Pulley system composition – a systematic approach (2020)(kiipeilytuomas.fi) |
Pulley system composition – a systematic approach (2020)(kiipeilytuomas.fi) |
However, the author does not "appear" to have the Luff Tackle variation. [1] I think it's close to the 6:1 variation on row two, except with the pulley directly attached to the ceiling.
The systematic approach seems to work, just appears to be missing a few combinations, or it was not really systematic. Such as, their should probably be a lot of pulley combinations that are basically "nothing", or "not helpful" combinations. 1:1, or 1/2:1, ect... combinations that just noted as discarded (or maybe curiosities that "might" have a use)
A 1:1 pulley is not "technically" significant from this perspective, yet it does change the force direction.
[1] https://en.wikipedia.org/wiki/Pulley#Method_of_operation
Maybe it's implied, yet the author didn't seem to care about fast, and mostly appeared to be counting whole numbers for greater lift. Guess most of the furthers probably also have uses if force is not an issue 1/3:1, 1/4:1, ect...
Sailing's not one I'd thought of much. Guess if large scale sailboats ever make it around again, hauling large scale ripstop nylon clipper sails might use a really fast spinnaker halyard.
I honeslty think this should be taught in school, not just in physics classes, but as part of some kind of a "Life 101" course.
With ropes you can start with a basic loop that acts as a pulley. Butterfly, wireman's loop, farmers something - I forget the names.
But you basically create a loop that let's you double back your rope. With a lot of modern rope they are slippery enough you get pretty good mechanical advantage. Some folks then go to a taught line hitch or something to even keep things adjustable basically. Key is usually to give yourself enough space to tighten, and I skip the taughtline hitch in most cases.