Great quotes Kenny.

One thing that is obvious to me it the thickness of the CD wing.

I am not complaining but simply seeing an opportunity.

If we go with the square/rectangular center section I think you could build a box beam with graphlite rod using the front spar and the rear spar as the front and back of the box beam.

Square all the rods and run diagonals for torsion resistance. Super light and your are not going to bend/break/twist it very easily.

You could use the angle metal to make your forms for the box beam as I describe a few posts back.

The ribs could be bent over or slid over the structure.

The D tube could then be significantly lightened as not to carry loads but just shape the airfoil. Vne air pressure would determine the strength for the leading edges. Perhaps foam leading edge ribs spaced as needed.

Mark Calders walk step on his wing type deal using composite sandwich light weight layups.

I'm seeing hyper light.

Kenny are you thinking the same cord and shape as the Arc wing? My vote it on that.

One more thing about the center section. Because the CD wing is so thick you could bring the boom in on the top side of the wing and blend it into the airfoil.

Reason being you could run an un split flap the whole length of the center section. When retracted it would be up against the boom.
This reduces hardware/linkages and weight. Actually you could use the trailing edge of the flap as the attach point for the flap control rod.

Just thinking out loud here guys. I see this plane as very easy to build.

And Kenny I was taught measure with a micrometer, mark with chalk, and cut with the ax.

Karl

--- In This email address is being protected from spambots. You need JavaScript enabled to view it., Kenny Andersen wrote:
>
> Edison said invention is 1% inspiration and 99% perspiration. Tesla, who was smarter than Edison by a fair piece, said of Edison that if he would spend 10% of his time thinking he could avoid 90% of his work. There is no chance I will send you any money, but I will start modeling the wing, and ribs shortly -- still working on getting the software -- it shouldn't be long now.
>
> My thinking right now is:
>
> Wing: a three-piece wing -- flat center section, slight dihedral at the joints and the same airfoil as the current CD wing. It seems well behaved and I can't see any compelling reason to go with a different airfoil, so basically it's the CD wing with a slight tweak.
>
> Boom: 3-4 inch boom that inserts through a rear spar which is local to the 'cockpit' area, then pins into the main spar
>
> Pod: a carbon-tube truss with a sling to start -- that may be what is required to keep it to 70 Kg, we'll see. The fairing for the pod would come later, after everything is ironed out. At 25-40 mph I think you could get by without a fairing for a while, and that will give you an opportunity to get the balance right.
>
> The Arc uses a flap over the center section and ailerons outboard -- that actually seems pretty clever as everything that does a certain job is packaged together
>
> I'm thinking there could be a diagonal truss (like the current CD) that goes from the short aft spar to the front spar which would make a member capable of reacting the wing fore/aft loads and also the wing torsion loads. THe one nice thing about not having a joint at the maximum wing bending is that you enf up with some pretty light carry-through structure. Some of that weight will return at the outboard wing joints, but it shouldn't be anything unmanageable.
>
> First I'm going to do some weight trade studies with some unconventional lay-up concepts that I have that might result in some weight-savings. I'd rather spend some time doing the trade studies and analysis, rather than just swinging an ax at the problem.
>
> Fins, Rudder:
> I don't really see a compelling reason to change the size or profile -- obviously the internals should be looked at, if for no other reason than fun.
>
>
>
> --- On Wed, 3/21/12, russell wilson <ruzty27@...> wrote:
>
> From: russell wilson <ruzty27@...>
> Subject: Re: [Carbondragonbuildersandpilots] Re: CDII -fuselage
> To: This email address is being protected from spambots. You need JavaScript enabled to view it.
> Date: Wednesday, March 21, 2012, 10:28 PM
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Â
>
>
>
>
>
>
>
>
>
> hi kennyconstant cord wing.or dragons wing. reflex airfoil. very short boom. dragons fin/rudder. fuselage/pod ...3'' diameter carbon tube that scribes a line round the pilot when he is viewed from the side.open or a polly bubble on each side.or a structual pod shell.
>  controls ..mixed flaperons with push pull cables like jetski steering. send me $1500 and ill build one in 8 weeks using my carbon dragon wings and fin/rudder..as a proofe of consept...ill weigh it and fly it...then you come here and fly it and see what you think.
> Â russ.
>
> On Thu, Mar 22, 2012 at 1:48 PM, Kenny Andersen <kennyrayandersen@...> wrote:
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Â
>
>
>
>
>
>
>
>
>
> Russ, how many time are you going to repeat yourself?  WE get it, if you don't want to get involved, don't.  If the Arc can hit sub 70KG weight, we can too, something may have to give, or we might have to get a little cleaver.  If you have an idea other than plywood, I'd be happy to hear it.
>
>
> --- On Wed, 3/21/12, russell wilson <ruzty27@...> wrote:
>
>
> From: russell wilson <ruzty27@...>
>
> Subject: Re: [Carbondragonbuildersandpilots] Re: CDII -fuselage
> To:
> This email address is being protected from spambots. You need JavaScript enabled to view it.
> Date: Wednesday, March 21, 2012, 8:37 PM
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Â
>
>
>
>
>
>
> yer?..were talking about a 70 kg carbon dragon not an 80 kg ish magic dragon .....we are talking about replacing the wood d tube with carbon and trying to keep it the same weight....talk to steve again and ask him how thick his scin is and then calculate the weight diferance..wood to carbon will be...and ask him how heavy his magic dragon is.the filler and paint alone he has on his ship will tip the scales over 70 kg on a standar dragon most finished standard dragons are over 70 kg.... then add carbon with a density of 1.8 and he also has glass in his d skin dosent he?..density 2.6..resin 1 to 1.3
>
>  i think i have the following right....if you doble the thickness of a beam ..it is 8 times stronger and 36 times stiffer....i cant remember if the numbers are right. if your goal is to have a dragon that weighs 70 kg or under and you are going to use carbon for a d scin then some thing has to give...what will it be?will you cut some thing off the aircraft? the wing tips?will you change the design?geodetic d scins?will you thin the d scin?will you go over 70 kg.or will you come back to wood.
>
> Â my advice is to use what the plans call for..if you feel carbon is for you then make a carbon d scin that is the same thickness as the wood..ie a heavy d scin.....do not make the ribs hevier..do not weight the back of the wing.
>
>  the tempest is a 70 kg glider...a pilot lenthened the alerons to improve roll controll..it fluttered and killed him. russ.