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TOPIC:
Re: CDII 3-part wing 07 Dec 2013 17:40 #311
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Does anybody else see a center section of the wing? This is more or less the concept to build the wing on I was thinking. Simple it is?
Thoughts? groups.yahoo.com/group/Carbondragonbuild...inal&start=1&dir=asc --- In This email address is being protected from spambots. You need JavaScript enabled to view it., "KarlS" > > I suppose it would require some rigging but it would depend on how far you took it apart. The young lady and gent did it on a slope. > > Pip pins and fork connectors wouldn't take that long. The tail boom could be pip pinned on as well if it was in a fork configuration and slid up onto the wing center section. > > You could do partial tear downs like the photo of the Mitchell A10 on the trailer I posted. > > Design folding wings and you're talking even faster. > > Here's a couple good shots of the dihedral and possibly some washout. > > groups.yahoo.com/group/Carbondragonbuild...inal&start=1&dir=asc > > and > > groups.yahoo.com/group/Carbondragonbuild...inal&start=1&dir=asc > > Karl > > --- In This email address is being protected from spambots. You need JavaScript enabled to view it., Kenny Andersen > > > > Right, so if you wanted to put a little dihedral you could do it at the joints outboard joints rather than at the center. In the end, I think the 3-piece wing would likely be a bit lighter, but then wouldn't you want the boom to disassemble? THat makes storing the wing a little more diffidult if you don't. I know the Arc separates the boom form the center section, which means you have to rig the controls every time you hook it up, no? > > > > --- On Tue, 3/20/12, KarlS <kschneider@> wrote: > > > > From: KarlS <kschneider@> > > Subject: [Carbondragonbuildersandpilots] CDII 3-part wing > > To: This email address is being protected from spambots. You need JavaScript enabled to view it. > > Date: Tuesday, March 20, 2012, 9:59 AM > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >  > > > > > > > > > > > > > > > > > > > > Phil, > > > > My apologies but my proposal was for the new CDII ship and not to redesign the current CD wing. > > > > > > > > Basically it would be scrapping the current CD wing. > > > > > > > > I changed the subject line. > > > > > > > > Here's a top view of the Arc. (by the way your spelling was right  )> > > > > > > > groups.yahoo.com/group/Carbondragonbuild...inal&start=1&dir=asc > > > > > > > > In the new wing the center of the wing is a Hershey bar shaped from the end of the flaps corner to corner. Constant chord, constant airfoil thickness, linear as it gets. > > > > > > > > This yields easier to build. There would be no deflection in the rods. They would bend by the way if needed. I have 100 ft of them in the basement in a 3.5 foot diameter roll. > > > > > > > > Phil sorry for throwing in the wrench. > > > > > > > > By the way.. any idea of the airfoil on the Arc? Looks like the top of the fx63-137 but flat bottomed. Or something similar to what they did on the Axel. Its definitely flat bottomed from about 25% back. > > > > > > > > Karl > > > > > > > > --- In This email address is being protected from spambots. You need JavaScript enabled to view it., "Philip Lardner" > > > > > > > > > > Starting a new thread... > > > > > > > > > > Hmm... I hadn't really considered a 3-part wing until just now! I remember > > > > > seeing that video of the prototype Arc a long time ago but I never > > > > > considered the benefits or build implications - thanks for prodding us in > > > > > this direction Karl! > > > > > > > > > > Benefits (as I see them): > > > > > > > > > > * > > > > > > > > > > Shorter wing components = easier to transport / store / handle / > > > > > assemble. > > > > > * > > > > > > > > > > It also removes a potential weak spot that is the aluminium > > > > > root-join fittings and moves them outboard where the loads are much less, > > > > > and maintains an unbroken carbon rod spar at the highest load area across > > > > > the root. I like that a lot! > > > > > > > > > > Problems & build implications (as I see them): > > > > > > > > > > * > > > > > > > > > > Trickier main spar central section to fabricate - remember, it's > > > > > bent in the middle! Will the carbon rods bend enough? > > > > > * > > > > > > > > > > Two sets of (lower load) wing connectors, not easily accessed > > > > > without breaking the skin covering with some sort of access panel = > > > > > disrupted airflow (maybe.) > > > > > * > > > > > > > > > > Two join lines that need to be perfectly aligned/faired to maintain > > > > > smooth air flow (on the flaperons also.) > > > > > * > > > > > > > > > > Two extra ribs - fore and aft of the main spar and flaperon (extra > > > > > weight, but no big deal.) > > > > > * > > > > > > > > > > Extra hardware required to connect the three wing parts and two > > > > > parts of each flaperon. > > > > > * > > > > > > > > > > Spoiler and deployment arm will need to be redesigned (could this be > > > > > completely replaced by a controllable drogue?? > > > > > * > > > > > > > > > > Pilot would definitely need to be under the wing, which would > > > > > definitely mean a new pilot pod and control rod design! > > > > > * > > > > > > > > > > Not sure my workshop will be long enough to accommodate > > > > > building/aligning both the centre section and one wing tip section bolted > > > > > together - it's barely 25 feet long! > > > > > > > > > > Hmm... drat, now I'm going to have to think again!! > > > > > > > > > > I do like the idea of shorter wings when disassembled though - much easier > > > > > one-man handling. > > > > > > > > > > The big issue to overcome with a 3-part wing is how best to join them and > > > > > the flaperon halves, and what to do at the flaperon root. I suppose we could > > > > > use a variation on the original root connection fitting, with the metal > > > > > fittings slotting into cut-outs in the root of the wing end rib... if you > > > > > get me! You would also need a very solid method of preventing the ends/edges > > > > > of the ribs at the joins from moving or flexing, which might cause the > > > > > flaperon parts to bind - and similarly on the trailing edge of the flaperon > > > > > at the joins. > > > > > > > > > > So, where do we split the wing parts? Thinking about handling and trailer > > > > > storage, let's pick some arbitrary positions... if we split the wing into 1 > > > > > x 22 foot long centre section and 2 x 11 foot wing ends, the centre 22 foot > > > > > section will be a handfull to manage on your own but can be packed up in the > > > > > trailer relatively easily (just two wing thicknesses.) > > > > > > > > > > If we go for easier one-man handling, we could split the wing into roughly > > > > > equal thirds = 14.6 feet per section = much more manageable, but trickier > > > > > trailer packing Let's ignore the trailer problem for now! > > > > > > > > > > In my design (run your own figures through my spreadsheet) the 1g load on > > > > > the spar cap at rib #5 is 606.19lbs, down from 1265.92lbs at the wing root! > > > > > At 8g those loads increase to 4849.56lbs, down from 10127.33lbs at the wing > > > > > root. So, the loads are roughly half those experienced at the original root > > > > > fittings, and the new fittings can be made smaller and lighter. However, > > > > > even reducing the strength and weight of the carbon load transfer bars and > > > > > metal fittings appropriately we will almost certainly be adding a little > > > > > extra weight. I'll work out theexact wing connection fitting design later, > > > > > but it would be neat if we could use strong pip pins rather than AN bolts to > > > > > do the job (I'm not holding my breath on that!) > > > > > > > > > > Rib #5 is 85.5+8.25 inches = 93.75" = 7.8 feet out from the wing root, so > > > > > the centre section of the wing would end up at 15.625 feet long and the > > > > > outer wings would each be 14.19 feet long. > > > > > > > > > > Arguments and ideas please! > > > > > > > > > > Phil. > > > > > > > > > > _____ > > > > > > > > > > From: This email address is being protected from spambots. You need JavaScript enabled to view it. > > > > > [This email address is being protected from spambots. You need JavaScript enabled to view it.] On Behalf Of KarlS > > > > > Sent: 20 March 2012 09:21 > > > > > To: This email address is being protected from spambots. You need JavaScript enabled to view it. > > > > > Subject: [Carbondragonbuildersandpilots] Re: CDII -fuselage > > > > > > > > > > > > > > > > > > > > > > > > > I know you gentlemen are thinking of the 2 part wing with a center box but I > > > > > would once again like to mention a 3 part perhaps folding wing. > > > > > > > > > > Once again a 3 part wing eliminates the heavy most likely to fail highest > > > > > stress part of the airframe as per Dieter Reich. I bet Ruppert wishes they > > > > > stayed with the 3 part wing like their prototype. > > > > > > > > > > Here's a photo for thought. > > > > > > > > > > groups.yahoo.com/group/Carbondragonbuild...ots/photos/album/212 > > > > > 271473/pic/495742754/view?picmode=large > > > > > <groups.yahoo.com/group/Carbondragonbuild...lots/photos/album/21 > > > > > 2271473/pic/495742754/view?picmode=large&mode=tn&order=ordinal&start=1&dir=a > > > > > sc> &mode=tn&order=ordinal&start=1&dir=asc > > > > > > > > > > Here's the spin characterists for the Arc and also the highest stress area > > > > > failing. > > > > > > > > > > > > > > > > > > > > Now that we are in the early stages of design concept I am putting the 3 > > > > > piece wing up again for discussion. > > > > > > > > > > Rupperts original 3 piece wing. > > > > > > > > > > vimeo.com/29536897 > > > > > > > > > > Regards, > > > > > > > > > > Karl |
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