trackball VS tractyl-manuform-keyboard

I did lay out a simple carrier board as a direct replacement for the breadboard in a more permanent build, and had a few of them made up through OshPark. It's really basic -- no components, just some traces and solder pads. (My first time trying to use kicad, I think it turned out decent for what it is.)

not quite sure what you are getting at... regarding thumb use, you can always buy used FXes (or new ones if you want a crazy markup). if you want something slightly more modern, there is the cordless FX. the DIY trackball you speak of is publicly available here: https://github.com/monroewilliams/trackball

isnt a scan, but its a 3d printable trackball with roughly similar shape: https://github.com/monroewilliams/trackball

For me, the hand position used with the Logitech Trackman Marble FX was near perfect for reducing hand and wrist stress. Unfortunately that model was discontinued many years ago, and they're now hard to find, expensive, and generally antiquated (PS/2 interface, dodgy early optical sensor, no scroll wheel). This was the main reason I designed and built my own trackball. Its shape was inspired by the Marble FX, although I modeled it from scratch in OpenSCAD.

Of course. 😎

Sources for all the parts I used are listed here, and there's a fairly extensive assembly guide with pictures here.

For my scratch-built trackball project, I used these breakout boards, and based my initial code off of the seller's sample code. His sample is for Arduino. but it's basically pretty straightforward C code that isn't hard to adapt to any microcontroller. For my purposes I needed to run two of the sensors off one microcontroller, so I turned into a C++ class that runs one sensor per instance, and supports a couple different related sensors (ADNS9800 and PMW3360).

The ball-spin mousewheel is a really nice touch, too

This keyboard is an attempt to make a best-of-both-worlds combination between the modular (and support-saving) design of dereknheiley's compactyl manuform (with adjustable wrist rest mounts) and the trackball-enabled design of the noahprince22's tracktyl manuform, forking the firmware from Schievel1's dactyl_manuform_r_track.

https://github.com/noahprince22/tractyl-manuform-keyboard There are links for everything here, but if you plan to make it wireless I think there are other sensors which consume less battery power

The tractyl manuform from noahprince22 outputs a model with a test hand with the finger length input from base to knuckle to knuckle to tip. I've found it gives a pretty decent first impression of the alignment of the dactyl in your hand. To get it just you do need some iterations with a test model

https://github.com/noahprince22/tractyl-manuform-keyboard this one does, its quite different from a lot of other manuforms, so it might be worth just using the code that generates the slots for the daily sockets and adding to a variant you like

Tractyl Manuform

So, I followed this guide to build my next keyboard. The only difference between mine and this one is that I added an encoder to the right side, and I used 2 Elite-c instead of 2 Pro Micro.

I wrote a build guide for mine here https://github.com/noahprince22/tractyl-manuform-keyboard. Basically just some ball bearings. It's less frictiony than the Logitech trackball I tested in best buy.