Pulley Systems Rules Knots & Pulleys in Rope Rigging Systems Vol 1 Segment 6 Rigging Lab YouTu

you we're going to talk now about pulley systems as they're used for mechanical advantages and specifically we're going to address these five simple rules for a simple mechanical advantage this is stuff that's been handed down over centuries through the Mariners industry and they still hold true for today and are very useful in understanding these pulley systems the first rule is if the Rope is tied off at the anchor it's always going to be even it's going to be a two to one a four to one a six to one eight to one always going to be even here we have a two to one it's tied off at the anchor rule number two says if it's tied up at the load it's always going to be odd it's going to be a three to one a five to one seven one in this case we have a three to one if I were to pull from right here it would be a three to one rule number three addresses this pulley right here rule number three states that the last pulley at the anchor where the rope goes to the Hall team is a change of direction and it really doesn't offer us any mechanical advantage it's simply a convenience as a change of direction okay another way to think about this any leg of rope that goes from an anchor myself as a Hall team in this scenario I'm part of the anchoring system so any leg of rope going from an anchor to an anchor offers no mechanical advantage it's only these legs of rope that go from anchor to load they give us the lift and the mechanical advantage change the direction rule number three let's look back here again rule number one if it's at the anchor it's always going to be even rule number two at the load it's always going to be odd rule number three the last pulley at the anchor is a change of direction okay rule number four and we can stay right here rule number four states that you can count the number of pulleys add one and that's going to tell you what the mechanical advantages so let's pretend we don't have this CD here and I'm just going to halt from right here and we have this three two one zero I have one two I had one and it says I have a three two one another way to look at this is I have three legs of rope going from the anchor system to the load where this press ik is one two three I'm pulling on one and I have three working for me hence the three two one okay our last rule rule number five states a simple pulling on the Hall of another simple mechanical advantage becomes compounded and you multiply those two so what do we have here we have this blue rope that's an obvious two to one and it's pulling on the end of what we have rigged here is a five to one how do I know it's a five to one well let's go by our other rules it's tied up at the load so I know it's going to be odd I have how many pulleys will I have a double shove here so there's one two and I have another double ship up here three four I have four pulleys add one that says it's a five to one okay I can also count the legs of rope between the anchor in the load and I have one two three four five so all my other rules are incorporated right here as well this is a five to one if I were to pull from right here but say this is just not giving me enough power and I'm really I'm really getting wasted I need more horsepower on this thing so I can quickly add a two to one represented by the two the rope here so I have the two to one multiplied times the five to one this is a compound ten to one what's the trade-off nothing in life is for free is it the trade-off is I have to pull ten feet of rope here to move that load one foot but it's relatively 10 times easier discounting any of the friction and stuff within these pulleys themselves

Channel: Mike Maggard

Views: 119,660

Rating: 4.8334842 out of 5

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Id: 9L-LJvz-cZM

Length: 5min 30sec (330 seconds)

Published: Tue Aug 12 2014