This build guide is for Curve0 v2. If there is a KBD0 logo on the case, your keyboard is v2. What’s New in V2

Curve0 is a stainless steel keyboard that angles the switches instead of the keycaps for a better typing experience. It can be purchased here.

For maximum customizability, Curve0 v2 comes as a kit containing only the essentials:

• Stainless steel case

• Screws, standoffs, washers, wrench

• PCB, daughterboard, and their connecting cable

• 4x small and 4x large adhesive rubber feet (for adjusting the angle to your liking)

You will need to acquire your own:

• MX switches

• PCB-mount stabilizers

• Uniprofile keycaps

• USB-C cable

And you will need some tools to assemble everything:

• Phillips head screwdriver

• Soldering equipment (if you choose the “soldered” PCB option)

• Keycap puller (recommended)

• Switch puller (recommended)

On hotswap vs soldered PCBs

Curve0 v2 can be purchased with either a soldered or hotswap PCB. The difference is explained in the Hotswap Tutorial. This page has instructions for both.

On firmware options

Curve0 v2 supports two firmware options: QMK and Via. Both can be downloaded from the GeekHack post (coming soon). The QMK firmware can also be downloaded from the QMK configurator.

Unsure which to choose?

QMK is more bare-bones; in fact, Via is an extension of QMK that enables remapping on the fly.

The initial flashing process is the same for each but remapping keys is different.

Remapping with QMK requires creating and flashing a new firmware each time. The easiest way is to use QMK Configurator to customize the keymap and download the firmware. If you want to save your keymap in case you want to change something later, you need to download the keymap.json file and hold onto it.

Regardless of which keys you split, if any, you can always use LAYOUT_all and just ignore the extra keys.

Remapping with Via is done on the Via website. If your keyboard is running the Via firmware, the site will detect that you have a Via keyboard and allow you to edit your keymap instantly. Note that at the moment, the files have not been merged into the Via repositories. Until then, in order to edit your keymap on the site, you need to turn on the Design Tab in Settings and upload the provided 75_ansi.json file.

Let's get started!

Step 1: Flash the firmware

This step can be done at any point but if you do it first you can test everything before soldering.

First, download the QMK or Via firmware (see the section above).

Next, connect the daughterboard to the main PCB via the included JST cable. Then, plug your USB-C cable into the daughterboard.

PCB and daughterboard connected by JST cable, USB-C cable connected to daughterboard

The next step is to flash a firmware. To do so, you first need to get the PCB into the bootloader state.

Entering the bootloader

For Curve0, if you haven't flashed a firmware yet, the PCB will enter the bootloader by default when you plug it in to your computer. Otherwise, you can force it to enter the bootloader by holding down the small physical button on the PCB while you plug it in. Once you have QMK/Via flashed, you can also enter the bootloader by holding down the Escape key while you plug in the keyboard. You can also set a custom key combination to enter the bootloader.

You can tell it is in the bootloader if appears as a storage device on your computer.

Flashing the firmware

To flash the firmware, simply copy the .uf2 firmware file onto the device.

Testing the firmware/electronics

Using a continuous piece of metal like a bent paperclip or a pair of tweezers, carefully bridge the two holes of a switch to emulate a key press. Be careful not to short anything else!

Using tweezers to emulate a key press without the switch installed

If the firmware was successfully flashed and the electronics are working, you will see the key pressed on your computer. You can find a free online keyboard tester for to easily test all the keys.

If you are satisfied that the keyboard is working, unplug the JST cable from the main PCB so that it doesn't get in the way of soldering/assembly.

Step 2: Install stabilizers

Install your PCB-mount stabilizers according to the layout you desire.

At most, for the standard layout, you will need stabilizers for backspace, enter, left shift, and spacebar (4x 2u, 1x 6.25u). The soldered PCB supports splitting backspace and left shift if you so desire; if you are splitting a key it does not need a stabilizer.

Stabilizers installed. In this example the backspace will be split, so no stabilizer was installed there

Step 3: Install the PCB

The top case has threaded holes for 25 standoffs. Install them and use the included wrench to make sure that each standoff is snug.

Warning: Do not overtighten! The threads are small and easy to ruin.

Next, put the PCB in place. Each standoff in the case should line up with a corresponding hole in the PCB. All the electrical components should be facing you.

Put a washer on one of the “pan head” screws (the kit contains 27 pan head screws and 9 countersink screws), then screw it into a standoff through a hole in the PCB. Do not tighten it yet.

The reason for not tightening the screw yet is so the PCB can still move around a bit to accommodate the rest of the screws, as it will probably not be in the perfect position right away.

Repeat until all 25 standoffs have a screw and washer in them, then tighten them.

Warning: Be careful that the screwdriver doesn’t slip and damage the PCB.

Warning: Do not overtighten! The washers are small and easy to break.

Step 4: Install the switches

If you have a hotswap PCB

Install all your switches following the instructions in the Hotswap Tutorial.

Next, install your “Left Shift” keycap while supporting the PCB.

This is the only keycap that needs to be installed with the case open. Without supporting it, the PCB will flex too much at the edge and the keycap won’t go all the way on the stabilizer. It is a good idea to install the other stabilized keycaps here as well, as you can better see what’s going on.

If you have a soldered PCB

Insert all the switches into the plate, making sure each switch is in the correct orientation (some need to be upside down) and its legs are straight before pushing it into the plate. Furthermore, it is safer to pinch the tabs with a switch puller while you push the switch into the plate. The Hotswap Tutorial has more detailed instructions.

Now, solder each leg of every switch. Soldering is a topic of its own; if you are not experienced with soldering, you should do some research before proceeding (in particular: through-hole soldering). Thankfully, the soldering in this project is about as easy as it gets.

After soldering, it is a good idea to install at least the keycaps that use stabilizers, as you will be better able to see what is going on. Make sure the keycaps are fully seated on both their switch and their stabilizers.

Step 5: Assemble the keyboard

First, carefully reconnect the daughterboard to the main PCB and screw it into the daughterboard mounting tab using two “pan head” screws and no washers. Again, do not tighten the screws until both are already started in the threads.

Warning: Do not overtighten! The small screws and daughterboard are easy to damage with our big human hands.

Daughterboard connected and screwed in

Put the bottom plate on and screw it in.

Warning: Do not overtighten! The threads are small and easy to ruin.

Finally, install the rest of your keycaps.

Step 6: Put on the rubber feet

Curve0 comes with two sets of rubber feet, four small and four large.

Putting a small foot in each corner results in the keyboard lying flat. In this case, the middle row would be parallel to the table. Since the keyboard is curved, there is no "keyboard angle" like in other keyboards but the closest approximation is probably the tangent to the curve between the home row and the row above it. Using this measure, in the flat configuration, Curve0 has a keyboard angle of approximately 5°.

Adding two large feet to either the front or back corners changes the angle by about 4°. Therefore, adding two large feet to the back results in a keyboard angle of about 9° and adding them to the front results in an angle of about 1°.

Large feet installed on the front corners

Again, the above measures are only approximations and don't even make much sense since each row has a different angle. Instead, your best bet is to ditch any preconceptions about keyboard angle and just see what feels right. Don't rush to commit to an angle as it may take a bit of time for your hands to get used to the curve and start working with it.

Done!

Have fun typing on your new keyboard! I'd love to hear your feedback; if you have any comments or questions, you can join the Discord server or contact me directly at support@kbd0.com