5 to 1 fiddleblock set

Re: 10 to 1 fiddleblock set

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Wow! Where's the hauling line?

You're using the wrong term. Each block has 5 <u>SHEAVES</u>.

from http://members.aol.com/donnl/gloss.html
reeving: A term used to describe the path of the wire rope through a system of blocks. A reeving diagram is a pictorial rendering of the desired path for the wire rope.

Your photo shows the "natural" instinct to have all of the rope runs parallel and the two pulley axles parallel. I've never used more than 2 double pulleys in a MA system, but as I understand, when using more, the convention is to have the two pulley axles oriented at 90-degrees to each other. I suppose that the reason for that is probably to avoid rope twisting. It's most likely not an issue with us anymore, however, because of the use of braided rather than laid ropes.

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Thanks for the info on the correct terms and the pdf on reeving. I've only used this system a few times and I'm sure it is going to work better with a modern rope and reeved correctly.

The hauling line is shooting over the right side of the camera. It is tied off to a tree and I've got a block of wood hanging in tongs to keep the ropes straight (not shown in the photo) . The rope is manila 3 strand and does want to twist up with no load. I'm sure the hauling line coming from the middle of the top block Vs. how I have it coming from one side is going to work a lot better.

I have no idea how old these blocks are. They look military.
 
Re: 10 to 1 fiddleblock set

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Here's what I'm talking about:

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Looking at my photo I can see how I'm side loading the end sheave by my incorrect reeving. I'm lucky to only have about 40 lbs. load tied off on the system. If the line were coming from the center sheave the top block should automatically rotate towards the hauling line pull direction and this side loading should not be a problem. Luckliy all of my lifting has been from standing almost directly under the blocks so I don't think I've done much side loading.
 
Re: 10 to 1 fiddleblock set

Yes, it will usually twist to reoirentate unless relaid correctly. On multiblock systems we must also look out for the total friction loss building up(in axles and rope rubbing losses). It may well take another sheave on the load to bring a system up to the calcuyalted potential of what we need.

Here are some old pulley drawings from masive ships, where most of this and 90% of knots come from:
http://mytreelessons.com/Marlinspike_%20Sailor.htm

http://mytreelessons.com/Marlinspike_%20Sailor_Rig.htm

Also shown are how one system pulls on another, even as an inset, to '2hand' it and the greater multiplying there in.
 
Re: 10 to 1 fiddleblock set

Thanks Treespyder.

I'm going to get it right and get more pics.
 
Re: 10 to 1 fiddleblock set

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Here is a 10/1 fiddle block.

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Those are not fiddle blocks, but simply blocks. The setup is a block and tackle.


From the link provided by fhfr436:



http://members.aol.com/donnl/gloss.html




fiddle block: A block consisting of two pulleys in the same vertical plane held in place by their common cheek pieces.



Fiddle blocks supposedly got their name because when viewed as in the attachment they look like the musical instrument 'fiddle'
 

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Re: 10 to 1 fiddleblock set

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Those are not fiddle blocks, but simply blocks. The setup is a block and tackle.

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Thanks Mahk. Block and tackle it is!
beerchug.gif
 
Re: 10 to 1 fiddleblock set

Yeah, wasn't going to call him on'dat, but that is most correct. The fiddles can give more pure inline force, for closer to calculated potential/ less loss from non-inlinedness, and less rope rubbing (in properly sized ropes). But, then less efficiency/ more loss in the area of the smaller sheaves having less leverage over the axle/ there for less efficient.

There all ways has to be some friction loss. It is the law of conversions. This friction loss will be from the axle to sheave/bushing/bearing X the sheaves outer circumference to the axle ratio. Thus, everything else being equal, a larger sheave will be more efficient than a smaller one on the same sized axle. Bushings take more shock than bearings, but bearings are more costly and efficient. This efficiency can be so sought after that one might pay 2x as much for 8% more efficiency.

The lower efficiency works against you in compressing a jig; but it works for you in holding and lowering! form then friction is your helping friend. The friction/ efficiency loss is a multiplying effect, building up; but per sheave, not just on the load sheaves like the power itself. It is common practice to place the most efficient sheaves first in your pull for more compression efficiency overall; but i think that actually works out to be in load/anchor pairs, rather than efficiency in single units.

Other losses come from rubbing lines, and non-inline lines. Usually we think of leveraged increase as changing direction; perpendicular, rotational force. But here, we have non changing direction input/ output over the course of the work; and pure inlineness rather than perpendicular force being maximum. Also, the inline strategies of pulleys are multi legged, and other leverages are generally, or can be single leg. Because to have perpendicular/ rotational leverage; we must operate through a stiff device, that resists bending; It is then the resistance to the bending that operates to give such leverage. Rope is not such a device; except, after it is pretightend; then it resists bending. This is where sweating or swigging a line comes in; bending a tightened line for leveraged return; without frictional losses. So many times i might use inline MA to pretighten, then the real tightening would come in bending said line(s); especially in tie downs.

knudeNoggin also notes one study that the 3:1 calculated potential return on a non-pulley/ all rope zrig is actually closer to 1.65. So, i mihgt hise that as the pretighten, then the real leverage tightening in the bending comes in. The tighter it is, the less it bends at the same sidewards pressure; the higher the multiplier of that sidewards tension.

MTL-Pulley Power Patterns of forces on Loads and Anchors (also shows the sometimes elusive Spanish Burton etc., that bears out some of the Mayhem and 2handing/inset strategies)
MTL-Spread Angles
MTL-Sweating In Leveraging
MTL-Tie down strategies

MTL-Mayhem Puzzle (G)
 
Re: 10 to 1 fiddleblock set

i've talked to Mr. Brion about this before; i think we can get 3rd class lever system by pulling from the pulley and taking output on 1 end of the line while anchoring the other end of the line. Classically with a single pulley, this will give a 1:2; as in pulling brush 100' out of back yard with only 50' of truck run example. This gives power loss/speed gain, and same direction of movemeant for input effort and output on load(classic 3rd class lever identifiers).

A pulley by itself is all ways a 1:1 1st class lever(1st class levers are the only class that has the input and outputs moving in opposite directions); but even with that insight; a pulley is recognized as a separate identity in the list of the simple machines(which might be 5 or 7 depending on who is counting). Decidedly separate from lever, and differently than wheel/axle, for a pulley proper spins around axle, doesn't spin the axle to have a change in leverage output that way. A 1st class lever has a center pivot between input and output, and the input and outputs move in opposite directions. In a system it is more like pre-scribed above. In these rope examples, i take the anchor/ non moving part as the pivot. But, anyway; we are showing that the 1st class lever of the pulley; si then taken as a 1st, 2nd or 3rd class lever by it's placemeant in the system. On the anchor/pivot as a 1st class, on the load/output as a 2nd class and on the effort/input as a 3rd class lever.

Actually, i kinda don't like calling this leverage; for all other levers are not inline, and are rotating and direction changing; also these pulley/flexible lever systems work on the amount of leg pulls, not on the angle to the device. For example, changing the angle of a leg on a table changes it's leverage; but we don't say that adding a leg changes the leverage like we do with pulleys.. But, in yielding to this popular example; i believe the 3rd class leverage system must then be recognized in these pulley class systems.

A classical 3rd class system has the pivot on an end and the input closer to the pivot than the out ut on load. The input effort and the output on load move in the same direction. Therefore the load has leverage over the effort; but speed/distance are increased from the input to the output. For clarity, i like speaking in 1st class and non-first class lever lingo only. For, if a 1st class lever we can increase or decrease power or just reverse direction with the same power. In non-1st class increases in power are 2nd class and decreases are 3rd class, direction is all ways the same. But, then is a 1:1 non 1st class a 2nd or 3rd class by these definitions?

The real deal with any of this is, the transmission example i think. We are just taking a power source, and trading distance for power; from that finite power source. For there can be no loss or gain in the potentials only this trading. When we pull a 2:1; we have to shorten both legs of pull on the load 1" (for a total of 2') to move the load 1'. The load then also moves at half the speed of your input effort. Another note for arborists and DdRT; this is a 2:1 system(less frictions) when you are climbing up it by pulling on 1 leg of the 2 lines of pull on you (or descending same). Whereby 2x as much line moves through your friction hitch as your bod(the load) actually moves. The frictions work against you only in moving up; but work for you in descent or stand still.

For a real twist; this shows how to use a pulley redirect to place 2x force on load, even though the load only has 1 leg of pull, and the forces are inline. It does this by capturing the pull on load and the equal and opposite of that pull, and placing both distance x force modifiers onto the load. 1st 2Handing example

Sorry, i jest luv dis'chit!
 
Re: 10 to 1 block and tackle

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this was fun.

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Great video!

I lifted some 36 inch diameter oak rounds onto a log splitter with my 10/1. It was a lot of pulling but it worked well. I still don't have mine reeved correctly but will correct before I use it again.
 
Re: 10 to 1 fiddleblock set

[ QUOTE ]

Those are not fiddle blocks, but simply blocks. The setup is a block and tackle.

fiddle block: A block consisting of two pulleys in the same vertical plane held in place by their common cheek pieces.

Fiddle blocks supposedly got their name because when viewed as in the attachment they look like the musical instrument 'fiddle'

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Thanks for the insight. I had never heard the term fiddle blocks until I got into tree work.
 
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