You don’t have an ‘8’ you have a compound 12 to 1. You have a simple 3:1 pulling on a simple 4:1. Compound systems are products of the simple systems. So a simple 3:1 pulling on a simple 4:1 the product is (3x4)= 12.
It looks like you have 3 to 1 ratio ( aka Z rig) pulling 4 to 1 setup. If that is true then you have 12 to 1 mechanical advantage, instead of 8 to 1 ratio.
It's 3:1 x 2 If you tie st the load it is 4:1 The way you did it the 4th pulley is a redirect. Tie at the load and the number will always be even. Tie at the anchor and the number will always be odd. Just by switching where you tie can gain you an extra advantage. Always tied to the load if possible. Other than that very nice gear!
He makes a video on compound pulley systems and don’t even know the correct MA he’s getting. It’s a 3:1 pulling a 4:1 which makes its a 12:1. It a common 3:1 z rig setup, he needs to include the 1 unit of tension coming up from the base pulley to the prussik, that line is still helping pull the load.
It’s not just a CD because it doesn’t terminate at an anchor, but instead adds 2 units of tension to the haul line. Add the 1 unit of tension from block at the base of the pole and you have 3 units pulling on the 4:1. Giving you a TMA of 12:1 at the load.
Right when you put a block with the moving part on the hulking part you multiply the advantage. If they get a book on rigging they will also learn the correct names for the rigs and gear. Then when they go t a store to buy some thing they will get what they need and not dumb looks like their dumbass deserve.
It is a 12:1, that pulley anchored in the middle of the rope gives a 3:1 mechanical advantage (google up "z-rig"). A 3:1 multiplying a 4:1 gives a 12:1.
In SmarterEveryDays video on the compound pulley section he only had 2 units of tension working on the next set of pulleys. In this video there is 3 units of tension being applied to the rope beyond the prusik hitch, therefore you have a 3:1 system working on a 4:1 system creating a 12:1 compound pulley system.
