INTROBornheim60 is a 60% layout with arrow cluster and support for small spacebars. The PCB is the BOR60 and planned to come in three variants (solder UNI, hotswap ANSI, hotswap ISO). The case is currently planned to be the HMKB 1A2, which is a minor update to the HMKB 1A1. The HMKB 2 design is in development, but this will take some more time.
PICTURES
WHY?Let me first tell you why I didn't do this layout.
My entrance into the keyboard hobby started way back with the poker III and 60% has been my favorite size ever since. On that poker III you could use caps lock as FN key and map the arrow cluster to the bottom right keys. I got used to this and I still keep using this key configuration to this day on every 60% I build for myself. At first it was strange having the arrow cluster on keys that show a different legend, but it didn't take long to get used to it. I don't question this anymore, it's normal like that for me now. Not having keys with actual arrow legends where the arrow cluster is mapped to was not my motivation to make another 60% with dedicated arrow cluster.
There are two reasons for why I did try a 60% with arrow cluster.
Reason no 1:Over the years there have been a few attempts at 60% with dedicated arrow cluster. Most commonly known is probably the DZ64 PCB. In my opinion, the many 1U keys crammed into the bottom right corner look pretty awkward and the 0.25U shifted R4 isn't great either. I wanted to fit an arrow cluster into the 60% layout and still have it look nice.
Reason no 2:As a 60% user you probably know the situation when friends come over or someone at work comes to your desk and people who have no clue of custom keyboards want to use your computer? They look at the keyboard in a strange and confused way, then start typing carefully with two fingers and when they need to navigate, they look at you even more confused, then it goes like:
But where are the äh, I mean how can I...?OH, you mean the arrow cluster! No problem, it's right there.
Ähm, but it's not?!YES yes, those right there, just press them, see they are actually the arrow keys.
It's awkward. I want to have a 60% where this situation can be avoided and people who have nothing to do with custom keyboards can use the board without or less hesitation.
STAGGEREDCan I say "staggeredness"? That's one thing I like about keyboard layouts. Sometimes I just stare at the keys of my keyboard and it has some kind of hypnotizing feel to it. However the spell breaks as soon as my eyes get caught on any spot where key corners meet in a non-staggered way. You know the spot where `>`, `?` and the 1.25U keys below meet on the 60% layout with 6.25U spacebar? Uh, I don't like that. That's just one reason why I prefer classic bottom rows with 1.5U and 1U keys as modifiers. Staying staggered as much as possible was a design goal I had.
And it worked out! No matter what bottom row option you choose, it will always be all staggered. No weirdo 1.25U modifiers in the bottom row, strictly classic 1.5 and 1U. Of course, that may or may not be something you like.
Key layouts and options of hotswap ANSI and ISO as well as solder unified:
ArrowClusterYes, even the arrow cluster is staggered. If it wouldn't, it would somewhat break the whole layout. It also works well from an ergonomics perspective. Your three middle fingers fit more naturally on the cluster this way and the middle finger moving up and down works nicer this way too.
SmallBarsSupport for small spacebars wasn't on my mind when I started this. However, the missing modifiers can be a disqualifying factor for many, and smaller spacebars make room for those modifiers again. With small spacebars there is even room for a fourth modifier on the left side. Typically, you find four keys to the left side of the spacebar on notebook keyboards. This option might make switching between notebook and desktop more seamless since you can duplicate your notebooks' key layout.
CHICKEN & EGGSmall spacebars? Support for those isn't widely available and 5U doesn't exist at all!If no one ever comes up with a layout/pcb that enables small spacebars because not many keycap sets support them or that particular size doesn't even exist, then there is also no incentive for keycap designers to add more small spacebars to their sets, let alone make new molds for not yet existing sizes. That's the chicken and egg problem, one must come first.
To be fair 3U is already widely available in key sets. It is usually adopted in 40% layouts but rarely seen in bigger layouts. Then there is also 4U existing in the MT3 profile, as you can see in the pictures. I'm not aware of any other profile offering a 4U. I think there was a 4.5U GMK spacebars introduced recently. The BH60 solder PCB does support 4.5U but only with MX standard stem positioning and I don't know if the stem positioning of the GMK 4.5U does stick to the standard. 5U - I haven't seen that in any keycap set yet.
Bornheim60 would invite keycap designers to offer a 4U spacebar like MT3. It would be the egg to a 5U spacebar - or would it be the chicken?
WIRESBut stab wires! Yes, I hear you, absolutely right you are! Stab wires for those small spacebar sizes are hard to find. Even 6U is rare. While you can bend them yourself, it is quite tricky and if you don't get it right perfectly, you end up with a botched spacebar experience.
I already reached out for a solution. If this ever gets to group buy, then I will offer stainless steel precision bent stab wires in 3U, 4U, 4.5U (maybe), 5U and 6U, made in Germany.
PCBIt's designed by Ebastler and I'm super happy he was available for this project. The PCB is called the BOR60. BOR is short for "Bornheim", which is the name of the key layout. If you are aware of any PCB existing with the name BOR60 - please let me know, then I will rename it to something like BO60, BH60 or something similar.
The PCB will come in three variants. Solder, hotswap ANSI and hotswap ISO. ANSI and ISO can be combined in one hotswap PCB but this would mean that some keys are rotated by 90 degree. This can lead to key cap stems cracking. That's why the hotswap variant will have a separate PCB for ANSI and ISO. The current protos have the USB connector protrude from the PCB. This fits well with the HMKB 1 case. However, it can be broken off and used with a daughter board instead. I'm working on a new case design that will require the daughter board and by supporting both, the PCB will work with both HMKB 1 and later HMKB 2. For those who don't like the new and tiny connectors for the daughter boards, through holes are present. Those allow you to solder a daughter board with normal wires directly to the PCB. It's basically a fallback feature in case the connector breaks.
Despite the many spacebar options, the PCB has a very clean bottom row that doesn't look like swiss cheese.
Here are pictures of the hotswap ANSI, hotswap ISO and the solder UNI:
The prototype PCBs have silver pads, production will be industry standard gold.
Specs- 1.6 mm standard thickness
- all switches north facing (except some hotswap options)
- no flex cuts
- no RGB LEDs (no underglow, no in switch)
- onboard USB-C connector (breakable) and daughter board connector
- MCU: STM32G431
- QMK Firmware with native VIA support
- three variants (solder UNI, hotswap ANSI, hotswap ISO)
HMKB 1A2The current plan is to offer this layout with the known HMKB case design. A new design is in development, but this will take more time. HMKB 1A2 will have slight modifications over 1A1. The plates mount holes will be the exact same, so plates will be interchangeable between 1A1 and 1A2.
The HMKB 1 is a full steel, enclosure made from sheet metal. Combining steel and the manufacturing method of precision bending results in a heavy and rigid construction. The bolts piercing through the frame reveal the classic top mount design.
Through hole TPU grommets fully isolate the plate from the case. The wide body of the case allows the plates to be bigger than usual. This way the plate gains more mass which effects sound and typing feel. The TPU through hole grommets are also used to separate the top from the bottom case shell and those same grommets also function as feet.
The overlapping and open flanges are a deliberate choice and emphasize the sheet metal bending technique. The typing angle can be adjusted by a screw-in mono-foot, which keeps the case resting solid at every angle. When extended, the black mono-foot disappears in the shadow and makes the case appear like its rear is floating.
It is a minimalist design without any branding, made in Germany.
Specs- full steel construction
- top mount construction
- plate fully isolated (TPU grommets)
- high profile case, caps sink in deep
- adjustable typing angle (6, 8, 10 and 12 degree) via...
- screw attached mono foot
- low first/lowest key row
- 3.5 mm EPDM plate foam (more foam options in testing)
- weight of complete build ~1.45 kg
PLATES- FR4, simple black
- POM (will show prototypes later)
- CF with serpentine cuts (still prototyping)
- Full mass brass or inox plate (to be decided)
Here are some current plate prototypes:
![](https://cdn.discordapp.com/attachments/1178677375999934516/1178686991081144320/hmkb-bor60_plt-cf_02b.webp?)
Still prototyping more plate options. Pictures will be shared at a later time in the thread.
FOAMSStill in the works. I'm trying different configurations. I'll post more regarding this in the thread once I have more to show for.
COLORSHMKB 1A1 came in beige, yellow, gray, black and a stainless-steel variants. For the prototypes of HMKB 1A2, the same beige, yellow and black are back again and I tested a few more RAL colors. I don't intend to offer all of them. Depending on your feedback it will boil down to three or four colors. The ones you see in the photos are:
- RAL 1013 Perlweiß (Oyster white), RGB: 227, 217, 198
- RAL 1023 Verkehrsgelb (Traffic yellow), RGB: 247, 181, 0
- RAL 5018 Türkisblau (Turquoise blue), RGB: 5, 139, 140
- RAL 5022 Nachtblau (Night blue), RGB: 34, 45, 90
- RAL 7011 Eisengrau (Iron gray), RGB: 82, 89, 93
- RAL 7038 Achatgrau (Agate gray), RGB: 176, 176, 169
- RAL 9005 Tiefschwarz (Jet black), RGB: 14, 14, 16
- RAL 9016 Verkehrsweiß (Traffic white), RGB: 241, 240, 234
For those who don't know, this is all powder coating, all Feinstruktur (fine texture). Powder coating is applied in a multi-step process, is very durable and not to be confused with paint. For example, paint can chip off whereas powder coating is fused to the metal. Powder coating is usually available in glossy, semi-glossy, fine texture and rough texture. I prefer fine texture.
I tried to find RAL colors that are a nice match for some popular sets or can be paired with common keyset colors.
Stainless steel will not be a thing again. This led to too much b-stock. By the way, I still have lots of those HMKB 1A1 stainless steel (inox) b-stock cases. Not directly available in the store though, if you are interested, use the contact form on the store page.
BIGGEROf course, arrowCluster in the alphanumerical block and smallBars don't just work in 60%. F-row could be added, which would result in a 70%. Num-block with or without F-row is also possible. Here are simple mockups of what might be:
![](https://cdn.discordapp.com/attachments/1178677375999934516/1178687413401436210/HMKB1A2_bornheim-bigger-95.webp?)
However, the next group buy would only cover 60%. For now, the bigger sizes are only something that might potentially happen after 60% is done.
No like arrowCluster?It's hard to predict if there will be enough people liking the arrow cluster design. It may turn out that more are interested in just having small spacebars in a more standard 60% layout. While I plan to offer the Bornheim60 even if the interest is low, it would mean that a second branch will have to be offered alongside to get a sufficient number of participants on board. This backup plan would add a 60% layout called "SmallBars60". Here is the layout with its options:
![](https://cdn.discordapp.com/attachments/1178677375999934516/1178687730725703761/2023-11-21_SB60-SD-UNI.png?)
SmallBars60 is more standard conform. The spacebars would not range from 3U-6U but instead from 4U-7U. This way the layout would also cover tsangan builds. Even a true HHKB (6U) is supported. Just as the Bornheim60, it could grow bigger to 70% with F-row and 90% with num-block.
If it turns out the additional PCB series isn't necessary to be offered alongside, I do plan to offer the standard case variant (no blocker), WKL and HHKB at the same time anyway. There are plenty of other PCB options out there that can be paired.
PRICINGThe pricing is not yet determined. I'm trying to offer it at an "affordable" level.
FEEDBACKIf you are interested in this project, then I hope to get some feedback from you. There are some aspects that are of particular interest for me:
- what do you think about the arrow cluster?
- what do you think about the small spacebars?
- are you more interested in the small spacebars but less in the arrow cluster?
- what do you think about the bigger sizes?
- what about HMKB 1A2 and the colors?
- what plate options do you wish for?
INTERESTED?If you are, please fill out the IC form:
IC FORM LINKHMKB DISCORDHEAVYMETAL KEYBOARDS---
Please excuse that I probably won't update this start post. Additional information, changes and updates will only appear in new posts throughout this thread.