Re: Quickie Q1 Canard and wing foam cut


Robert Cringely
 

No thanks. This is not at all a critical design. Since it is a wet wing I have had to add an extra ply that is completely redundant and WAY overbuilds the structure. Also the LS-1 wing is a little shorter, reducing landing loads somewhat. I had my buddy who is a design engineer at SCALED Composites run the ply schedule through his computer and he also said it's overbuilt, though the actual structure will likely be lighter because it is pre-preg with much tighter resin control. Yes, we've built and tested coupons.


On Thu, Sep 16, 2021 at 12:44 PM Rob de Bie <robdebie@...> wrote:
Nice site, decent data. But most applications look mostly cosmetic and/or low loaded. I think you
are pioneering with the material, make really sure that you are safe! Like with those hot/wet
specimens to check long-term resin adhesion. Should I look up that article to give you some guidance?

Rob


On 16 Sep 2021 20:27, Robert Cringely wrote:
> It seems to be working fine for me: https://lingrove.com/ekoa-prepregs
> <https://lingrove.com/ekoa-prepregs>
>
> On Thu, Sep 16, 2021 at 11:04 AM Rob de Bie <robdebie@... <mailto:robdebie@...>> wrote:
>
>     Bob, when you mentioned flax fibers I peaked my ears! I've worked a bit with flax composites
>     some 15
>     years ago. Is the material mature enough to use in an aircraft? I remember problems like no
>     suitable
>     sizings being available to optimize fiber-resin adhesion, moisture content during curing leading to
>     degraded resin adhesion & quality, and moisture absorption during use leading to lower properties.
>     Sounded to me like it would a lot more development before it would be safe to fly. But it was 15
>     years ago.
>
>     I also remember reading in an eighties issue of 'Homebuilt aircraft' magazine that hot-wet test
>     specimens could be good indicator of the longer-term quality of the fiber-resin adhesion. Sounded
>     reasonable to me.
>
>     Rob
>
>     On 16 Sep 2021 17:39, Robert Cringely wrote:
>      > Thanks! I’m using a no-name 680cc aluminum air-cooled V2 diesel to which I am adding a tiny
>      > turbocharger and intercooler. What’s changed since you looked is probably direct injection.
>     Engine
>      > weight is around 50kg. I’m adding a belt drive from Ace Redrives in India. It’s 1:1 because I
>     don’t
>      > need a slower prop but I do need to raise the thrust line and to isolate the prop loads from the
>      > mystery metal Chinese crankshaft. I’m probably a year from flying, by which time I will have
>      > replaced most of the airframe with vacuum-bagged pre-preg. It’s not carbon or glass — it’s flax
>      > fiber, which fits right between e-glass and s-glass in performance, with a little Coremat
>     added for
>      > stiffness.
>      >
>      > Bob
>      >
>      > On Thu, Sep 16, 2021 at 8:16 AM Hot Wings via groups.io <http://groups.io> <http://groups.io
>     <http://groups.io>> <bd5er=aol.com@groups.io <mailto:aol.com@groups.io>
>      > <mailto:aol.com@groups.io <mailto:aol.com@groups.io>>> wrote:
>      >
>      >     What diesel engine are you considering?  I looked at the V-twin Chinese diesels more than a
>      >     decade ago and discarded the idea as not practical.
>      >     There are some interesting marine 2 stroke diesel development projects nearing market
>      >     introduction that may provide some of us with a 100LL option.
>      >
>      >     Look up Alan Thayer (sp) in the archives.  He had an LS-1 canard designed using Graphlite
>      >     rods.Attached is a *.ZIP file of some of his work.  Graphlite is no longer a practical
>     source of
>      >     carbon rods for us as they are quite unwilling to sell rolled lengths of material.  The
>     Chinese
>      >     suppliers are willing and at a considerable savings in cost.  Preliminary tests have
>     indicated
>      >     the quality/strength is as good as the US sourced material.
>      >
>      >
>
>
>
>
>
>





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