Custom 40% Mechanical Keyboard

This is a Custom Ortho 40% Mechanical Keyboard designed from the ground up to be compact, practical, and DIY-friendly. Built around a hand-soldered Arduino Pro Micro, it’s a minimalist yet powerful little board that fits perfectly into my workflow while showcasing a unique split spacebar layout.

With just 46 keys, it strikes a balance between portability and functionality—ideal for enthusiasts who enjoy the challenge (and satisfaction) of smaller form-factor boards. Whether you’re a seasoned builder or tackling your first custom keyboard, this project keeps things straightforward while still feeling truly custom.

Parts & Components
- 46 keycaps
- 46 switches (3- or 5-pin compatible)
- 46 diodes (1N4148 recommended)
- 2× 2u plate-mount stabilizers
- 6× M2 screws
- Arduino Pro Micro (or compatible)

Printing & Assembly


Inspiration & Resources
This design was shaped by some amazing community resources:

Hackaday: Using a Pro Micro in a Keyboard

Keyboard Layout Editor

KB Firmware Gen