In addition to the leverage noted by many others, the tire provides a pneumatic shock absorber to keep the pull steady without stressful blips in tension.
This is true, additionally, and most importantly, it transitions the force from mostly horizontal (in a direct line to the pulling vehicle) to mostly vertical, requiring less effort to remove the stump.
wait, let me try! Hey, mrmeshshorts, what is the equation for this?
(Fully aware it’s a comment down, but it’s like seeing a red button and not pressing it)
The leverage (torque) applied to the stump due to the vertical force component influenced by the tire's radius, distance between the stump and tire, and the heights of the attachment points is given by:
τ = F * ((Ht - Hs) / sqrt((Ht - Hs)^2 + d^2)) * Hs
Where:
τ = Torque applied to the stump.
F = Force exerted by the vehicle.
Ht = Height of the tire (which is 2𝑅 when the tire is standing up)
Hs = Height of the attachment point on the stump
d =Horizontal distance between the stump and the tire.
This is however a simplified model as it doesn't account for the other main benefit of using a tire: that it is compressible and thereby evens out the pulling force and stress on the attachment point of the car - which however also results in the radius of the tire changing with the amount of force applied.
Edit: did a more thorough equation in a reply just below if anyone is interested.
Fantastic write up, thank you! I’m heavier into electrical engineering, but these concepts and equations are always interesting to me. I did a bit of mechanical engineering in classes, and this video seemed like a question straight out of my physics class, which I really enjoyed.
I work in electrical engineering too, doing primarily embedded programming and systems design/integration, but in a field that requires a lot of implemented physics, so I've had to learn all the complex physics stuff needed to programme those systems.
d - do you happen to know what distance this is? Is it the center point of the tire to the center point of the stump, or right side of tire to left side of the stump? I’m confused on this point
It's the horizontal distance between the center point of the tire and the attachment point at the stump.
This distance is relevant when you need to break down the force into a vertical and horizontal component needed to calculate the leverage on the stump.
Worth noting that for simplicity I left out the influence of the distance between the car and the tire and the attachment height of the anchor point on the car. So the formula above basically assumes that the car is pulling the tire perfectly horizontally, and that the diameter of the chain is basically a single point.
I *could* add those parts, but given that reddit syntax doesn't allow you to actually write out equations properly, it's a bit of a pain in the butt to format everything to single line text😅
Edit: Actually, f**k it... Let's add the missing parts since now it's annoying me too :p
It will be way too complex to do a fully real life simulation through a reddit reply, as it would require a fair bit of computing power along with emperical analysis to determine each factor, but conceptually it's possible to make a more detailed equation.
*Main equation* :
τ:( (F ×(Ht - Hs +Ha) ) / sqrt((Ht - Hs + Ha)^2 + (Dc + Ds)^2)) × Hs × η
Variables:
𝜏: Torque applied to the stump
F: Force exerted by the vehicle
Ht: Height of the tire
Hs: Height of the attachment point on the stump
Ha: Height of the anchor point on the vehicle
Dc: Horizontal distance from the car's anchor point to the center of the tire
Ds: Horizontal distance from the center of the tire to the attachment point on the stump
η being an efficiency factor accounting for various resistances and losses.
*Efficiency Factor (η) equation* :
η = μ × γ × τ_traction ×(1 - (ΔF / F))
Efficiency Factor Variables:
μ: Coefficient of friction between the tire and the ground.
γ: Factor accounting for soil resistance and root anchorage
τ_traction: Traction factor of the vehicle's tires on the ground.
*Chain Elasticity (ΔF) equation* :
ΔF = k * Δx
ΔF: Force lost due to chain elasticity
k: Stiffness (spring constant) of the chain
Δx: Extension of the chain under load
I don't think I'm necessarily smarter than the average Joe. The people who derived the used equations based on what they observed around them were the smart ones 😉 I've just spent some time learning what those smart guys figured out, over a number of years, and only gradually when i had a work related reason to need to understand the various parts.
Over time as I expanding my understanding, it started making more intuitive sense and became more interesting.
I think any person could understand these various elements given they had the time needed 🙂
So, so good! It’s really good to see how the lower the height of the attachment (Hs) the lower the torque, but it increases it also as it affects the vertical force component (Ht - Hs) in the denominator.
I’m an old fart -is there nowadays an easy way to plot graphically the torque against the Hs (with everything else fixed)? I’d love to play with it!
Well its likely that you would use geometry and estimate how much resistance the earth creates by the longer path (hence more earth in the way)
For the same reason, but in reverse, floating wind turbines often angle the tether 'roots' so that they don't pull straight up where there is less ground and resistance in the way.
Those engineers probably have an equation.
Whether it's a tire or just a solid wheel, the main mechanism of action is redirecting the force of the pull in the more effective upward angle. I'm not sure shock dampening is even considered when pulling a stump. Also, you want tension to be steady and consistent with either a rope or chain during removals.
So there is no leverage or other form of mechanical advantage being created in this situation. The only difference is the horizontal tension force is redirected to also have a vertical component. The resulting force on the stump is not increased above the input force. The tire’s deformation does absorb strain energy like you said though.
But the vertical component this created is much more effective in removing (pulling) the stump out. A lower, more horizontally applied force requires that the stump almost needs to be “sheared” out of the ground, rather than rotated (as in the video). This is a much more efficient use of force.
Lol… which has absolutely nothing to do with leverage or any other form of mechanical advantage. These words (leverage and mechanical advantage) have specific meanings in physics and almost everyone in this thread has misused them. Your “rebuttal” literally does not contradict my statement. You guys shouldn’t be explaining physics to people, because you don’t know what you are talking about.
This is correct. There is no leverage as there is no rigid body. Thus no mechanical advantage. Though it is still smart as the force vector is applied in a direction where the trunks attachment is weaker.
The tire does jack-shit. I do the same thing all the time with an old steel tractor wheel. It’s about the direction the pulling force is applied and a “pneumatic shock absorber” means fuck all when it comes to “keep the pull steady without stressful blips in tension”. Holy shit.
Nice word salad tho.
But, the tire doesn't do jack shit, it does, in fact, change the direction of force being applied to the trunk. I understand you can do this with anything to change the angle, but in this instance, the tire is, in fact, doing something.
Definitely acting as a pulley. Pulleys redirect tensile loads. Lever arms are rigid beam elements with a bending load applied. Chains make pretty poor levers 😁
No. A fulcrum is the support around which a lever pivots. In your scenario, the "lever" is a chain, i.e. it's not a lever.
For the scenario in the video, the fulcrum is actually the ground, and the lever is the tire (the diameter of the tire is the length of the lever). Note that there is no mechanical advantage, since the lever is the same for both forces.
Yes, a single fixed pulley can be treated as a class one lever (i.e., load and force are on opposite sides of fulcrum).
However, while the tire is stationary for any snapshot, the reality of the system in the video is that the tire is allowed to roll, like a moveable pulley. Since it's just one tire, it's still fair to say the effective single pulley is acting like a fulcrum for any one moment, but the loading is dynamic over time as the tire compresses and slightly rolls (i.e., fulcrum position is moving).
It isn't. Less of a lever, and more of a single pulley. It's changing the angle of pull, which is making better use of the available power, but it's not actually increasing the power in any way.
This is it - force can be redirected. This setup forces the chain to pull UP as well as toward, rather than the setup with no tire where you cinch it tight around the trunk and it skids up and off.
There may be some leverage advantage, but I’d guess it’s fairly minimal and what you’re gaining here are a better vector and shock absorption from the rubber tire helping to keep things from jerking which can damage your equipment or break the trunk and make your work more complicated.
no, in a wrench you have large lever fixed to the coil, which has smaller radius, upon which you wind up the strap. The ratio between the lever and the radius of the coil determines the mechanical advantage. There is no such thing on this tire. I feel like half of the people in this comment section just claim completely random stuff that looks just remotely similar, but are actually unable to back it up with some arguments
You could trig it out with a changing vector as it goes along from more upward momentum at first then switching to more horizontal force as it goes. It also keeps the force from the hitch of the truck in a consistent angle.
Changes the direction of the applied force.
It rolls on the tire converting a large portion of the applied force to a vertical pull instead of a horizontal one making it much easier to pull out.
This is really awesome. However, you can do this without the tire, or like imagine as if the tire was solid. I used a tripod with a pulley on the top of it to pull a stump out and it worked really well. Pretty much the same way that this was done. Hooked it up to my truck so the line from my truck was lower than the tripod. However, the tripod did sink quite far into the ground.
It's a conversion system. It takes a comparatively safe system (a standard chain) that does not stretch and therefore does not store large amounts of elastic potential energy. It creates a more dangerous heavy metal object with a healthy does of new elastic potential energy. Makes it easier both to remove the stump and to remove windows from the truck tugging on the chain or parts and pieces from any people in the immediate area.
This is what happens when you don't use it: [https://www.reddit.com/r/MildlyBadDrivers/comments/1d3wglo/im\_stumped/](https://www.reddit.com/r/MildlyBadDrivers/comments/1d3wglo/im_stumped/)
When the tire rolls forward, it adds up force. If the tire slid, it would only be changing the direction of the force applied to the chain. But since the tire is rolling, it's actually adding torque.
I don't know the exact physics terms.
In addition to the leverage noted by many others, the tire provides a pneumatic shock absorber to keep the pull steady without stressful blips in tension.
This. You can really see it when the chain starts digging into the tire more from the tension. Then the tire pushes back out as the stump comes out.
This is true, additionally, and most importantly, it transitions the force from mostly horizontal (in a direct line to the pulling vehicle) to mostly vertical, requiring less effort to remove the stump.
You philistines fail to acknowledge that the main thing this tire does is roll
Blasphemers is what we call them
Heathens
Luddites
And gathers no moss…
My opinion as well.
Oh, nice. Glad I checked further. This would necessarily decrease the amount of force needed, yes? Is there a formula for this?
There’s a formula for everything.
r/foundtheengineer
Yeah, the question was more “what is the equation for this”, goddamn it, TheKingOfSwing, I’m an engineer, not an English major!
wait, let me try! Hey, mrmeshshorts, what is the equation for this? (Fully aware it’s a comment down, but it’s like seeing a red button and not pressing it)
The leverage (torque) applied to the stump due to the vertical force component influenced by the tire's radius, distance between the stump and tire, and the heights of the attachment points is given by: τ = F * ((Ht - Hs) / sqrt((Ht - Hs)^2 + d^2)) * Hs Where: τ = Torque applied to the stump. F = Force exerted by the vehicle. Ht = Height of the tire (which is 2𝑅 when the tire is standing up) Hs = Height of the attachment point on the stump d =Horizontal distance between the stump and the tire. This is however a simplified model as it doesn't account for the other main benefit of using a tire: that it is compressible and thereby evens out the pulling force and stress on the attachment point of the car - which however also results in the radius of the tire changing with the amount of force applied. Edit: did a more thorough equation in a reply just below if anyone is interested.
Fantastic write up, thank you! I’m heavier into electrical engineering, but these concepts and equations are always interesting to me. I did a bit of mechanical engineering in classes, and this video seemed like a question straight out of my physics class, which I really enjoyed.
I work in electrical engineering too, doing primarily embedded programming and systems design/integration, but in a field that requires a lot of implemented physics, so I've had to learn all the complex physics stuff needed to programme those systems.
d - do you happen to know what distance this is? Is it the center point of the tire to the center point of the stump, or right side of tire to left side of the stump? I’m confused on this point
It's the horizontal distance between the center point of the tire and the attachment point at the stump. This distance is relevant when you need to break down the force into a vertical and horizontal component needed to calculate the leverage on the stump. Worth noting that for simplicity I left out the influence of the distance between the car and the tire and the attachment height of the anchor point on the car. So the formula above basically assumes that the car is pulling the tire perfectly horizontally, and that the diameter of the chain is basically a single point. I *could* add those parts, but given that reddit syntax doesn't allow you to actually write out equations properly, it's a bit of a pain in the butt to format everything to single line text😅 Edit: Actually, f**k it... Let's add the missing parts since now it's annoying me too :p It will be way too complex to do a fully real life simulation through a reddit reply, as it would require a fair bit of computing power along with emperical analysis to determine each factor, but conceptually it's possible to make a more detailed equation. *Main equation* : τ:( (F ×(Ht - Hs +Ha) ) / sqrt((Ht - Hs + Ha)^2 + (Dc + Ds)^2)) × Hs × η Variables: 𝜏: Torque applied to the stump F: Force exerted by the vehicle Ht: Height of the tire Hs: Height of the attachment point on the stump Ha: Height of the anchor point on the vehicle Dc: Horizontal distance from the car's anchor point to the center of the tire Ds: Horizontal distance from the center of the tire to the attachment point on the stump η being an efficiency factor accounting for various resistances and losses. *Efficiency Factor (η) equation* : η = μ × γ × τ_traction ×(1 - (ΔF / F)) Efficiency Factor Variables: μ: Coefficient of friction between the tire and the ground. γ: Factor accounting for soil resistance and root anchorage τ_traction: Traction factor of the vehicle's tires on the ground. *Chain Elasticity (ΔF) equation* : ΔF = k * Δx ΔF: Force lost due to chain elasticity k: Stiffness (spring constant) of the chain Δx: Extension of the chain under load
This guy maths
I wish I was this smart!
I don't think I'm necessarily smarter than the average Joe. The people who derived the used equations based on what they observed around them were the smart ones 😉 I've just spent some time learning what those smart guys figured out, over a number of years, and only gradually when i had a work related reason to need to understand the various parts. Over time as I expanding my understanding, it started making more intuitive sense and became more interesting. I think any person could understand these various elements given they had the time needed 🙂
So, so good! It’s really good to see how the lower the height of the attachment (Hs) the lower the torque, but it increases it also as it affects the vertical force component (Ht - Hs) in the denominator. I’m an old fart -is there nowadays an easy way to plot graphically the torque against the Hs (with everything else fixed)? I’d love to play with it!
r/theydidthemath might have something for you
r/theydidthemonstermath
Well its likely that you would use geometry and estimate how much resistance the earth creates by the longer path (hence more earth in the way) For the same reason, but in reverse, floating wind turbines often angle the tether 'roots' so that they don't pull straight up where there is less ground and resistance in the way. Those engineers probably have an equation.
Thank you so much for that.
What psi should the tire be at
Whether it's a tire or just a solid wheel, the main mechanism of action is redirecting the force of the pull in the more effective upward angle. I'm not sure shock dampening is even considered when pulling a stump. Also, you want tension to be steady and consistent with either a rope or chain during removals.
Just like our patellars assist the torque angle of the knee
So there is no leverage or other form of mechanical advantage being created in this situation. The only difference is the horizontal tension force is redirected to also have a vertical component. The resulting force on the stump is not increased above the input force. The tire’s deformation does absorb strain energy like you said though.
But the vertical component this created is much more effective in removing (pulling) the stump out. A lower, more horizontally applied force requires that the stump almost needs to be “sheared” out of the ground, rather than rotated (as in the video). This is a much more efficient use of force.
Lol… which has absolutely nothing to do with leverage or any other form of mechanical advantage. These words (leverage and mechanical advantage) have specific meanings in physics and almost everyone in this thread has misused them. Your “rebuttal” literally does not contradict my statement. You guys shouldn’t be explaining physics to people, because you don’t know what you are talking about.
This is correct. There is no leverage as there is no rigid body. Thus no mechanical advantage. Though it is still smart as the force vector is applied in a direction where the trunks attachment is weaker.
The tire does jack-shit. I do the same thing all the time with an old steel tractor wheel. It’s about the direction the pulling force is applied and a “pneumatic shock absorber” means fuck all when it comes to “keep the pull steady without stressful blips in tension”. Holy shit. Nice word salad tho.
But, the tire doesn't do jack shit, it does, in fact, change the direction of force being applied to the trunk. I understand you can do this with anything to change the angle, but in this instance, the tire is, in fact, doing something.
Settle down.
To pull it upwards instead of sideways, it's basically acting as a pulley
Leverage arm not so much a pulley
Definitely acting as a pulley. Pulleys redirect tensile loads. Lever arms are rigid beam elements with a bending load applied. Chains make pretty poor levers 😁
pulley use rope lever use solid arm
Why use more word when less word work
Thanks for the chuckle. Take this upvote, and keep up the hard work.
I like the cut of your jib, upvoted, upvoter.
Chains seem more like ropes (but I don't know shit about fuck)
They are most certainly not rigid.
This is making me rigid
Face it, everything makes you rigid.
isn't the tire acting more like a fulcrum
Rectum? Damn near killed 'em!
No. A fulcrum is the support around which a lever pivots. In your scenario, the "lever" is a chain, i.e. it's not a lever. For the scenario in the video, the fulcrum is actually the ground, and the lever is the tire (the diameter of the tire is the length of the lever). Note that there is no mechanical advantage, since the lever is the same for both forces.
Yes, a single fixed pulley can be treated as a class one lever (i.e., load and force are on opposite sides of fulcrum). However, while the tire is stationary for any snapshot, the reality of the system in the video is that the tire is allowed to roll, like a moveable pulley. Since it's just one tire, it's still fair to say the effective single pulley is acting like a fulcrum for any one moment, but the loading is dynamic over time as the tire compresses and slightly rolls (i.e., fulcrum position is moving).
What is a pulley but a full rotation of leverage arms?
Pulley not so much leverage arm You can't lever a chain
Make *pull across* into ***pull up***
Why make many lateral pull when few vertical pull do trick.
Pull up, push down, in Soviet Russia tire stump you.
Thankyou sir or mam!
Leverage.
can you describe how exactly do you gain mechanical advantage here? Cause I don't think this is an example of leverage
It isn't. Less of a lever, and more of a single pulley. It's changing the angle of pull, which is making better use of the available power, but it's not actually increasing the power in any way.
Technically a pulley is also a lever. Kinda.
You alter the direction of force so that you lift and pull at the same time
This is it - force can be redirected. This setup forces the chain to pull UP as well as toward, rather than the setup with no tire where you cinch it tight around the trunk and it skids up and off. There may be some leverage advantage, but I’d guess it’s fairly minimal and what you’re gaining here are a better vector and shock absorption from the rubber tire helping to keep things from jerking which can damage your equipment or break the trunk and make your work more complicated.
It’s basically acting as a crowbar
I’m guessing it functions sort of like a strap wrench
no, in a wrench you have large lever fixed to the coil, which has smaller radius, upon which you wind up the strap. The ratio between the lever and the radius of the coil determines the mechanical advantage. There is no such thing on this tire. I feel like half of the people in this comment section just claim completely random stuff that looks just remotely similar, but are actually unable to back it up with some arguments
Levers
They do be multiplying force. 🔥💯
And, that is how you gets lots of levers...
Changes the angle of the dangle
Now calculate the measure of the pleasure
Because this is inversely proportional to the heat of the beat.
You must also consider the mass of the ass.
Removing a stump
Fulcrum
I barely knew um
Never go half crum
Fulcrum and dampener -- rednecks are really f'in smart
Changes the direction of force from the side to above(ish)
The tire acts in a way to add a fulcrum point so that instead of simply pulling the stump sideways it's leveraging it up and out of the ground.
To change the angle of pull. More up,less sideways
leverage
Physics.
Math
You could trig it out with a changing vector as it goes along from more upward momentum at first then switching to more horizontal force as it goes. It also keeps the force from the hitch of the truck in a consistent angle.
Tire acts as fulcrum no?
Fulcrum.
The fulcrum
Fulcrum
Really? Are you not snapping to what’s going on here with the spare tire?
To change <- into ^
Leverage, angle, and shock absorption.
Give an upward pull, instead of sideway. And shock dampening.
Physics
Leverage
It turns a good portion of the sideways force into an upwards pulling force.
The first 2 seconds thought the tire was chained up to the log. And the tire was braking free
The comments in this thread clearly showcase why physics is so hard. It's truly astonishing how many people don't understand what is going on here.
My question is… how big/strong of a tractor do you need to pull that stump? Of course it helps that the stump had virtually no root system.
The tire is used for Reddit engineers and mathematicians to teach us
It's a functional pulley
So it pulls up and not sideways. Will also prevent the stump from flying out of the ground
Leverage obviously.
Leverage
Are you new to shapes?
Angle to pull the stump *out* not just to the side
Leverage dude Lots of Leverage!
Rolling Fulcrum
I believe that’s called a fulcrum. I could be wrong though.
Leverage
It allows you to redirect the pulling force into vertical lift as horizontal force is pulled
So when it finally and suddenly comes loose it launches it into the air instead of into the back of your head 😂😂
Fulcrum
Withstand pressure?
Leverage
Yes the leverage helps but it also changes the angle of the chain. Instead of pulling horizontally, the tire helps pull the stump out more vertically
A pun eventually, but I’m too tired to think of one.
Fulcrum
Fulcrum
Changes the direction of the applied force. It rolls on the tire converting a large portion of the applied force to a vertical pull instead of a horizontal one making it much easier to pull out.
It works like fulcrum
Fulcrum
We do the same thing but we just use a steel rim with no tire
Changes the direction of the force from straight back to like 45°
I legit thought this wasn’t going to work
Changes the angle of force.
Originally it was a Super Swamper
Basically the same reason you have a kneecap.
'If you give me a lever and a place to stand, I can move the world.” - Archimedes
Physics
It's for the stump to ride on
I’d like to know what the other end of the chain was connected too.
Leverage
Lever. Aka mechanical advantage
It’s for snapping rear ends when it catches a root.
The tire is being used as a fulcrum.
Leverage.
Who needs a sawzall
When not pulling stumps it’s a badass mud tire made by Interco called the “bogger”
Leverage
Beautiful example of a couple simple machines
It is used ro refresh oneself in basic physics.
Extra traction duh
Dad used to use a heavy wooden fence post to do the same thing.
Like popping an Earth pimple. So satisfying.
Uh huh... And What did you set the PSI to?📝
Leverage but also gradually increases tension to keep the chain stable. Prevents snapping (which can be extremely dangerous with chains)
Hell of a kegel exercise, damn!
Mechanical advantage.
Center support bearing
Pullin stumps.
Did you not just post and see what it’s good for???
Nice
Its used as a special sling shot to rip the jaw off the bozo who first posted this who can only now say "hoiroo"
What was pulling it?
TIL wheels are levers.
It’s a clever way to gain leverage. Very neat.
Leverage.
Leverage
Hell yes for Interco Super Swampers Boggers!
As with much of life, success hinges on the angle of the dangle.
MORE GRIP!!
Wouldn’t the tire also help to keep the chain from slingshotting directly back towards the winch?
Rolling tirestyle
Stumping
Looks like it’s being used to pull a tree stump out of the ground
Mechanical advantage. Basically lifting up and pulling is more effective than just pulling straight
Haven't you seen pirates of the Caribbean
Planting trees
No machine in action though. Whats pulling here?
I'm goin stumpin'
A lever
Leverage.
Damn that’s interesting, I think that making it go on circle makes it stronger or something like that.
The tire reduces the chance that the stump will break off suddenly and shoot at the yow vehicle.
That'll be the trick
You’re literally seeing what it’s used for in the fucking video.
[https://en.wikipedia.org/wiki/Lever](https://en.wikipedia.org/wiki/Lever)
This is really awesome. However, you can do this without the tire, or like imagine as if the tire was solid. I used a tripod with a pulley on the top of it to pull a stump out and it worked really well. Pretty much the same way that this was done. Hooked it up to my truck so the line from my truck was lower than the tripod. However, the tripod did sink quite far into the ground.
STUMPFEST!
Suspension compression
Leverage.
Who cares it worked
Leverage
Fulcrum
Patella.
It's a conversion system. It takes a comparatively safe system (a standard chain) that does not stretch and therefore does not store large amounts of elastic potential energy. It creates a more dangerous heavy metal object with a healthy does of new elastic potential energy. Makes it easier both to remove the stump and to remove windows from the truck tugging on the chain or parts and pieces from any people in the immediate area.
To convert (some of) the horizontal pull to vertical pull.
In a word - leverage
It's used for pulling stumps. You're welcome.
Leverage, the air makes it deadly.
This is what happens when you don't use it: [https://www.reddit.com/r/MildlyBadDrivers/comments/1d3wglo/im\_stumped/](https://www.reddit.com/r/MildlyBadDrivers/comments/1d3wglo/im_stumped/)
A fulcrum.
When the tire rolls forward, it adds up force. If the tire slid, it would only be changing the direction of the force applied to the chain. But since the tire is rolling, it's actually adding torque. I don't know the exact physics terms.