Very interesting rope info. I always use the flake method for dealing with my vacuum cleaner cord, but I never knew to call it that. Sometimes I wind line around palm and elbow crossing over midway to make a figure 8, but there's a limit to how long a line you can do that with before it slides free of your elbow!
Using bushings with a spinning nail doesn't get you off for free. Any play in the bushings and any bend in the nail will cause erratic positioning in certain joint angle ranges.
Sliding around a bolt as Nicholas is doing avoids these problems very well. Even if the bolt is not truly round, the distortion in position will be small, and will occur repeatably as a function of joint angle, so it could be calibrated away if necessary.
But you do have to use very slippery line to be able to pull it around more than one turn! If the slippery coating wears off, you'll just have to replace the line oftener.
So it might be important that it's easily re-strung.
Using bushings with a spinning nail doesn't get you off for free. Any play in the bushings and any bend in the nail will cause erratic positioning in certain joint angle ranges.
Sliding around a bolt as Nicholas is doing avoids these problems very well. Even if the bolt is not truly round, the distortion in position will be small, and will occur repeatably as a function of joint angle, so it could be calibrated away if necessary.
But you do have to use very slippery line to be able to pull it around more than one turn! If the slippery coating wears off, you'll just have to replace the line oftener.
So it might be important that it's easily re-strung.