People think pulleys increase pulling power.

Factoid

Three criminal heroes
Can you run half the engine?

I used to be able to run half the engine. The 2012 Camaro engine I put in my 1988Defender had DOD that would shutdown up to 4 of the 8 cylinders. I disabled it in the ecu once in the LR.
 

PovPack 80

New member
The snatch block can be though of as a spinning lever.
Spinning Lever.jpg
If the Snatch Block is rigged as a class 1 lever, you don't get a mechanical advantage.
class 1.jpg
If the Snatch Block is rigged as a class 2 lever, you get a mechanical advantage 2:1.
Class 2.jpg
Hope this helps
 

MOguy

Explorer
The snatch block can be though of as a spinning lever.
View attachment 440660
If the Snatch Block is rigged as a class 1 lever, you don't get a mechanical advantage.
View attachment 440661
If the Snatch Block is rigged as a class 2 lever, you get a mechanical advantage 2:1.
View attachment 440662
Hope this helps
This is how I always saw it but in the 1:1 If you run it back to the jeep it becomes 2:1. The tree pulley is change of direction and the winch on the The winch becomes a pulley carrying the load. This what has hard for me to see.
 
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Fireman78

Expedition Leader
Have you heard about the new Yeti Axe with a 4:1 mechanical advantage? It’s only 379 bucks but I’m holding out till it comes with a cup holder.


Sent from my iPhone using Tapatalk
 

rickc

Adventurer
This has been entertaining; lots of good points but I think Robert is the only one that answered the OP's starting question (thread page 5). If simply pulling yourself out of a ditch/up a hill whatever using a tree/truck as a base it's always best to run the cable out as far as you can, leaving at least 5 or 6 wraps on the spool because this provides the most mechanical advantage from the winch. If you are unable to run the cable out a good distance then the alternative is to use a single pulley at the base and connect the hook end back to your vehicle or another base. The pulley is not providing mechanical advantage itself but it's allowing the winch to pull harder due to increased efficiency.

The amount of cable on the spool increases/decreases working load depending on amount of line on the spool. Your winch is rated on the first wrap of the spool but obviously you can't safely pull on that wrap, you need a safety factor. Each successive wrap decreases your pulling power but that doesn't change your mechanical advantage, it only explains why you may need to increase your mechanical advantage i.e. add more pulleys into the system to make up for lost power- which will obviously require more line. This is why most recommendations are to go at least 1.5x your vehicle weight.
 

JPaul

Observer
This has been entertaining; lots of good points but I think Robert is the only one that answered the OP's starting question (thread page 5). If simply pulling yourself out of a ditch/up a hill whatever using a tree/truck as a base it's always best to run the cable out as far as you can, leaving at least 5 or 6 wraps on the spool because this provides the most mechanical advantage from the winch. If you are unable to run the cable out a good distance then the alternative is to use a single pulley at the base and connect the hook end back to your vehicle or another base. The pulley is not providing mechanical advantage itself but it's allowing the winch to pull harder due to increased efficiency.

The amount of cable on the spool increases/decreases working load depending on amount of line on the spool. Your winch is rated on the first wrap of the spool but obviously you can't safely pull on that wrap, you need a safety factor. Each successive wrap decreases your pulling power but that doesn't change your mechanical advantage, it only explains why you may need to increase your mechanical advantage i.e. add more pulleys into the system to make up for lost power- which will obviously require more line. This is why most recommendations are to go at least 1.5x your vehicle weight.
Here we go again. This statement would be true IF you were only using the pulley as a direction changer and did not hook the cable back to the rig. If you run the cable from the winch through the pulley and to another fixed object like another tree, then yes there is no mechanical advantage.

However, by running the cable from the winch through the pulley and back to the winch (bumper) then you gain a mechanical advantage of 2x. The winch drum itself is considered a single pulley, so when used by itself it is a 1x force multiplier. Adding a second pulley (the one attached to the tree) and attaching the line back to the same point of the first pulley gives you a 2x multiplier.

Look at this image:

900px-Four_pulleys.svg.png


The first one with a single pulley is representative of a winch attached to a vehicle and the "load" being the tree or rock or whatever. Something to keep in mind is that if your vehicle was locked in place it would be trying to move the load (tree, rock, etc) and not the vehicle. The reason a winch works for a recovery is the the load it is pulling on has a greater resistance (weight, resistance to force, whatever) than the vehicle the winch is mounted to. Think of a towtruck, it weighs more than the vehicle it is pulling and has more resistance so the vehicle it is pulling onto the bed is what moves and not the tow truck itself. The same thing happens when you choose an anchor point for the winch cable that does not have enough resistance, so it ends up moving instead of your stuck vehicle. Pick too small a tree or a loose rock or too soft of sand/snow and you move the load instead of your vehicle.

Since the first pulley is actually the winch drum, we can easily see how a pulley attached to the load with the cable run back to the same mounting point as the winch (or first pulley) you obtain a 2x mechanical advantage.

If you then add a third pulley to the winch mounting point and then run the cable through that back to the "load" (tree, rock, land anchor, etc) the you obtain a 3x mechanical advantage.


I think this is everyone's hangup that doesn't agree, they aren't viewing the winch as the first pulley, and/or they are viewing the load as the vehicle, when it's actually the anchor point (tree, rock, etc) that is the load and we're just counting on the vehicle moving more easily than the anchor point. The force being applied to the cable and load (anchor point) is being provided by the winch motor via the first pulley which is actually the winch drum.

I hope this helps.

Sent from my SM-N950U using Tapatalk
 
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rickc

Adventurer
JPaul: humble apologies, I wrote too fast; I meant simply to stress the impact of having a long line and fewer wraps. A double pull connecting to the vehicle does provide mechanical advantage from the pulley as well indicated in picture 2.
 

Mundo4x4Casa

West slope, N. Ser. Nev.
I'm sure glad I missed this one, all entertainment aside. I've never had use of a pulley for vehicle extraction, but various snatch blocks, comealongs, and high lift jacks, yes. I've had 6 or 7 winches in my time of all stripes. I bought my first snatch block from my friend ******** Cepek in 1967 as his little 25 foot wide store front was only a few miles from my home. The pin was 1.25 inches thick and the hardware was way overkill for my Land Cruisers. Of the maybe 500 winch pulls I've done, about 10% were with a snatch block, and the hook was hooked right back to the wincher producing an 'almost' doubling of the effort. Only flange drag and friction caused by the cable rolling around the pulley caused the loss. I could feel the result: slower, maybe twice as slow but with some sobriety in the result. None of this is scientific but due to endless field testing. The overriding consideration in winching technique is safety and a slow and methodical with many verbals as to your intentions and all shouting, 'CLEAR!' before any move, and "HOPE!" by any spotter to stop the move if something goes south.

To purposely change the subject, since you've clearly covered the it, here is what I currently use for extractions with my 10,400 pound RAM/ Lance Camper lashup:
Warn 15,000 pound winch on Warn's carrier and wimpy brush guard combo beefed up with additional welded CroMoly 4330 tubing, radiator saver, 2 inch receiver hitch, 26,000 pound test cement mixer D rings. I could just not stomach the several hundred extra pounds of a large steel winch bumper hanging out over the front end. Still, not much crumple zone here. If i had a choice when in the throws of hitting something in front I would aim for the sturdy center section which has the best shear factor.

90 feet of 7/16 or 1/2 inch wire rope (can't remember which) with roller fairlead. When using the snatch block with this, the realistic maximum distance is around 40 feet to the pull.
30 foot, 30K pound test nylon strap with loop ends. It's around 4 inches wide.
20 foot, 20K pound test nylon strap with loop ends
Cat Choker. This is a short piece of wire rope with a ball and socket and loop at the other end arrangement that will surround anything (like a log), cinch up tight to be dragged by a bulldozer and doesn't take up a lot of weight or space. Kind of unwieldy though. I use it to drag logs around the property. But if you have no winch attachment points it will go around anything like frame, sturdy bumper near the frame horn, cross member, spring perch or axle near the spring hanger.
Several sizes of LARGE D rings. You just never know what you are going to encounter. I use ones with a 3/4 inch to 1 inch screw in pin.
2 pair of H.D. cowhide gloves.
a 5 inch wide spread hook with spring loaded safety catch that will attach to my winch's hook (also with the safety catch). No open hooks need apply.
a nylon tree saver, loops on both ends.
I used to carry a 2 ton comealong to tie up or realign any errant chassis or drivetrain parts that may have gone astray, but since I don't Jeep anymore there is really no need.
2- 10K pound cargo ratchet straps. You never know what you will have to try to keep parts together if you roll or crash, or a companion does.
2 ton sissor jack. This is thin enough at full collapse to fit between the fender and tire on a wrecked rig to get it to roll again. When really hard core or with a larger group I carry a 4 foot pry bar to move any misaligned parts.
A 2" receiver stud with at least a 1/2 inch metal loop or D ring that will fit in front or rear of your rig. You never know which direction you may have to pull or be pulled.
Notice I don't use chains. I did that back in the day and they were occasionally snapping and always weighed a lot if you had the correct strenght, and were downright dangerous.
For heavier vehicles, a 12 ton hydraulic jack the correct size to fit under the side of an axle whose tire is flat. Also a jack board: a 1 foot square glued and screwed sandwich of plywood up to 1-1/2 inches thick as a footing for any jacks. This little homemade item has saved me over and over again. Also, a heavy jacket or cotton duck tarp over the top of the wire rope will soften the snap if the cable actually snaps.
For a truck camper I do not recommend or carry a high lift jack. I have both the 48 and the 60 carried over from my jeeping days, but they are largely worthless and not worth the weight penalty as they will only lift on the front of the truck. However, it will "look good" strapped on your front winch in transit.
Essential are sturdy attachment points as described above by other posters. Most newer trucks have adequate straight pull points. My 18 year old RAM, not so much. The Class V (10,000 pound limit) rear hitch is now good enough.
Some last thoughts are: If you have never been a hard core 4 wheeler, skip the winch altogether and be less aggressive. Someone else will pull you out. You don't have enough technique. I know quite a few folks that get a winch and never use it, but have someone else pull them out. Enjoying the smell of ozone I still go looking for the 'edge of stick' even with the truck camper. Needing sand mats and the like are an indication that you need to lower the pressure on your tires. High floatation negates the need for sand mats.
Winch here? nope not yet: the rock garden at Mengel Pass Death Valley

Here? not yet: going upstream (up road?) during a flash flood in Panamint Valley, Death Valley

Yes, here: Goler Wash in Death Valley: this is the trip before I installed Tru Tracs front and rear.


regards, jefe
 
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Mundo4x4Casa

West slope, N. Ser. Nev.
S.E.,
I like your humor. I haven't been a hipster since 1970. We heat our home on the west slope Northern Sierra Nevada with firewood. Wood preparation is a way of life. That's why my post is likely the only one on EXPO that mentions a cat choker for recovery work. We have downed quite a few 100+ foot trees, diseased by bark beetles or drought that have been dropped, slashed, bucked, and split. Actually the log dragging stopped after I bought a tractor. Now I use the bucket, surely not a hipster item.
 

s.e.charles

Well-known member
I fed a wood stove for about 7 years and swore "never again." i'd cut it in the morning, let it season on the ride back to the house, and burn it at night.
 

Mundo4x4Casa

West slope, N. Ser. Nev.
S.E.,
I did that too the first miserable year here, but burning green or unseasoned wood takes too much of it's own heat to burn itself causing a lot of soot in the flue and producing very little actual heat. This sounds too much like the Donner Party to me. I can see why you gave up on wood heat. We're a well oiled machine now and stay a year or two ahead in the 5-chord wood crib which contains mostly oak and fir. We have a very efficient mid-size Blaze King and only use the HVAC to heat the house when returning from a winter trip. We're near the end of the grid and power during the winter is an on and off thing. So, we have a well; run the house from a 575 gallon propane tank; a backup stand alone 7KW propane generator connected to a transfer switch; a huge waste/black water storage capacity, so if all outside power systems failed we could go for about a year with what we have, using the generator sparingly. The main reason for the generator is to be able to run the well pump and flush the toilet, which only becomes an obvious woe after a few days without power.
 

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