of options but they all involve a dremel.
You can take any normal universal 60% case and simply dremel off the center and space bar stand offs and theoretically use the same plate and pcb to achieve the same thing in a nicer case. Before I found the case that I used this was the plan. I was going to use that cheap $11 gh60 plastic case you see absolutely everywhere. But it and a dremel cost more than my aluminum case did.
I am saying this based on the assumption that my case and all of the other universal 60% cases have the same height stand offs. If the stand offs in the tofu, fjell, 5 degree, etc are shorter than it will not work and your pcb will slam into the bottom of the case. In that situation you could perhaps use a 1.6mm pcb to reduce the flex and hopefully avoid that. If you instead try to raise the stand offs with spacers then your usb port will not line up. To get around that you could perhaps hard wire a usb cable on and run it through the usb cut out instead.

Another approach that has already been done is to take a integrated plate universal 60% case and dremel it into a half plate and then use these same PCBs. It was done already here

The HHKB integrated plate tofu has been out of stock for a long time now buuuut krepublic has something similar https://kprepublic.com/collections/case/products/xd60-xd64-xiudi-60-aluminum-case-with-acrylic-diffuser
If you were to cut that case into a half plate the result would be much nicer than mine.

That's it. I will reply to this post with my little after-the-fact build log. This all ended up not being quite so easy as it seems on paper. I bought two plates of an earlier version of that file that don't work, killed one and 1/20th PCBs, and mutilated four switches.

[vidas]

Build log
I first needed to figure out how to get the PCBs as I wasn't going to solder on every single part. I spent hours messing around with this script that was supposed to generate the files needed to place the order but it just did not want to work. I woke up the next day and had a message from xyz with the needed files.
For the plate my friend made a version from the same original pok3r file. I looked it at it thought it looked good and ordered two.
I was worried through all of this because I wasn't ever sure that the case had enough space below the stand offs for the PCB to flex without slamming into the bottom of the case which would have felt and sounded horrible.
The PCBs finally got here and there was enough room in the case.
While waiting on the resonators and usb ports which were coming from china I decided to build a board just to type on it without it being plugged in and install them later.
For the switches I had 50 nk dry and 50 nk silk yellows. I lubed all 50 of the dries with 205 nlgi 0 and then 15 of the silks, using tx films and sprit 68g slows.

Attempt 1
So I set up my iron and everything and then started soldering. First I soldered in all the plate mount switches with their PCB mount legs still on.
The pcb had pcb mount holes for every switch so I thought it wouldn't be a problem.
It was a problem. There was no way to get the plate on level.
So then I started desoldering them. I was not aware that the ss02 required extensive cleaning and lubing to continue working well. None of the joints came off cleanly, I had to keep adding solder and sucking again. I pop blood rage and lifted countless pads and just straight up mutilated some of the switch positions as at that point the only thing I wanted was to get my switches out and start over on a new PCB.
NSFL printed circuit board abuse follows:




okay I finally get all of the switches out. I killed the pale blue I use for enter because it had THE WHOLE OF A FRONT PAD stuck on a leg. And a couple of the lubed linears through various means.
Later that night I learn that all I had to do was lube the solder sucker. Regardless a chinese hako desoldering gun is quickly becoming a priority. I say to myself that I'm no longer going to put myself into a position that I have to desolder until I can get one.

Finally the switches are free. I decide to just use stock silks on the unimportant keys I never use anyway as I do not want to start lubing new ones to replace the dead ones.
I cut the pcb mount legs off and solder in the plate mounted ones again. Everything is going well, finally I'm going to get to type on this thing.
Then I get to the first PCB mount switch.


They don't fit. I feel utterly defeated.
When the person made the plate file they just removed the area starting from the top of the switch cut out. They didn't remove any extra area so the switches that flex can clear the plate.
So not only did I buy two plates that won't work but now I have to make a new file, i had never even used cad software at this point, and worst of all I will have to desolder again.

Attempt 2
It took me a few nights as I had no reference for how these half plates are typically done. I find a Bliss TKL half plate file and see that it leaves 4.55mm of material between the plate mounted switches and where the pcb starts. I think the minimum was 4.6 and so sendcutsend would have to get it with in .05mm for that to work. To be perfectly safe I decided to do 2mm.
For comparison the original failed plates had 5mm of material. Send the file into sendcutsend, costs me $30 since the needed accuracy was higher, and wait a week.
It gets here last night. Following is the new plate directly ontop of the old so you can see how much material needed to be removed for it to work.


I go to desolder again having lubed and cleaned my ss02 and manage to only kill one switch. The plate works it's the right size. Spend a half hour trying to find my little baggy of stab parts as the previous plate didn't have right shift and this one does. Get it on.

SMT soldering for room temp iq keyborbist
Deciding that I really don't want to kill one of the 4 remaining PCBs(I basically do anyway) I try and do the USB port and resonator on the original mutilated PCB. Do exactly as it shows in the video above and all looks good. Go over to the computer and try and plug it in and see if it works.
It's not working.
Unplug and replug it, look in device manager to see if anything at all is popping up. Nothing is. I flip over the PCB to see if anything is smoldering.
As I flip it over the entire USB socket rips off of the pcb. I forgot to solder down it's support legs.
I also didn't know that I had to hit the two pads with a ESD tweezer, like how you turn on a desktop when it doesn't have a power button, for it to show up.
Okay well the next best thing is to try on the PCB i have the switches in. I get the port and resonator on. Plug it in, hit the pads, nothing. Try a different USB port(i know the port it was in worked and still does) and it shows up in the computer. Flash on the VIA compatible hex file and proceed to try all the switch spots to see if everything works.
Escape, left tab, left shift, and 1 all do not respond. They also do not respond if I try to jump the pads.
Okay, whatever, I'll figure it out later.

Soldering in the switches
I take it back over to my little soldering set up and solder everything in. I had to stop after doing 4 switches and desolder again as one of the solder blobs on the usb port was too tall and wouldn't let the plate sit level. I get those switches out without problem. Solder everything in and it all seems to go fine. I look at the back where the usb port as that is where all the switches that do not work sit. I can't see anything wrong at all. Even now I do not know why they do not work. I'm going to look at it again tomorrow.


The final mistake
Vert excited to finally type on the thing after being on my feet for 7 hours at work and another 9 when I got home. Thinking that the oring wont even work I try it anyway. It is a VERY tight fit because the stabs are pcb screw ins and so it bulges around them. I managed to get it to fit by going around the whole perimeter with a spludger and pushing the band in.
I take the GMK red samurai set off my coolermaster pbt s with black inks and put it on the board. Then I get to the space bar.
It won't sit level.
I hate myself.
I look at the stab closely. The left side slider is mutilated.
It looks like that slot on the space bar warped from being squeezed onto a costar stab+cling wrap. As you know costar doesnt fit into gmk so you have to put a piece of wrap over it and press the cap down on top of it.
I take some flush cuters and try to clean it up. It's still not perfect but at least I can get the bar down onto it.
At this point it's done.


It's a very very good board and easily the best typing experience out of my pile of like 13 or 14 keyboards and it means the most to me as it took, by far, the most amount of effort. At the same time I'm very disappointed that important keys do not work and the space bar isn't perfect. So last night as soon as I finished I ordered two more plates. Over my next three days off I'll lube up two more sets of switches and solder together two more PCBs using PCB snap in stabilizers and they will be the ones I use going forward having learned from all these mistakes. If you make one be very careful at each step and don't just do one pcb if you've never done something like this before. I have soldered and desoldered easily 1500 switches at this point and I still made tons of mistakes.
For the two PCB/plate combos I'm thinking about doing one with PTFE powder lubed novelkeys creams as I've never used creams before yet have them sitting in my switch collection and for the other one I'm going to do everglide bottom, cherry silent stem, gateron ink top housing with gpl105.

Thanks I hope this was at the very least entertaining.

[Datastream]

Man what a journey. Congrats!

[Lysol_]

congrats on finally finishing this.

[Tenturo]

The amount of effort put into this is daunting, and I commend you for that. Grats on the finished project!

[vidas]

Thanks guys. The soldering at the end was a nightmare because I was behaving as if my ss02 would work the same way it did when it was new and it just doesn't. Even after a lot of cleaning and lubing it just can't clear solder joints as well as it used to.
Tonight I took a look at it to see if I could get the 1, tab, escape, and left shift working as it was unusable with out them.
It turned out that I forgot to solder in the 1 key completely, so that was a quick fix. Then I moved onto try to fix the tab key and so I jumped it to the enter key and for some reason after doing that all of the other keys that were not working started to work. So now all of the keys work.


I just found some domestic stock of PCB clip in stabilizers so I ordered three sets and I've also ordered two more of my half plates. This will be enough to do two more builds. It takes like twenty seconds to change out the pcb/plate in the board with a new one so you can swap between switches very quickly.
Additionally I found another case with the same properties as this one in that all of it's stand offs are around the perimeter of the case. It should work the same way my metal one did. It's here https://www.aliexpress.com/item/32961827631.html When I have some more money saved up I will try it out.
 

[treeleaf64]

yes Vidas my boy thank you

[stotle.caps]

hello,im interested in this project,how many resonators do you need,and if you can pls add it to the BOM and CPL files,im kinda confuse,and the diodes are on an inventory shortage on jlcpcb side,can any alternative to it?

[chungsteroonie]

I'm in the same boat. . . For the diode, I've substituted 1N4148WS which has skinnier legs than the one originally specified, but it should fit inside the footprint. 

I am having another issue though.  I cannot open the Kicad files provided in the repository with latest version of Kicad (my only version of kicad).  It looks like JLCPCB is now able to install the USB C port, and I'm trying to get the relevant information for part designation, X-Y coordinates, and orientation so I can update the BOM and CSV files.  I would also like to open the Kicad project for educational purposes as this is the first time I'm looking at a PCB. 


Any help would be appreciated.