pins and bushings for folding wings

Discussion in 'Tips, Tutorials & Tools' started by lizzienewell, Jul 4, 2005.

  1. lizzienewell

    lizzienewell Member

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    I'm making a model of a science-fiction craft of my own design. The craft is a WIG aircraft designed with folding wings. WIG or shipwing crafts are consider marine crafts as far as regulation goes so this could fit in either ships or airplanes.

    I call my version of a WIG a skip. It differs from non-ficton shipwings by having folding wings, running off of hydrogen, and by being smaller and lighter wight. It would classify as an ultralight airplane. The propulsor jets works like sneezing squid. They give rythmic and controlable bursts of power. The hull and wings would be made of piezoelectric aramid fiber so that they can adjust shape for increased efficiency.

    So does my model go in the science fiction, ship, or airplane forum catagory? It could also classify as an animal model since I've based the design on puffin birds and on squid.

    My skip would carry three people only and would travel no faster than a Piper Cub. With foldable wings it can be righted if it flips over in the water. With the wings folded it can travel as a hydro foil. It would be used for fishing regulation and as a pilot craft to get pilots out to big ships.
    It would also be great fun especially for those who like to fish.

    In modeling it, I'm making the foldable wings and so need to make hinges. Does anyone have experience or suggestions about movable parts.

    Right now I'm using wire as the hinge pins but I'd like to use some sort of bushing so that the hinge in more durable.

    This may seem to be a departure from my tug and fishing boat interest but it's not. I'm creating a science-fiction world with a futuristic fishing technology.

    Here is a snippet from my manuscript regarding this type of craft.

    "In the failing light, aircraft approached only meters above the water. Searchlights lanced into the waves to locate survivors or flotsam for salvage. The Tulko had come for me.

    As the white light flashed over me, I ducked my bubble-clad head. Would they identify me as human?
    The flock settled around me, as silent as owls. From a floating craft, a lifeline glowed against the evening sky. With dread, I reached for the fluorescent rope in the dark water."

    Lizzie
  2. wunwinglow

    wunwinglow Active Member

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    Hi Lizzie,
    Plastruct make a terrific range of plastic tubes, channel, angle, tee sections in both ABS and polystyrene, and O am sure you will find some of the tubes will telescope inside each other. Have a look at their website www.plastruct.com Don't be put off by their weird catalogue listing, have a look via the alphabet listing buttons at the bottom of the product page. Either that, or order a printed catalogue! There should be a hobby shop near you that either stocks the stuff, or can get it for you, if you don't want to order direct.

    Tim P
  3. Sticky Fingers

    Sticky Fingers Member

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    Another option is to use either brass or Aluminum (OK, A-L-U-M-I-N-I-U-M) tubing from K&S. The tubing is engineered to be telescoped. In fact it can be used to make really nice landing gear struts for use on all media along with other cylindrical parts.

    http://www.ksmetals.com/Homepage/default.asp?Title=Products
  4. Bowdenja

    Bowdenja Active Member

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    Hey forget the hinge thing...........bring on some more of the writing. 8)

    Are you finshed with it or is it still under construction? The manuscript that is. :?

    Also show us the model. :D
  5. charliec

    charliec Active Member

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    If you want to stick to paper for your hinges may I offer some observations about trying to build paper mechanisms:

    Paper/card is very weak in shear, has high friction between two paper surfaces and probably won't stand much repetitive bending without failing.
    A conventional hinge with a small diameter pin isn't going to be very strong and will fail alongside the pin from the loads from opening/closing the hinge.

    About the only easy way to partially get around the weakness of paper is to increase the contact area so the loads are distributed over a larger area.

    My guess for a workable paper hinge would be to increase the size of the hinge pin so it becomes like two telescoped cylinders. However this is going to produce high friction between the cylinders. If the fit is reasonably tight so you'll have to come up with a method of lubricating the working surface. The size of the telescoped cylinders would have to be determined
    by experiment.

    At least with the cylinder concept it should be easier to attach the hinge to the rest of the model since you'll have a reasonably large attachment area.

    If interested, and/or my explanation is incomprehensible I can probably come up with some drawings.

    Regards,

    Charlie
  6. Maurice

    Maurice Member

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    Lizzie

    Even in the real world wigs are science fiction since they take inadequate account of the rules of wave formation. Every so often they will meet (and slam into) a larger wave than they can levitate over at the speed at which they are travelling. There a'int no future in that, as has been shown by their failure to catch on.
    You may need to amend the laws of physics as they apply on Fenria.
    I reckon they're surface vehicles since like hovercraft they are supported by interaction through a cushion of air with a "solid" surface and not solely by interaction with the atmosphere.
    Staying with paper for your hinges, pins can be made from thin paper wrapped around a hat pin or piece of fine music wire, remove the former and then soak in CA.
    Bushes by wrapping around something a little fatter then soaked.
    To fasten to the adjacent structure do what is done with "real" hinges and wrap the bushes wth a strip that is glued to the adjacent structure. Correctly aligned they are thoroughly durable. Can be lubricated with powdered graphite if you feel the need.
    (Otherwise you can buy plastic and metal hinges in various small sizes already made up.:D)
    Delightful boats BTW.

    Cheers
    Maurice
  7. Gil

    Gil Active Member

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  8. lizzienewell

    lizzienewell Member

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    Thank you all for the assistance. After trying to make paper hinges, I decided to use styrene and wire for the hing parts. It's working better. My experiements with paper hinges looks rather sad.
    I've posted a photo in my album.
  9. lizzienewell

    lizzienewell Member

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    manuscript

    bowdenja,

    I've got one manuscript done and another started. And a publisher requested to see them so I've writing synosis of both of them. She might not like either of them so I am remaining hopeful but not too excited.

    Lizzie
  10. lizzienewell

    lizzienewell Member

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    imposibility of WIG craft

    My solution is to put on foldable wings and plan that the craft will either catch a wing or endo. The pilot then can turn it right side up as if it were a kayak and go on. They might even do it deliberately for fun. I think it would be like skiing mogels.

    In my manuscript I show someone deliberately endoing one of these craft.

    If Herbert can use ornothopters then I should be fine with ekronoplans. I'm not bending the rules of physics as far as he did.

    Maurice wrote:

    Even in the real world wigs are science fiction since they take inadequate account of the rules of wave formation. Every so often they will meet (and slam into) a larger wave than they can levitate over at the speed at which they are travelling. There a'int no future in that, as has been shown by their failure to catch on.
    (Otherwise you can buy plastic and metal hinges in various small sizes already made up.)
    Delightful boats BTW.

    Cheers