Linear Clock

Step 18: Refinement #3 - The revenge of the double bobbin technique

So, the final iteration for this instructable is actually the closest design to the prototype.  It uses the double bobbins, but positioned in a way to make the winding a little more even. And it is also pre-wound much more carefully so that one side fills at a more similar rate than the other empties.

It is still not as simple and as "closed-loop" as the bead chain system, but it is quiet and importantly, it works with these small steppers, which means it is light and cheap.  Design is about compromise, and these iterations are the whole point of making prototypes.  It is very rare indeed that designs drawn out on paper turn into perfect physical objects without a whole lot of shoehorning.