We Made a One-Handed Keyboard

Last winter, a father wrote to us. His daughter lost her right hand's function after a truck accident. When using a computer, she had to switch constantly between the keyboard and mouse. Typing was slow and tiring. He wanted us to build a one-handed keyboard for her and attached a hand-drawn sketch. After the email, we called them to discuss their needs. They wanted a keyboard fully covered by one hand with a built-in mouse. We checked existing ones. Most were for gaming, few keys, no typing. Others required memorizing tricky key combos or layers. The closest match was a keyboard from an Austrian company, but it wasn't QWERTY and cost 990 euros. Can we build a keyboard that perfectly fits their needs? Let's start. Here's our keyboard to fit all keys under one hand. We used the compact 61-key QWERTY layout in a fan shape. We used the smaller Elbs yellow switches, but they felt stiff, so we looped every one of them. For key placement, the original spacebar made the thumbs stretch. The delete key was too far. We moved both to right corner for easier access. For the mouse input, after comparing the trackpoint, trackball, joystick, and touchpad, we chose the trackball as it offers the best balance between precision and compact size. Existing trackballs were too bulky, so we tested the materials until finding the one with the right weight and grip. Users can scroll the trackball with their thumb and click mouse buttons with their fingers. We embedded six tiny balls in it for smooth rolling. A magnetic cable was added for easier one-handed plug-in. Typing looked like this. This looks done, but it's actually version 7. Early versions ruled out wrong ideas, like using the entire keyboard as a mouse. Version 3 worked, but had awkward angles and poor scroll wheel. Version 4 fixed these. Version 5 improved the case and replaced mouse switches. We sent it to the user for feedback. They loved it, but noted issues like small keys easy to mispress and unstable magnetic cable. We refined the design further and slimmed it down. After learning that the user liked colorful designs, we designed several color options for them to choose from, and ultimately made this special macaron-themed version. But this also had mispressed wrist and discomfort for larger hand, so we made a plus version. The plus uses center-sized mechanical switches, fewer typos. Its larger size allowed adding LEDs and sound damping features. Perform phone between the plate and the case, plus padding under the PCB. Typing sounds like this. Everything's ready, we sent both keyboards to them. The keyboard feels like it meets our needs. If you have any questions while using it, feel free to tell me in the comments. We'll try to optimize it until the keyboard meets your needs. Since we already made it, why not make more? We designed the plus keyboard for the right hand and built 50 sets, 25 for the left hand and 25 for the right. We've already donated the keyboards to the people who need them. We also open-sourced these keyboards, hoping to help more people. Thanks for watching, see you next time.