This is a killer reference source and entry point for many applications and projects.
Capstan actuators = rope twisted around two drums for gear reduction, but with limited range of motion.
Very interesting. Thanks! I wonder if it could be used as an axis in a 3d printer
Creep would be a problem. But a fairly solvable one.
Has already been done in different reprap machines. Even in commercial printers like the Fusion3 F400.
It works, but is not widely used
I once worked for a small company that was based around using a patented variation on this. It works really well and creep can be basically eliminated by using multiple counter-tensioned steel cables instead of rope and running a burn in process to let the tension settle evenly. You can even get an arbitrary number of rotations by extending the capstan.
I think the main reason it isn’t used more is that assembly is more difficult due to needing to deal with winding the cables and a general lack of knowledge on how to do it well.
