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View Poll Results: if it starts like drawing on the left will gravity take it to the drawing on right?

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Thread: what do you think will happen on this meccano experiment?

  1. #1 what do you think will happen on this meccano experiment? 
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    im doing the experiment this friday when i get my mecanno but id like to see peoples opinion while i wait


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  3. #2  
    Forum Professor marcusclayman's Avatar
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    It helps to label parts A,B,C,D, etc, with a key for those of us who don't know technical terms of things but want to ask questions.

    I have no idea how this thing is supposed to work, if at all.


    Dick, be Frank.

    Ambiguity Kills.
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  4. #3  
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    here:



    i dont know what happens either thats why i ask but i see the cog lowers so i suppose gravity will make it go from left drawing to right drawing
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  5. #4  
    Forum Professor marcusclayman's Avatar
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    It doesn't seem that this is possible, not as it's described.

    The segment AB cannot rotate around the wheel as the section CD drops because for it to do so the contraption would need to shift first to the left, upward and then to the right(or the opposite direction)... but the only pressure is downward... the "x" piece is trying to become a "ll" piece, but in doing so it pushes inwards and up on the AB section, which will not make it revolve around the wheel
    Dick, be Frank.

    Ambiguity Kills.
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  6. #5  
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    here see how in this case ab rotates, quite similar both cases:

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  7. #6  
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    i couldnt wait came from the beach to my home city looking for my meccano and just did the experiment

    gravity takes the thing from state 1 to state 2

    in fact state 1 is an unstable balance
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  8. #7  
    Forum Professor marcusclayman's Avatar
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    interesting... can you take some pictures? I don't understand what this last drawing has to do with the first, and how the first can be possible.
    Dick, be Frank.

    Ambiguity Kills.
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  9. #8  
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    heres in an unstable balance thats why hold it:


    and here what it evolves to, im holding it to avoid torsion ruins the meachanism:
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  10. #9  
    Moderator Moderator Janus's Avatar
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    Take a look at this model made with Fantastic Contraption, it models the physics well. Just click the green "start" button.

    http://FantasticContraption.com/?designId=8689037

    The blue line that passes through the "weight" is for reference.

    Note that at the end the weight is lower than its original position. It is now at an equilibrium point.
    Also note that if the top section were to continue to rotate, it would have to lift the weight to a point above it's starting point. This would take more energy than the system started with.

    So even though the second drawing in the OP is at a lower energy state than the first, the device cannot, on its own, go from the first state to the second, as there is an "energy hump" in between the two.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  11. #10  
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    i just got that amazing game, check out how modifying slightly the design what i meant is posible:

    http://fantasticcontraption.com/?designId=8692145
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  12. #11  
    Moderator Moderator Janus's Avatar
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    Quote Originally Posted by luxtpm
    i just got that amazing game, check out how modifying slightly the design what i meant is posible:

    http://fantasticcontraption.com/?designId=8692145

    By making the upper part smaller, you removed the need for the COG of the system to raise above the starting point. But note that your final resting position is not like that in your original drawing. The system tilts. No matter how much you try to balance it out, it will end up tilted like this to one side or the other.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  13. #12  
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    i wouldnt trust this program that much:

    http://FantasticContraption.com/?designId=8693747
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  14. #13  
    Moderator Moderator Janus's Avatar
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    Of course the actual point of Fantastic Contraption is to design something that will get the red "target object" into the Goal area.

    As an extra challenge, you try to get the target to stay in the goal, such as this one that I came up with:

    http://FantasticContraption.com/?designId=632791

    You can also try to come up with a solution by using the fewest components:

    http://FantasticContraption.com/?designId=5136760
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  15. #14  
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    Quote Originally Posted by Janus
    Of course the actual point of Fantastic Contraption is to design something that will get the red "target object" into the Goal area.

    As an extra challenge, you try to get the target to stay in the goal, such as this one that I came up with:

    http://FantasticContraption.com/?designId=632791

    You can also try to come up with a solution by using the fewest components:

    http://FantasticContraption.com/?designId=5136760
    ?????

    When I go to that site all I see is some portal to a game of some kind and a bunch of cartoon characters.
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  16. #15  
    Moderator Moderator Janus's Avatar
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    Quote Originally Posted by DrRocket
    Quote Originally Posted by Janus
    Of course the actual point of Fantastic Contraption is to design something that will get the red "target object" into the Goal area.

    As an extra challenge, you try to get the target to stay in the goal, such as this one that I came up with:

    http://FantasticContraption.com/?designId=632791

    You can also try to come up with a solution by using the fewest components:

    http://FantasticContraption.com/?designId=5136760
    ?????

    When I go to that site all I see is some portal to a game of some kind and a bunch of cartoon characters.
    You usually have to wait a while for the actual game to load. You should see a bar at near the bottom with moving lines with "loading game" above it. After a while, the game should come up.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  17. #16  
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    check out my last design:
    http://fantasticcontraption.com/?designId=8700523
    do you think it would be cool to build? a box that rolls by itself?
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  18. #17  
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    Awesome program
    Wise men speak because they have something to say; Fools, because they have to say something.
    -Plato

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  19. #18  
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    http://FantasticContraption.com/?designId=8740221

    this is an awesome contraption!
    Wise men speak because they have something to say; Fools, because they have to say something.
    -Plato

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  20. #19  
    Moderator Moderator Janus's Avatar
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    Quote Originally Posted by Arcane_Mathematician
    http://FantasticContraption.com/?designId=8740221

    this is an awesome contraption!
    Your design?

    Here's a couple of my own:


    Solution for U-turn, with minimum parts and keeping it in the goal:
    http://FantasticContraption.com/?designId=806066

    Around the Bend using just 1 rod and keeping it in the Goal (you have to be patient for this one)
    http://FantasticContraption.com/?designId=722096

    A somewhat around-about solution to one of the bonus rounds.

    http://FantasticContraption.com/?designId=1667646
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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