The yellow machine winds a 3-strand hawser-laid rope, using Lego Technic components. You can see how the Technic gears are used to guide the three colours of yarn out of the spools and wind them into a cord before they are wound in the other direciton to lay up against each other in a rope.
After my mechanical loom is 2012, I wanted to build more specific weaving and braiding machine. After months of research, I came back with a new idea based on rope maker : a braiding machine which can make of course rope but also wristband ! Then, I have started in April of 2013 to make some prototype of weaving and braiding machine and succeeded in making one truly functional in December of 2013.
The Red machine is more complicated- it makes a braided rather than a hawser-laid rope, and is also faster.
Nico71 provides free (simple) and paid (highly detailed) versions of the building instructions for both of these, as well as a Youtube channel with demos of these and many other Lego machines.