General > General Technical Chat
Force multiplier
electrodacus:
--- Quote from: cbutlera on February 09, 2023, 08:58:38 pm ---
I don't need to build a pantograph out of cardboard. I have a real one, I have used it, and it works just as shown on the Wikipedia page.
--- End quote ---
I have not asked you to build a pantograph but the mechanism in my diagram as that one will not move unless it slides as a solid piece.
--- Quote from: cbutlera on February 09, 2023, 08:58:38 pm ---You seem to have taken on the mission of teaching the world how to understand Newton's third law. Well teach me! Please answer my question. Why does your version of Newton's third law make the articulated table behave as a rigid object, but not the pantograph?
--- End quote ---
It depends on where the articulations are
Do you feel like this look the same ?
Remove one articulation so that pantograph looks like letter A then you will see that there is no longer andy independent movement same as there is no movement on the mechanism in discussion.
You think it will move because you imagine pushing on the green part (vehicle body) but that is not allowed as vehicle body is floating and nothing pushes against that the F5 = F6 so there is zero net force acting against the body.
There must be some brain difference that do not allow some people to imagine what happens when forces are applied on an object else I can not explain why it is not obvious that F1 = F2 and in order to move the mechanism needs to slide as shown in my video.
Even seeing the video with the locked mechanism being slide in the same direction as applied force is no proof for you so you either want to blame that on something else or you think I faked the video.
electrodacus:
It seems we are circling back to same questions.
I provided the proof that mechanism is locked so F2 = F1 at constant speed and it moves in the same direction as applied force
first 15 seconds in this video https://odysee.com/@dacustemp:8/stick-slip-removed-from-front-wheels:0
Also showed what happens if input wheel (right wheel) is allowed to slip
https://odysee.com/@dacustemp:8/wheel-cart-energy-storage-slow:8
Unless you think I faked any of this videos no other proof is needed for my claim. And if you think it is faked it is on you to show the same setup working differently and that will disprove my theory unless you fake the video :)
Also your claim that vehicle should work because of gear ratio that allows F2 to be multiple times of F1 requires 3 points of contact and there are only two.
If you think force multiplication can be done with only two points of contact then you need to provide a link to a commercially available torque multiplier wrench that works with just two contact points and that will be proof enough for me.
cbutlera:
--- Quote from: electrodacus on February 09, 2023, 09:37:56 pm ---...
Do you feel like this look the same ?
--- End quote ---
No, one is an animation and the other is a static image, but to me that is not convincing proof that one is a rigid structure and the other isn't. But other than that, yes they look very similar, both are hinged quadrilaterals with extended edges.
--- Quote ---Remove one articulation so that pantograph looks like letter A then you will see that there is no longer andy independent movement same as there is no movement on the mechanism in discussion.
You think it will move because you imagine pushing on the green part (vehicle body) but that is not allowed as vehicle body is floating and nothing pushes against that the F5 = F6 so there is zero net force acting against the body.
--- End quote ---
Both the pantograph and the articulated table are made up of 4 struts in the form of a quadrilateral with extended edges and with the with hinge joints where they intersect. Such shapes do not form a rigid structure.
If I remove one strut from either of them, then they both form triangles with extended edges, with hinge joints where they intersect. Such triangles do indeed form a rigid structure. But I don’t see how that differentiates the two cases.
The pantograph and the articulated table are both only supported at two points. In both cases the mechanism in-between is floating. So I still don’t understand what the key difference is that makes one of them behave as a rigid structure, and not the other.
--- Quote ---There must be some brain difference that do not allow some people to imagine what happens when forces are applied on an object else I can not explain why it is not obvious that F1 = F2 and in order to move the mechanism needs to slide as shown in my video.
--- End quote ---
You claim that it is obvious and say that you can imagine it, but you can't actually explain it in plain language. I'm afraid that plain language and mathematics is the only thing that I understand. Plain language and mathematics explanations served me well at university when I was studying for my physics degree. They served me when I was studying classical mechanics, special relativity, thermodynamics, statistical mechanics, electromagnetism, optics, solid state physics, quantum mechanics, electronics, etc. But somehow plain language and mathematics is not sufficient to explain Newton's third law to me, which for the last 50 years I thought that I understood.
Can you tell me, what is it about Newton's third law that makes it so very hard to understand?
electrodacus:
--- Quote from: cbutlera on February 09, 2023, 11:20:25 pm ---You claim that it is obvious and say that you can imagine it, but you can't actually explain it in plain language. I'm afraid that plain language and mathematics is the only thing that I understand. Plain language and mathematics explanations served me well at university when I was studying for my physics degree. They served me when I was studying classical mechanics, special relativity, thermodynamics, statistical mechanics, electromagnetism, optics, solid state physics, quantum mechanics, electronics, etc. But somehow plain language and mathematics is not sufficient to explain Newton's third law to me, which for the last 50 years I thought that I understood.
Can you tell me, what is it about Newton's third law that makes it so very hard to understand?
--- End quote ---
I did better than just explain in plain language. I showed you a video of the real device being locked and dragged in the direction of applied force.
While the mechanism can move it will not move when F1 is applied as shown in the diagram. If force was applied to some other parts of that mechanism then movement is possible but that is not relevant for the current problem where mechanisms is locked and demonstrated in a real experiment.
If you connect the vehicle body to ground then you will have the F1 applied between the vehicle body and input wheel and for a 2:1 gear ratio you will have F2 between the output wheel and vehicle body equal with 2 * F1 so what you will consider a functional gearbox.
But as soon as you remove the vehicle body from ground the body is now floating and there is no net force acting on it.
I do not think Newton's 3'rd law is hard to understand but it seems I'm proven wrong by all your comments.
In school manuals for Newton's 3'rd law you will see an example like the one below.
So my question is simple. Just add this device or any other device you want instead of the Force meter thus just two points of contact one on the string connecting the human say human pulls with F1 and the other point connecting the string that is connected to wall say that force will be F2
Can any device be able to take the input F1 and have the output F2 be different than F1 ?
Maybe pulling instead of pushing makes it more easy to understand and it is a typical example for Newton's 3'rd law.
Unless that magic box replacing the Force meter has a third point for leverage it will not be able to have F2 different from F1.
cbutlera:
--- Quote from: electrodacus on February 09, 2023, 11:40:54 pm ---I did better than just explain in plain language. I showed you a video of the real device being locked and dragged in the direction of applied force.
--- End quote ---
That video is a demonstration of something, but it is not an explanation of anything. Do you understand the difference between a demonstration and an explanation?
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