User Panel
Posted: 12/7/2019 11:26:41 PM EDT
I never knew how pulleys worked until I saw this video. Pretty cool.
Why Snatch Blocks are AWESOME (How Pulleys Work) - Smarter Every Day 228 |
|
As someone that grew up on sailboats I am confused why people get confused.
|
|
The simple machines unit was easily the best unit of all of elementary school.
|
|
To oversimplify things, they're basically the rope version of hydraulics/pneumatics.
|
|
Modern!?
I know for a fact that they date back hundreds of years. I'll never forget seeing Burt Lancaster beat the stuffing out of a dozen pirates with one. |
|
Quoted:
The simple machines unit was easily the best unit of all of elementary school. View Quote Oh, and a neat lego channel Testing Lego gear and pulley systems - part 2 |
|
Quoted:
Yup - inclined plane, lever, wedge, wheel and axle, pulley, screw, and C4 View Quote View All Quotes View All Quotes Quoted:
Quoted:
The simple machines unit was easily the best unit of all of elementary school. I told him it would be the highlight of the year for a kid like him. |
|
Spent a lot of time working with them when I designed cranes. On cranes we called them sheaves.
|
|
I keep a couple of snatch blocks in my recovery kit for my truck winch.
|
|
Smarter every day is a good channel. He has a cool video about silencers.
|
|
Guy was confusing. Could have just said that the same amount of work is being done, but you are trading (less) force for (greater) distance. The tension BS is irrelevant.
|
|
|
I have some old block and tackle out in the shop, I need to get it set up. Would be useful at times.
|
|
|
Quoted:
I never knew how pulleys worked until I saw this video. Pretty cool. https://www.youtube.com/watch?v=M2w3NZzPwOM View Quote Seriously? How else are they supposed to work? I use a kit to lift my Jon boat out of the way to the ceiling of my carport. |
|
|
Pulleys and their great great grand children, modern cranes are absolutely amazing.
I only own a small 28tn crane. But even it is impressive. Being able to lift 3000lbs 57 feet away is awesome. |
|
A good rope and pulley is worth its weight in gold to move cut trees around.
Also helped today to get my new pole saw unstuck |
|
So to be clear, his experiment with the stuck jeep provided no mechanical advantage, correct? Simply using the snatchblock alone and moving the pull point from the tree to the bumper did not magnify force in any fashion.
|
|
|
Quoted:
It doubled the force. That's what they do. View Quote View All Quotes View All Quotes Quoted:
Quoted:
So to be clear, his experiment with the stuck jeep provided no mechanical advantage, correct? Simply using the snatchblock alone and moving the pull point from the tree to the bumper did not magnify force in any fashion. I would understand a second pulley, or block and tackle setup where the force is redirected twice. But only being run through one pulley should only change the direction of force, not the magnitude... ? |
|
Quoted: Doubled the force at no sacrifice to distance pulled? I would understand a second pulley, or block and tackle setup where the force is redirected twice. But only being run through one pulley should only change the direction of force, not the magnitude... ? View Quote You trade one for the other. It isn't just a redirection, because it was anchored back to the jeep. |
|
Quoted: Doubled the force at no sacrifice to distance pulled? I would understand a second pulley, or block and tackle setup where the force is redirected twice. But only being run through one pulley should only change the direction of force, not the magnitude... ? View Quote If you're doing an off axis pull, where the winch line terminates at an anchor (tree or whatnot), then, yeah, you're simply changing the direction of travel between the Jeep and the anchor. |
|
Quoted:
Nope. If winch is pulling on the line and the other end of the line is pulling on the bumper, the bumper is being pulled by twice what the winch can haul. The Jeep moves at half the reel speed View Quote |
|
Quoted:
Nope. If winch is pulling on the line and the other end of the line is pulling on the bumper, the bumper is being pulled by twice what the winch can haul. The Jeep moves at half the reel speed View Quote View All Quotes View All Quotes Quoted:
Quoted: Doubled the force at no sacrifice to distance pulled? I would understand a second pulley, or block and tackle setup where the force is redirected twice. But only being run through one pulley should only change the direction of force, not the magnitude... ? You're proposing that if the winch were to reel in 12" of cable, the jeep would only move toward the pulley 6"? I still can't fathom that- there's nowhere for that distance to get lost. So is the part of this that I'm missing in the fact that the pull point and the anchor point are the same? |
|
Quoted: As a guy who (I thought) had used pulleys effectively as a wrecker operator, I'm feeling pretty stupid about this, but I'm going to keep talking through it until it makes sense. You're proposing that if the winch were to reel in 12" of cable, the jeep would only move toward the pulley 6"? I still can't fathom that- there's nowhere for that distance to get lost. So is the part of this that I'm missing in the fact that the pull point and the anchor point are the same? View Quote The key to it is that the end of the cable is connected back to the jeep. That doubles the force. If you connect it to anything else, you redirect the force but do not double it. Physics wont give you something for nothing, but it will trade with you. |
|
|
I look at pulleys similar to a gear reduction system. You're trading displacement (movement) for power.
|
|
Quoted:
Yes. The cable is doubled on itself so the distance that the object travels is halved. The drum is still moving at the same speed as always but the cable has to cover twice the distance to move the object as it normally would in a straight pull. The key to it is that the end of the cable is connected back to the jeep. That doubles the force. If you connect it to anything else, you redirect the force but do not double it. Physics wont give you something for nothing, but it will trade with you. View Quote That's exactly what the pull does. |
|
|
I remember rigging a block and tackle out of scrap and loose pulleys to haul some heavy boxes up into the attic. my nearly grown kids thought it was magic.
|
|
Had he consulted modern sailboat racers he would've had his mind blown.
Attached File Attached File Attached File |
|
Great video.
Loved the old guy who turned up and just knew how to do things. Dying breed around here |
|
Always loved Destin's channel and I know he is an actual rocket scientist, but the way he stood and filmed near the anchor point of the winch of the Jeep made me cringe. Ever see an anchor or winch cable fail under load? Someone posted a liveleak video of that happening here a while back. Snatch block came back through the windshield and made the poor driver's face look like the Predator.
|
|
Quoted:
Nice post. I had 5 acres of bull pine, and lodge pole logged on my property so I've got an awful lot of stumps to pull. I bought this to refresh my memory on pully's, there's not much to it that isn't in this manual. https://www.AR15.Com/media/mediaFiles/103648/IMG_0197_JPG-1187477.jpg View Quote |
|
Quoted:
I look at pulleys similar to a gear reduction system. You're trading displacement (movement) for power. View Quote |
|
Quoted:
Had he consulted modern sailboat racers he would've had his mind blown. https://www.AR15.Com/media/mediaFiles/234934/20191208_062035_jpg-1187684.JPGhttps://www.AR15.Com/media/mediaFiles/234934/20191208_062035_jpg-1187685.JPGhttps://www.AR15.Com/media/mediaFiles/234934/Screenshot_20191208-062757_Chrome_jpg-1187693.JPG View Quote |
|
Quoted:
Always loved Destin's channel and I know he is an actual rocket scientist, but the way he stood and filmed near the anchor point of the winch of the Jeep made me cringe. Ever see an anchor or winch cable fail under load? Someone posted a liveleak video of that happening here a while back. Snatch block came back through the windshield and made the poor driver's face look like the Predator. View Quote |
|
|
|
Quoted:
Love pulleys? Here you go!! https://www.AR15.Com/media/mediaFiles/71410/plot_combine-649966_JPG-1187718.JPGhttps://www.AR15.Com/media/mediaFiles/71410/plot_combine-649966_JPG-1187719.JPG View Quote |
|
Quoted:
I've never seen that book. Looks handy. Off to Amazon. View Quote View All Quotes View All Quotes Quoted:
Quoted:
Nice post. I had 5 acres of bull pine, and lodge pole logged on my property so I've got an awful lot of stumps to pull. I bought this to refresh my memory on pully's, there's not much to it that isn't in this manual. https://www.AR15.Com/media/mediaFiles/103648/IMG_0197_JPG-1187477.jpg https://manuals.directutor.com/HPE/Rigging-Handbook.fm5-125/index.html?page=1 |
|
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.