Winching a 4X4 with snatch blocks - two examples
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- Опубліковано 10 лип 2024
- #winching #snatchblock #recovery #4x4
Brief description of how snatch blocks may, or may not give you a mechanical advantage in a 4X4 winching situation by answering a question posted on my Facebook page.
Post any questions in the comments!
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This is GOLD. Thank you for sharing. cheers
Glad you enjoyed it!
Absolutely brilliant explanation. Thank you for the video. Really appreciate it.
Glad it was helpful! Please share :-)
Thanks for all the technical information.
great run through, i use them for pulling trees. love all of the details.
Good Stuff, Great Help, Good Tips 👍Thanks!
Great information and explained very well.
Thank you! Please subscribe :-)
Exactly the information I was looking for!!! Thank You
Glad it was helpful! Please share :-)
Great explanation and graphics to help clarify things for folks. Seen some long time “recovery” folks still try to use “C”.
Thank you !
An absolutely excellent video!
Thank you kindly!
Awesome video
Thanks!
Great information but decided to and ordered your handbook to keep handy in vehicle
Nicely explained . I learnt something !
🙏 Thanks
Thanks please share 👍
I understand the theory of the last part of the video; however, I still can't picture everything hooked up and how all the lines run. Very good for sure!!
Have a look at my other videos on winch rigging...let me know if that helps
great stuff! Never learnt this scenario in school but basic pulley calculations only.
Thanks please share 👍
Just FYI, I just subscribed. This channel is legit.
Thank you :-)
Well explained, cheers 👍
Thanks please share 👍
Thank you, sir! Good explanation
, cheers . . .
Glad it was helpful! Please share!
thank you for detail video
Glad it was helpful!
Very interesting! Thanks!
Glad you liked it! Please share!
Nice content. It's odd that you don't have more views.
@@L2SFBC your information is solid, and those who could actually use the info will appreciate it. Your channel will grow!
Wow great information.
Glad it was helpful! Please share :-)
Great explanation and graphics. Thank you, it helped me wrap my brain around how you get mechanical advantage or don't when using one snatch blocks (single vehicle graphic A & B)
I do have a Question, if you don't mind. On two vehicles graphic A would you not get more mechanical advantage if H was connected to I instead of a tree anchor? Like in single vehicle graphic B. I hope that question makes sense. thanks
Brilliant! . very well demonstration & clear explanation , Thank you
Hello Robert, thank you for sharing all your knowledge with us! I am fairly new to winching and your videos are helping a lot.
Regards to Example A at the 10:00 mark. If you attach "H" to "I", than you would have a 2:1 MA but the red vehicle would see 500kfg of pulling force? So, I guess the main reason to have "H" anchored to a tree is to reduce the pulling force on "I" (if, for example, the winching vehicle is much lighter than the stuck vehicle?)
Correct, for a 2:1 MA where the winching vehicle is static you don't need to attach the return line to the car.
You should link to the book in the video notes.
Thanks Robert, enjoy these videos. Is there a calculation I can make myself aware of to work out the casualty load understanding one wouldn't get a protractor out. 20% incline, 3.2T vehicle (casualty), no obstruction, just slippery hill with no traction left?
Yes, I'll cover that in future videos
Danke!
Really appreciate the Super Thanks, Sassan!
Would you say a 90 degree rope angle off the pulley is about the most you should go ? Have you ever seen a snatch block failure ?
Any degree is fine, no not seen one fail.
Hi Robert
I am a beginner at 4WD and these videos are very valuable. Thank you
I was confused as to how to determine if I have a mechanical advantage or not. The images of the the pulling vehicle on Example C at the start of the video and the pulling vehicle on example A of the redirect set up, look the same. However only one has Mech' advantage. I worked out why in the end. Just for ease of figuring this out out on the field, can I just look at the rate of vehicle advance vs the length of line pulled in by the winch? IE vehicle advances half a meter for every meter of line pulled?
Thank you
Elisha
Hi Elisha - yes that works too. There are various ways to work out MA, some work for some people, others not. Your method is good. Glad you found the videos helpful, please share/subscribe etc :-)
If the car moves forwards 1m for every 1m of line pulled in, then there's no MA, regardless of however many blocks the rope goes around. This is a big misconception; I have another video on that subject specifically.
Yeah, that's where I'm confused. The only difference between the examples was the additional pulley. I'm guessing some of the load is distributed to the second pulley which is what provides the MA?
What are these meaters and killagrams you speak of?
A killagram is opposite to a killawasp - you want more killawasps, and fewer killagrams, so named because they kill performance. And I said "metres", eat more vegetables your hearing will improve :-)
Question on the last one 11:00. Say H would it be better to attach back to the winch vehicle to give a better pull?
hmmmm. thought the same thing?.. because your first demo a,b,c.... on C there was no mechanical advantage but on B it cut it in half so on the last one I thought H should be hooked to the winch vehicle instead of a tree off to the side
Is a snatch block the same thing as a 1:1 or double purpose? I have heard these terms and wondering it they all mean essentially the very same thing as to how they relate to a chain hoist or cable hoist/cable puller or come along? Thanks for any input.
Hi - no short answer sorry. Check out my videos on snatch blocks for a full answer.
All very interesting and well detailed depictions but somewhat confusing. At about 2:90 you say C is EXACTLY the same as B but it looks so different and the dialog says the forces operate differently in multiple ways which has me feeling it's quite dissimilar so I'm doing multiple viewings hoping I can eventually grasp their exactness and make worthwhile use of it.
2:90 ?
@@L2SFBC My guess is 3:30
Don't really understand all that about the blocks, but as i don't have a winch it doesn't really matter. Why would reversing up a hill put more stress on your CV joints and front diff when compared to driving forwards?
Because there is a weight shift to the downward part of the vehicle when on a slope. Also, diffs are designed to be stronger when forwards compared to backwards. So, try not to reverse up hills and if you do, be smooth, and keep the steering wheels straight as the more lock you apply the weaker the CV.
Very interesting diagram info. Unfortunately, in the real world, almost all of these methods require a tree (or trees) in perfectly placed spots. Where I live, there usually aren't any trees, and if there are, they aren't where you need them.
Shouldn’t H be attached to truck on last example?
No why?
@@L2SFBC thanks for all your great video. I greatly appreciate you teaching us. I thought it would give more mechanical advantage if it was attached to truck on “h”.
Thanks again!
I’m sorry but this is the mistake that most people make. Ex A is a one to one. Ex B is a one to one with a redirect. While it is true that the weight is distributed over 2 lines, this does not create a mechanical advantage. The winch is still pulling the same amount of weight. Only pulleys that are moving(that is changing its position from point A to point B create a mechanical advantage.
Read this then comment again l2sfbc.com/you-can-get-mechanical-advantage-from-a-snatch-block-that-doesnt-move/
1:20 stationary blocks as in B don't give any advantage, they just change the direction
No way... I could not pull my self stright out once. I then hooked it up like B and it came right out. It was slow but it worked
Bart is correct..the misconception a block must move for MA is wrong. Just watch my videos.
I get what you’re saying and it’s true that weight can be created but the pulley in this example is not creating a mechanical advantage. Let me explain it another way. Food for thought. Let’s take the snatch block out and for sake argument let’s just hold the line in our hands. If the line is coming from the winch to one hand the to your other hand and back down to the vehicle then each line and hand is holding half the weight. No mechanical advantage as you are still holding the entire weight. If you were to take the end off of the line off the vehicle and attach it somewhere else, it’s not that weight is created, it’s now that each hand has to hold the entirety of the weight thus doubling the effort. Now if you want to make an argument that mechanical advantage is being created, the only place it can be happening is at the winch itself which is acting as a pulley as it pulls the line in and is in fact a moving pulley. Let me know what you think.
l2sfbc.com/you-can-get-mechanical-advantage-from-a-snatch-block-that-doesnt-move/
@@L2SFBC this is the same reference you gave me before. My comment above is in reply to this second video you are referring to. Again while I understand what you are saying, at the end of the day, there is no maechanical advantage when the end of the line starts at the load and goes thru a pulley at the anchor. The only possible way that mechanical advantage is being created, however little that may be, is at the winch itself which is acting as a pulley as it is pulling the load in. There is no mathematical or physical way mechanical advantage is created on a stationary, redirect pulley. I feel you are not taking in my observation but that’s ok. Just wanted to share
You don’t have more views because you are wrong. You cannot create weight by attaching to a tree, your force will still be 300kg not 600kg. Way too many other mistakes here to elaborate on, it would be a complete reversal of most information here.
Hi Brad. I'll create a video so you can see why I'm right, and you can replicate the experiment yourself.
Then, please can come back here and comment again.
Brad, Robert is widely respected as an expert in this field. He’s the author of multiple books that have been peer reviewed by the likes of myself, Bob Wohlers and others who specialise in this space. I would be very cautious calling Robert wrong as you have. My first question would be to ask for clarification coming from a position that I might be wrong. As for the views I don’t think Robert is worried about lots of views but rather having a resource for us to reference.
MadMatt 4WD Matt, You are correct, Covid must have had an affect on my manners. I will make my apologies to Robert and ask for clarification on the parts I have questions with. Thank you for the heads up. Kind Regards.....
@@BradIXXI FYI I use Robert as a bouncing board for much of content and he does the same with me just to ensure we're getting things right. He isn't always right but he has a lot of good info like all of us.
L2SFBC - Robert Pepper - auto journo Robert, I will attempt to replicate the senecio this weekend at my shop. I was rude with my earlier comments and should have asked for clarification rather than making an aggressive statement. I mean no disrespect and in no way justifies my rude behavior, but I’ve seen so many videos on snatch blocks and pulleys that are actually dangerous behavior that I let my mouth run before my brain caught up. My apologies Sir......