Little help, please?

Discussion in 'Gallery & Designs' started by EricGoedkoop, Mar 4, 2006.

  1. EricGoedkoop

    EricGoedkoop Member

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    Can anyone help me out with a part that's been giving me way too much trouble?

    I've been (slowly) working on a scratchbuilt Grahame-White Type VII and cannot for the life of me figure out how to do the nacelle's upper forward deck. This is the aeroplane:

    [​IMG]

    And here's a side and top view I drew of the nacelle:

    [​IMG]

    For some reason, I just can't get a handle on the top of that nose. It's almost half a cone with depressed sides, but the semi-circular front of the nacelle screws everything up. I'm sure there's a way to figure out this shape that I'm just not thinking of - somebody lend me a hand?

    Much appreciated,

    Eric
  2. Maurice

    Maurice Member

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    You get to scale it to the size you want.

    Attached Files:

    • bit.pdf
      File size:
      1.7 KB
      Views:
      61
  3. nx13688

    nx13688 Member

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    Attached Files:

  4. Maurice

    Maurice Member

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    Ryan

    Yes that does allow for the sag in the fabric.

    Cheers
    Maurice
  5. Gil

    Gil Active Member

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    Yet another PDF file...,

    Kind of an interesting shape from a CAD point of view. Straight forward twin rail sweeps yielded some interesting results. I agree with Maurice it's a sort of hyperbolic function (weighted caternary system). Did a quick render of it covered in linen...,

    -Gil

    [​IMG]

    Attached Files:

  6. EricGoedkoop

    EricGoedkoop Member

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    Wow!

    Thanks, Gents. I'll play with these tommorrow and let you all know how it works out. Many thanks.

    As a side note, I've been wondering about the material used on the original - the shape indicates tightened fabric, but that seems an odd choice for the business end of the machine. As you can see, I went with metal in my drawings but if it had been metal there wouldn't have been any good reason for the complexity of the shape.

    Looks cooler, anyway.
  7. shrike

    shrike Guest

    99% chance that it's just a piece of lightly doped linen. Probably after the first flight a simple bent wood hoop and cloth panel was added as an afterthought to form a rudimentary windscreen.
  8. EricGoedkoop

    EricGoedkoop Member

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    Probably so.
  9. Gil

    Gil Active Member

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    Ever ride a motorcycle and get hit in the face by a bug, hail or rain at 40-60 mph? This is most probably the reason for the hurried addition.

    -Gil
  10. keith

    keith Member

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    Breathing aid perhaps?

    I've seen an australian hit by a blackbird on his motorcycle, he was wearing an open faced helment and didn't see the funny side at all!

    Thats one for the aviation fans, what was the first recorded incident of birdstrike?
  11. Texman

    Texman Guest

    The first recorded birdstrike was in Dayton, Ohio, in 1908, a plane being flown
    by Orville Wright. The first recorded fatality from a birdstrike was in Dec of 1912, when a Wright flyer flown by Cal Rogers.

    Ray
  12. EricGoedkoop

    EricGoedkoop Member

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    I think you nailed it, Gents - looks like everything is going to work out fine. I have a few more nights' work on the nacelle before I can attach the foreward deck, but when I do I'll take some pictures.

    Thanks again!

    Eric
  13. histbuff1190

    histbuff1190 Member

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    the front of the aircraft is metal, with the "windscreen" being made of streched and doped linen. it appears as if the curve were designed in, given the shape of it.
  14. EricGoedkoop

    EricGoedkoop Member

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    Worked out beautifully, guys:

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    I couldn't resist doing the whole front in aluminum, even though the "windbreak" was probably linen. It just looks too cool!

    Again, thanks to all for your assistance. Now it's on to rigging the nacelle, building a fuel tank and engine.

    Then the real fun starts. . . .