The Concordia - A new keyboard design where symmetry prevails

[Rico]

Hello keeb lovers,

In December 2025 I finished The Aquanaut, a two keyboards project (one Cherry MX and the other Topre), and I love typing on both of them!
So why doing yet another keyboard project?
Well I have two (related) issues.

Issue No 1:
I did not realized how much I missed Topre tactility until typing on the Aquanaut EC version, I want moar

Issue No 2:
I bought three URSA Topre keycap sets designed by @Andreas, URSA is simply the best spherical keycap profile (at least for me) I typed on.
But I used only the WOB set, the Classic and Minicom sets are still staying in their boxes waiting to be put to good use.
This is unfair and this problem need to be addressed.

So here I am with a new keyboard project, to be able to use one of my two URSA sets and have a Topre board at home (my Aquanaut EC is on my work desk).
This will be a single board project this time.

Concordia is the Roman goddess of Peace, Concord and Harmonia (that is also the name of the Greek counterpart).
In the ancient Greece harmonia was often heavily related to symmetry, and this is most of what this keyboard is about.

Like the Aquanaut this is a numpad southpaw board but this time the numpad has been amputated of it’s right most column to be 3 columns wide, just like the navigation cluster.
To increase the amount of symmetry the layout uses an F13 and a 7U spacebar bottom row (not seen in the KLE shot).

I thought of doing totally similar left and right key clusters but the URSA keycap sets have no enough keys to populate this, maybe for a future project ?
The layout shown below needs only the keys of a standard URSA keycap set with the addition of either an accent kit or an artisan cap.

Here is the KLE view below (with a 6.25U spacebar, oups…)!

More to come (very) soon

[Rico]

There is a lot to show in the design decisions I made, too much for a single post that would be otherwise be too long to read, so let’s do things step by step.

Here is the what I decided for the plate and mounting method, first with a shot of the plate itself.

No complicated leaf spring mounting system this time; I decided to use a simple silicon dampener mounting system where the dampener is sandwiched between the top and bottom plate.

The silicone dampeners used are standard ones used routinely on drones and widely available for cheap and in various colors on many vendor sites.

I used the M2 screw variants, although no screws are used for the mounting system because I wanted the plate to be totally isolated from the top and bottom part of the case.

Here is a closeup of one of the dampeners installed:

There is a little bit of a twist here though, as you can see the mounting posts are quite large.

On the right side of the post there is the option to add a small Poron pad between the plate and the bottom part of the case to eliminate all trampoline effect (the silicon dampeners are quite soft) and vibrations.

The left side will be in contact with a small pole in the bottom part of the case when 1mm compression is reached, this is to limit the amount of compression distance of the plate and 1mm during typing is more than enough.

If you look at the switches cutouts they do not look exactly like standard Topre cutouts, this is because I decided to use Dynacap housings for the build; this will make the plate 1.5mm thick (and in stainless steel of course).

This will be an hybrid of Dynacap housings (purchased at Omnitype) and OEM sliders (purchased at Unreal keyboards because I did not want to buy and salvage another Realforce board).

This hybrid approach looks to works but not without a bit of fiddling and thinking, this is definitely not something I’d recommend a beginner to try for it’s first EC build

I may give more details later when I’ll actually build the board.

See you later for details on the case itself

[Rico]

At first I wanted to talk about the main PCB but in fact I don’t have much information to give and will not post pictures of it because it is not worth it.

This has been a lazy design were I took the Aquanaut EC PCB as a base (because it proved to work very well) and removed one column (the one with the numpad plus and enter keys) and that’s pretty much it.

Still I made a change to adapt a custom made daughterboard PCB, this one will be much more interesting to talk about later in this post

So let’s talk about the case!

I am a sucker for big bezels but still like the harmonious Korean proportions.

So this time, at least from the top view, you’ll see a keyboard that is very Korean alike; this means 1/2U top/bottom and 1/4U left/right bezel sizes.

Even from a top isometric view it looks strangely like a GeonWorks F1-8X V2.

From the side this is a box and wedge design but you can see a strange protuberance on the back of the board.

Here is the back view for a better view.

And back isometric views for better shape understanding.

The back shows the weight, the feets, and how the board is assembled.

No complex hidden screw design (still you see nothing when the board in on the desk), simple 7mm adhesive round silicon feets.

The brass weight has a simple symmetry symbol engraved on it.

Here is a general view of the bottom piece:

There is a hole on the back where the daughterboard will sit but no screw holes to fix it, strange isn’t it? We’ll come to this detail later.

Most of the alpha and nav clusters have cavities underside them that are 2mm deep.

Under those cavities the distance to the PCB is 4.5mm (2.5mm outside the cavities), this is to give ample space for air to travel and have bassier sound (the ‘thock’ factor that EC people love :p).

This is a mimick of what you can see in those plastic Realforce keyboards that have a lot of room between the PCB and the bottom of the case.

The front and back parts are quite busy, here is a closeup view below.

There are rails to place 3mm Viton (or silicon) Orings that will be in direct contact with the top piece; this is the same general principle as in the F1-8X (or the Aquanaut) but this time the plate is not sandwiched between the Orings.

The goal is to prevent the top piece to ring like a triangle instrument when typing, this is technically a force break technique even if the goal here is not to prevent the top piece to make contact with the bottom piece: the viton Orings are here to absorb all the top piece (and a little bit of the bottom piece) vibrations.

You can see the pole to limit plate travel to 1mm on the left of the mounting pad and the 3mm Poron pad(optional) on the right of the pad.

The daughterboard PCB is quite special.

It is not fixed to the bottom piece but to the main PCB itself with the help of PCB standoffs and screws and make electrical contact with the help of pogo pins.

This allows the USB connector to sit low in the case and facilitates disassembly/reassembly: I came to hate JST cables with a passion

The problem with USB connectors on the main board is the dilemna associated with it as you need empty space around the connector to allow the PCB to flex or tilt without the connector to make contact to the case (and potentially break).

Too little of a space and your USB connector can easily touch the case (but it is darn pretty) or big space and it looks ugly.

The solution has been to create a USB cover that is fixed to the daughterboard, the best of both worlds (well I hope).

This piece will be 3D printed in aluminium.

Here is a look at the daugtherboard with the cover placed in the bottom piece, this is difficult to see but there is a gap between the back of the USB cover and the pottom piece so that everything can move without any contact.

The board is not a chonker given it’s size, weighting only a little over 2KG with case, weight and plate, but I hope the sound will still be good.

Other dimensions are:

• 7 degree typing angle.
• Front height is 17.5mm.
• Adjusted front height is 18.5mm.
• Adjusted front height with feets is 19.5mm.

The whole board design is mostly complete and in carefull review phase before going to manufacture.

I hope to send the design to manufacture by September.

See you later!