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Modding Project : Mini trebuchet

Discussion in 'Modding' started by woof82, 15 Jul 2007.

  1. woof82

    woof82 New Member

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    dacust, sounds like you know what you're talking about :) I was considering using wheels, but this is just a small trebuchet, so I think that they wouldn't make much difference and could cost quite a bit to add.

    I want to see more people building trebuchets! We could have a competition - maybe a paypal prize to the winner :p
     
  2. dacust

    dacust What's a Dremel?

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    Just suspend the weight. That actually works better than wheels. And you can do it cheap.
     
  3. woof82

    woof82 New Member

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    After a little extra filing, it fits snugly! I screwed the two halves of the block together, and screwed the two halves of the axle onto the bock, so that they wouldn't slide out. The thinner rod is the throwing arm, and it runs all the way through the block, the thicker white painted rod is the axle, and it is cut in half, so it doesn't go all the way through the block, but I screwed it in position to prevent it from sliding out:
    [​IMG]
     
  4. Spacecowboy92

    Spacecowboy92 Gettin' Lazy

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    Im starting building mine on Friday when School breaks up. Then its only about 40 mins to Oxford from Winchester, do you think they'll let me on the park and ride with a Trebuchet?
     
  5. woof82

    woof82 New Member

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    Hah, possibly not, I kind of meant post pictures and measure launch distance and weight of projectile etc.

    That way I'm less humiliated when mine doesn't work :p
     
  6. Spacecowboy92

    Spacecowboy92 Gettin' Lazy

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    Don’t worry :lol: I wont really show up on your door step with siege weaponry
     
  7. zhangmaster12

    zhangmaster12 New Member

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    @dacust: somebody did his homework and has developed quite an intimate relationship with trebuchets. LOL jk.
     
  8. dacust

    dacust What's a Dremel?

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    Hey, I know I'm strange. And I'm OK with that.:D

    I've always liked old weaponry. A Christmas or two ago my brother gave me a book on catapults (a trebuchet is just an advanced catapult design). It actually taught me very little I didn't already know about the designs and workings, but I learned a lot about the history.

    I can't find the book right now, so I can't quote, but here is something it said (imperfect from memory).

    Last successful us of a trabuchet - 17?? - and it goes on to describe the encounter.
    Last unsuccessful use of a trebuchet - 18?? - and it goes on to describe how in Mexico during a siege, a soldier convinced the commander that he could build a trebuchet to batter down the town walls. He built it. The first shot went straight up in the air, came down and destroyed the machine. The commander refused permission for building a second one.

    Remember, for silly, useless, arcane information, ask dacust. If you want information on a particular subject, I may not know anything, (after all, if you ask for it, it may be useful, duh!) but I guarantee you I can find an inventive way to go off on a tangent and tell you something silly and useless on a totally different subject.
     
  9. woof82

    woof82 New Member

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    I bought a high tenstion steel cable kit from homebase:
    [​IMG]
    [​IMG]





    And started attatching it to the end of the arm:
    [​IMG]





    Ok, now just for testing purposes I've come up with a quick way that I can add weights and change weights until I find the ammount that will work best - I basically just zip-tied a block of wood to some dumbells then attatched the other end of the high tension steel cable to the wooden block using the dongle:
    [​IMG]

    [​IMG]




    Before I can add this to the trubuchet I need some kind of release mechanism, so I can hold the firing arm down before I want to fire, then let it go while remaining at a safe distance -

    I put two eyelets into a plank underneath where the firing arm would rest before firing:
    [​IMG]


    And I found this, which I added some string to:
    [​IMG]

    So now you see I can just staple some string onto the firing arm, then tie a loop the end of that string and hook it onto that peice of metal near the ground as it sits resting between the two eyelets, and when I want to fire, I just tug on the rope attached to that peice of metal. I didn't get a picture of it all together but I think you get the idea.

    This is the release mechanism:
    [​IMG]

    This is the string attatched to the firing arm:
    [​IMG]





    [​IMG]



    Ok next up is another trickey bit - making the sling for the projectile.
     
    Last edited: 19 Jul 2007
  10. dacust

    dacust What's a Dremel?

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    Oh, yeah. It's coming together. I'm thinking you may get good performance out of that without too much tinkering. I LOVE seeing someone do a good job cheap.
     
  11. fri2219

    fri2219 New Member

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    Just out of curiosity, what are you doing to ensure no one gets killed firing your weapon?

    I'd predict that the wood components in particular will fail catastrophically after a few cycles of tension and release. Also, a broken cable under high tension could easily decapitate someone, or tear open an artery- bleeding to death in 30 seconds is not the way most people plan on ending their lives.

    In another life, I used to construct things like this all the time, and catastrophic failures were not unknown. After a while, I avoided using materials that splintered or tore on failure.

    As a result, most of my failures involved experimental payloads, like rotten onions encased in frozen (also rotten) butter. (eeeeeeew!)
     
    Last edited: 19 Jul 2007
  12. woof82

    woof82 New Member

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    Umm... maybe you didn't look at that picture, but the wire is only 4 inches long, and the barbells only weight 10lbs... You would actually have to lie underneath it and hope they slid off and hit you in the face to even receive significant injury. I'm going to say beyond all reasonable doubt that death is not a concern with this device.
     
  13. THEkorean

    THEkorean 42

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    Wow! thats pretty awesome, i remember i built a mini (really mini, like.. 2 foot tall) trebuchet for my physics class a while back, it was pretty cool, but not half as good as yours. Good luck on your project!

    I found a picture!
    [​IMG]
     
  14. jakenbake

    jakenbake full duplex

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    Note to self: never get in a trebuchet fight with dacust

    nice random build, i love it. keep us updated.

    Oh, and if there aren't pictures of your cat flying thru the air then i will be severely disappointed.
     
  15. Morphine-Kitty

    Morphine-Kitty Dead account.

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    As will I. He shouldn't mind. I mean, at least you're shooting him out of a mini trebuchet.
     
  16. woof82

    woof82 New Member

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    Ok here we go!


    This is the sling I made, I just found a bit of netting, which I got to fit around the ball by tieing string in places around it (like the bit you can see at the back of the ball in the picture):

    [​IMG]


    I tested this, and the ball kept rolling out. So I shortened the string the connects to the arm by about 5ft, and I tied the string onto the pouch lower down, and I tightened the string around the ball so it would fit more snugly into the pouch:

    [​IMG]

    [​IMG]


    Ready to fire!

    [​IMG]
     
  17. woof82

    woof82 New Member

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    See the red circle in this picture? That's our garage...


    [​IMG]




    The first time I fired this (after adjusting the pouch...) it hit the roof of the garage. The second time I fired... it hit almost exactly the same spot - I was impressed with the consistancy! The third time I fired it cleared straight over the garage into our neighbour's garden! :D
     
  18. capnPedro

    capnPedro Hacker. Maker. Engineer.

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    We need videos!
     
  19. dacust

    dacust What's a Dremel?

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    Success!!! Cool! I second the video request!
     
  20. woof82

    woof82 New Member

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    Have you seen the weather outisde?

    I had to dismantle it because it's not treated :waah:

    If the rain stops for long enough over the weekend then I'll try get a video....
     

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