That is the reason I don't want to mess with the air foil -- I know there is more than one air-foil (though I believe the inboard air-foil is the same, so making that part constant shouldn't be a problem) and I personally don't have the expertise to make anything better. I'm not sure if we have any aero guys watching, or any that would want to re-look at that, but AFAIK, the current air-foil isn't 'bad' enough to redo, or am I missing something?


Manufacturability is important, but there is no way that I know of to make this so easy, or so cheap and still meet the other design goal of 155 Lb Chopping off a couple of 2X4s and banging them together with nails sounds sweet, but it ain't going to happen like that. There will need to be some carbon, and that's not cheap (damn Boeing and Airbus for sucking up all the worlds inventory of carbon!... nearly).


The D-skin would have to run through IMO -- the Arc does the same thing, but does use Mylar in the skins to see through. I"m not sure what they are using on the rest of the wing...


Why would you want to eliminate the flaps? weight saving?







sounds cool guys...the dragon has moor than one foil type in the wing.
why not leave the flaps off? good idea with the one pice flap and lifted boom and controll point on the trailing edge(watch waighting the back of the flap with controll rods/hardware)
will the centre section of the 3 part wing be open?or will the d scin run right through?
right through is good and strong but vision again..our head is back under the wing again.

no mony coming kenny:( shame i worked out the mixer/controlls this morning...also landing gear position....but i did see some problems in vision again.

i like the idea that a shorter span plank can stay in one pice..removable fin...one man set up...lives in its trailer...easy to build.

a design competition..yer..thats what we need......the pw 5 came about from a design competition..i seen in an old magazeen a table full of models from this competition ..all types of configurations.

some one on here said the average age of a glider pilot was 53?
i think at this weight/class we will be looking at a younger pilot...befor kids not after..the hang ,para pilot..if aceopterex was $5000 we would all have one.
this market needs to be able to build in 3 months/over winter(other wise projects stall)...better glide,sink rate than there hang glider..costs under $2000 to build...easy to get materials...super safe...one man set up....the problem is no one wants to build or fix things any moor....they want to buy it ready to go.

hope this helps when you are thinking about your designs...simple safe cheep compact is moor important than performance.
russ.



On Fri, Mar 23, 2012 at 10:13 AM, Kenny Andersen <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:


the thickness adds strength, and without knowing the air-foil at every BL there is no way to know what they are designing into the Arc wing and therefore impossible to copy (IMO)


Is the CD wing need changing for some reason other than thickness? I thought that the thicker wings were stronger, and a low speed (where the CD flies) the drag wasn't so bad (and maybe more drag at a higher speed not a terribly bad thing either in this case).

--- On Thu, 3/22/12, KarlS <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:


From: KarlS <This email address is being protected from spambots. You need JavaScript enabled to view it.>
Subject: [Carbondragonbuildersandpilots] Re: CDII -fuselage
To: This email address is being protected from spambots. You need JavaScript enabled to view it.
Date: Thursday, March 22, 2012, 1:52 PM




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:
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> 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.
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> My thinking right now is:
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> 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.
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> Boom: 3-4 inch boom that inserts through a rear spar which is local to the 'cockpit' area, then pins into the main spar
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> 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.
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> 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
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> 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.
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> 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.
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> 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.
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> --- On Wed, 3/21/12, russell wilson <ruzty27@...> wrote:
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> 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
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> 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.
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> On Thu, Mar 22, 2012 at 1:48 PM, Kenny Andersen <kennyrayandersen@...> wrote:
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> 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.
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> --- On Wed, 3/21/12, russell wilson <ruzty27@...> wrote:
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> Subject: Re: [Carbondragonbuildersandpilots] Re: CDII -fuselage
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> 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
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>  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.
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> 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.
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>  the tempest is a 70 kg glider...a pilot lenthened the alerons to improve roll controll..it fluttered and killed him. russ.