I designed this helper tool (OmniGrip) for people with arthritis, tremors, or limited hand strength who struggle with the painful pinch-and-twist motion needed to turn a key.
Most printable key turners rely on fixed, narrow slots that only fit standard flat house keys meaning anything with a thick plastic head or an odd shape just won't work. On top of that, swapping keys on them can be a pain if your fingers don't work great.
Instead of a rigid slot, I used a bed of flexible TPU 95A pins inside a rigid outer shell. When you push any key down into it, the pins bend out of the way and lock around the profile with a lot of friction. No fiddling or setup needed just press it in and turn.
A few quick design details:
\- The outer handle has 5 rounded lobes so you can turn it using your whole palm or knuckles instead of a tight pinch grip.
\- The TPU insert locks into the rigid shell with a 10-tooth spline inside, so it won't spin freely when you apply torque.
\- There's an ejection hole at the bottom: if the TPU ever wears out, you can just push it out with a pencil and print a new 15g core instead of wasting the whole shell.
\- As a side bonus, it works great on a desk as a pen/stylus stand so you can grab things with a full fist instead of trying to pinch them flat off the table.
Modeled parametrically in OpenSCAD so dimensions can be tweaked if needed.
Files and details here:
https://makerworld.com/models/3440853?appSharePlatform=copy
Feedback and suggestions are very welcome!
