Would this be possible?

Discussion in 'New project ideas' started by BoyntonStu, Dec 30, 2013.

  1. BoyntonStu

    BoyntonStu Member

    Imagine an Xbow with 40 pound limbs.

    My thinking. You were going to pull 40 lb with a rigid fork which itself feels the same 40 pounds but it is fixed.

    If you pull 40 pounds with flexible limbs, they feel the 40 pounds and they bend along with the rubber being stretched. When you release the rubber it is relaxing along with the limbs returning to their unflexed position.

    Will the extension of the rubber be the same in both cases?

    Certainly, if you could cock the limbs to 40 pounds, then draw the rubber to 40 pounds, you would have 80 pounds of potential energy.

    Can you think of a way of triggering both?
  2. JohnKrakatoa

    JohnKrakatoa Loudest boom on Earth

    the rubber will start to pullthe limbs only when it reaches its max elongation, my guess

    edit: i reread it so scratch the above.. i think it wouldnt add much
    Last edited: Dec 30, 2013

  3. kohlqez

    kohlqez Accident-Prone

    How about with a trigger? You just make it attached to 2 Sears instead of one
    It wouldn't be difficult to trigger them at the same time at all (if you have the proper materials) however you may find it difficult to make a 2 stage cocking mechanism (limbs then rubber).
    Also I don't think releasing at the same time would give you the effect you're looking for.
    Maybe if you make the limbs release a fraction of a second before the rubber you might get your 80lbs of draw weight which would require some serious engineering and probably math (eww), but if they're released at the same time you'd be wasting energy.
  4. WildBill

    WildBill The Silly Song Guy

    I think you're after something akin to 'perpetual motion'. If you combined the rubber with the flex limbs and drew it to 40lbs force, that's all you would have- 40 lbs. Both rubber and limbs would accept portions of the draw. If you wanted to get 80lbs of draw from them, you would have to draw them out with 80 lbs of force. To draw one and then the other, yes, you'd need a trigger for them, but it's likely to be an unstable method.

    -Wild Bill
  5. Obl1v1Aus

    Obl1v1Aus Meh!

    I dont think a divice like that will increase the poundage, realistically all your doing is increasing the length of draw, it would still be 40 pounds just with a two stage power stroke.
    And then your releases would have to be perfectly timed down to the micro second or you would lose all advantage of the setup.
  6. I agree, draw weight would most likely stay the same, however the extra acceleration of having two "power sources" will probably increase the travel speed of the projectile. Just a guess.
  7. ColtSmith

    ColtSmith New Member

    Tht would be cool if it works