I was looking for a bit holder. I liked many of them, but I couldn’t find one that had exactly what I needed or that was easy to modify.

Here is the model I created using FreeCAD. I originally planned to develop a highly modular and parametric design in FreeCAD to enable any combination of components... but that’s not quite what ended up happening :-). I had to take quite a few shortcuts and ultimately assembled the different parts in a rather hasty manner. You can still find some individual components that can be easily reused across various modules. And I’m always available to assist if needed.

In the end, it has exactly the pieces I needed.