Cosmos Keyboards

What is Cosmos Keyboards?

Cosmos Keyboards is a free browser tool that designs curved ergonomic keyboard cases in the Dactyl style and exports them for 3D printing. You build the case by choosing options instead of modeling: keycap profile, switch type, rows and columns, a thumb cluster preset, curvature, tenting and a case mode. Keys can also be dragged and rotated by hand.

The feature that sets it apart is hand fitting. You scan your hand with a camera, the analysis runs on your own device, and Cosmos can then set the key stagger from your finger lengths. The docs call this fitting basic; as of September 2026 it does not place the thumb cluster. The editor also handles trackballs, trackpads, rotary encoders and OLED screens, 15 microcontrollers, and split or unibody builds. A Thickness tab, a part collision check and a small test print catch problems early.

The download gives you STL files for the case, bottom plate and microcontroller holder, STEP files for CAD work and GLB files for renders. Rounded edges, wrist rests and a few other extras marked PRO, such as the Stilts case mode, need a one-time $10 upgrade. It suits people who are happy to solder, wire and flash firmware; with the project's own Lemon controllers, Cosmos can also generate QMK or ZMK firmware for you.

What you can make

• Split ergonomic keyboard cases
• Unibody curved keyboards
• Cases with trackball, trackpad or display mounts
• Bottom plates and microcontroller holders
• Form-fitting wrist rests (Pro)

How to use Cosmos Keyboards

1. Open the generator and pick keycaps, switches and a thumb cluster preset
2. Adjust rows, columns, curvature and case mode, or fit the keys to a hand scan
3. Check the Thickness tab and fix thin spots or warnings
4. Download the STL files, print the Test Print piece first, then slice the case with supports
5. Fit the switches, wire the matrix and flash the firmware