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  1. ULF

    CriCri Composite

    Yes, pultruided Yes, industrial pultruded rods are a must for spar caps. https://shop1.r-g.de/en/art/710101RPSALE50 I thinkI´ll buy 4 of those, they are long enough, and have plenty of meat to sand of. John.
  2. ULF

    CriCri Composite

    Hi Billski, Bob mentioned you are an engineer, and I wanted to ask for your opinion. On aircraft, it is not uncommon, to oversize parts sometimes, for practical use, groundhandling and so on. I did some preliminary calculation about the size of the upper carbon spar capstripe, for 9g. The...
  3. ULF

    CriCri Composite

    haha, well once every 5 years, on a windy day, I`ll probably survive without prtmanent damage! I always wondered what that smell is. Many thanks to the master!
  4. ULF

    CriCri Composite

    Hi there, Short pieces of 2ft, or under give excellent results hotwired. Very accurate cuts. John
  5. ULF

    CriCri Composite

    Hi Bob, Searching for carbon fibers I came across bidirectional non- crimp fabric https://shop1.r-g.de/en/art/192150127-EBA, with unidirectional layers +45°/-45, there I saw, some +45°/-45°, and others -45°/+45°. I`have never used such bidirectional stuff, I used plain weave, cut 45°. Do you...
  6. ULF

    CriCri Composite

    Well, honeycomb building tehcnique is far beyond my abilities .
  7. ULF

    CriCri Composite

    As model plane builder, they use one ort to layers of cellulose filler and sand the balsa, to prevet it to get soaked with the heavier resin. i don`t know if that is acceptable or real airplanes. I guess I`ll stay with PVC.
  8. ULF

    CriCri Composite

    Well the size, 2,2m, where do those numbers come from? And then I ask myself wher does the 80kg emty weight come from? Do the engines weight so much moore than mine? (both may be 13kg).
  9. ULF

    CriCri Composite

    No question, it is absolutely optimized, aerodynamically! But +8, -6g? Besides I doub`t that one would be able to pull that kind of lift off a 3m2 ( 33sq.ft) large wing, with an airspeed of 150mph. I mean it`s designed to beat a fighter jet. That makes 80Kg.
  10. ULF

    CriCri Composite

    You are right, I`m not aiming to save a few pounds, I`m trying to not produce weak spots, and not to waist weight. I`m asking here and there, and try to estimate strenght, before I start to laminate. Sofar I have a pretty clear picture of how to make the wing: As mould I`ll use wire cut pu...
  11. ULF

    CriCri Composite

  12. ULF

    CriCri Composite

    On the original cricri the Fuel is in the pilots crotch, between his knees. To the solid core methode: The Cricri wing has 22% thickness. And I`m planning on building a sprar for the entire bending moments for ~ +8 -6g. The skin needs only be tough on the D-cell. The rest could litterally be...
  13. ULF

    CriCri Composite

    The total chord of the wing is 2ft, (24") , that is pretty much on the limit. For a RC model I could change aerodynamics, but not on a cricri that i would plan to fly in with. I don`t dare. You seem to be experienced in that composite technique, may I ask what you do? My thought is. Build a...
  14. ULF

    CriCri Composite

    Hi Bob, the HTML is not my thing. Thanks for sharing your experience with me! You know, I`m a epoxy- model plane builder, lately I finished a ULF-1 glider, and the dimensions of the cricri are so tempting to me. I´d like to fly in it. Each wing is only 2m ( 80in)span, with the spar sitcking...
  15. ULF

    CriCri Composite

    Thanks, greate info! John
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