Is there a cheapest/lightest/simplest wing structure other than aluminium tube and fabric?

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jedi

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???? Translations??
TANSTAAFL
Referring to the title of the thread "Other than Aluminum tube and Fabric" consider other ways to use the Aluminum tube and fabric. The Quicksilver "ladder" and the Rogollo "A frame" are two successful methods. The Wheeler/Skycraft Scout of post # 3 and the Tensegrity wing with cap-strips space frame of post #143 are other examples that can be built upon. IMHO the Tensegrity concept has a future but needs to have additional innovative development.
 

oriol

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I think the prospective AG hybrid concept of airship/wing is too draggy to be an efficient hanglider and lacks sufficient volume to be a useful airship. That being said, it is still an interesting idea!

I agree in the inmense appeal of the Quicksilver as a simple solution. However a modern a pendular aircraft wing is even better in terms of fodability and performances.

An inflatable space station might be dangerous in case of a debris hitting it?

Cheers,

Oriol
 

cluttonfred

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TAANSTAAFL "There ain't no such thing as a free lunch." American bars used to offer "FREE LUNCH" to get people to come in and buy drinks (which means they just charged more for the drinks). By extension, anything that sounds free usually isn't. Expression goes back to at least the 1930s and is probably older than that and was made popular by science fiction writer Robert Heinlein in his novel The Moon is a Harsh Mistress (1966). See TANSTAAFL by Robert Heinlein from The Moon is a Harsh Mistress
 

Riggerrob

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... An inflatable space station might be dangerous in case of a debris hitting it?

Cheers,

Oriol
A friend (parachute rigger) worked as a technician on Bigelow Aerospace's inflatable module that was added to the International Space Station. They used multiple-layer walls made of puncture resistant fabric to limit the damage done by small bits of space trash. Large bits of space trash will puncture any metal space craft.

On the subject of inflatable kayaks, there have been at least 5 generations.

The first generation of foldable kayaks (Klepper, Folbot, et.) were built the same way as the original Eskimo (Inuit in Canada) with sticks covered in fabric. Clever joints allowed the user to quickly assemble the wooden frame and stretch the fabric around the outside. I used to have a Folboat and spent many leisurely hours using it to explore local rivers and lakes.

Later versions of Folboat added inflatable tubes along the sides to tighten the hull and provide some emergency floatation.

The third generation only used inflatable tubes (ala. inflatable emergency life raft). These were great for white-water rafting, but lacked the long-sleek hulls needed for speed and efficiency on long trips.

The fourth generation (Advanced Elements) has inflatable tubes enclosed in a second layer of heavy-duty fabric. It also has aluminum stiffeners in the bow and stern to increase the finesse ratio (length to width). It works well, but is overly complex and slow to dry.

The latest generation uses through-stitched side walls and bottom. This is similar to the Air-Mat that Goodyear used to build their Inflate-O-Planes circa 1960. These have far fewer parts because they do not need an extra, outer layer of fabric for streamlining. They can be built as perfectly flat sheets or gently curved sheets (similar to plywood). The 2 layers of fabric are held at a constant distance by thousands of through-stitches. Try to picture rib stitching on a fabric-covered biplane. Outer layers carry most of the tensile and twisting loads, while through-stitches hold them in precise alignment and compressed air (5 psi above atmosphere) carries all the compressive loads ... sort of a tensegrity structure with compressed air replacing all the little sticks. These inflated boats stay rigid as long as internal pressure exceeds external pressure. These double-layer sheets are similar to the through-stitching currently fashionable on inflatable stand-up paddle-boards.
Current through-stitch sewing machines can only make constant-thickness sheets, but I predict that the next few years will see more sophisticated machines that will be able to sew contoured hulls of varying thickness. I anticipate that sophisticated through-stitch machines will soon allow square parachute (and para-glider) factories to eliminate all the finicky ribs currently sewn into their inflatable wings.
 
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Victor Bravo

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Actually, now that I think of it, the simplest and cheapest (and maybe equally light) aluminum tube wing is going to be the Graham Lee/Baslee style using riveted bent tubes as ribs. A strut braced wing will be lower parts count than a wire braced wing, but the wire may cost significantly less than the strut tubes and hardware... one of our genius caliber engineers here can quantify that easier than me.

The reason this (fixed tube-rib) is a bit less complex overall than the Quicksilver style wing is that it does not require removable rib "battens" and their attachment parts, and the covering is greatly simplified because you don't have miles of seams for the batten pockets. That sewing takes time and a commercial sewing machine, and the majority of Quicksilver owners have to repeatedly "buy new sails" at a fairly painful wallet wallop.
 

cluttonfred

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That’s interesting, henryk…D-cell leading edge spar, rigid ribs, cable trailing edge?

VB, I agree to a point, but on the ribs there is more than one way to skin a cat. Bent tubes, stamped sheet metal, aluminum angles and widgets, plywood or or built up sticks or foam epoxied in place, plywood and aluminum angle brackets, or various hybrid designs can all work and be a simple and cheap. Even welded steel tube works great for tails though it’s prohibitive for wings in terms of weight. It just depends what material you can get, what tools you have, and what you like to work with.
 

J.L. Frusha

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Honestly, I think the composite construction of the Chotia Woodhopper/Gypsy wing is about as simple and light as it gets. Rework the spars for more strength, use carbon fiber tubes like the Gossamer Albatross' fiberglass tube structure, but filled with expanding foam to further reinforce it and eliminate the cable supports?

The spars would be a PITA to make, but still doable at home-built scale.
 

AeroER

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"D" -CF tube (possibility)=

-this mode, +resin infusion.

result=
The video reminded me of the trapezoidal cross section cruise missile fuselages my sister was winding in 1983. She worked as a M&P engineer at the time, trying many different ideas for producing the fuselage as low cost and quickly as possible. I don't believe anyone had built fiber placement machines at that time, but we had those operating by 1990. Later she was working on wound turbine engine cases.
 
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Bill-Higdon

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The video reminded me of the trapezoidal cross section cruise missile fuselages my sister was winding in 1983. She worked as a M&P engineer at the time, trying many different ideas for producing the fuselage as low cost and quickly as possible. I don't believe anyone had built fiber placement machines at that time, but we had those operating by 1990. Later she was working on wound turbine engine cases.
Back in the70's they had multi axis CNC fiber winders, took a Large PDP-11 to run them
 

Aesquire

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Rework the spars for more strength, use carbon fiber tubes like the Gossamer Albatross' fiberglass tube structure, but filled with expanding foam to further reinforce it and eliminate the cable supports?
The Albatross used aluminum tubing, wrapped with carbon fiber, then dissolved away with pool chemicals. Expanding foam in the tube would just add mass. The Enemy. The cable supports were the basis for the light weight minimum structure, essentially a bowsprit hang glider structure scaled up.

But you could, bond 2 stacked tubes as a main spar for strut or cantilever wings. The Airdrome Baslee wings are often built that way, except aluminum & rivets. ( instead of composites & glue ) BUT It's heavier than a well designed D tube structure. Baslee uses that technique to take advantage of readily available tubing, and the same rivet & gusset system is used throughout. Fast, cheap and easy.

Sandlin's first efforts were improved Quicksilver hang gliders with "doped" fabric and better airfoil than the single layer sewn originals.

Just because I prefer bolted construction doesn't mean the rivet & gusset system is bad, it's not, it's just the first system I learned from building hang gliders from plans, and it offered a very fast way to do experimental shapes by changing parts in the field with no or few tools.

Also I took inspiration from testing done at the Original American Aviation Think Tank/Skunk Works, McCook Field.

One technique was to build the horizontal stabilizer and elevator oversize, then on subsequent flights, cut fabric away to find the smallest area needed for stability and control. I "improved" on the turn around time by using duct tape & plastic instead of doped fabric. Fly, trim , fly, at the local training hill made multiple iterations in one day possible.
 

J.L. Frusha

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The Albatross used aluminum tubing, wrapped with carbon fiber, then dissolved away with pool chemicals. Expanding foam in the tube would just add mass. The Enemy. The cable supports were the basis for the light weight minimum structure, essentially a bowsprit hang glider structure scaled up.

But you could, bond 2 stacked tubes as a main spar for strut or cantilever wings. The Airdrome Baslee wings are often built that way, except aluminum & rivets. ( instead of composites & glue ) BUT It's heavier than a well designed D tube structure. Baslee uses that technique to take advantage of readily available tubing, and the same rivet & gusset system is used throughout. Fast, cheap and easy.

Sandlin's first efforts were improved Quicksilver hang gliders with "doped" fabric and better airfoil than the single layer sewn originals.

Just because I prefer bolted construction doesn't mean the rivet & gusset system is bad, it's not, it's just the first system I learned from building hang gliders from plans, and it offered a very fast way to do experimental shapes by changing parts in the field with no or few tools.

Also I took inspiration from testing done at the Original American Aviation Think Tank/Skunk Works, McCook Field.

One technique was to build the horizontal stabilizer and elevator oversize, then on subsequent flights, cut fabric away to find the smallest area needed for stability and control. I "improved" on the turn around time by using duct tape & plastic instead of doped fabric. Fly, trim , fly, at the local training hill made multiple iterations in one day possible.
Matter of balancing your trade-offs and reasoning. Carbon fiber tubing doesn't resist impacts well. Filling with foam to reinforce the tubing, reduces that, increases overall strength as well, allowing for fewer, or possibly no cabling, while reducing drag due to cabling. Foam is generally lighter than aluminum and steel.
 

raytol

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I like using the small rectangular pultruded carbonfiber rods supplied by Jim Marske and now Aircraft Spruce. There is plenty of carbonfiber plate and small ( round and square) tubes around which can be used for gussets and hard points. The wing spar webs can be built in trusses with the caps attached by gussets. A "D" box can be laid up in a simple mold. The fuselage can be built the same way. It is a bit more toxic than working with wood but so much stiffer! I saw a primary glider in Germany built by Ursula Hanle (Glassflugel) that had aluminum tubes tied together with wet out fiberglass rovings. It worked.
 

addicted2climbing

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Even worse... They didn't use locking nuts, or pre-stretched leader, so they played Hell keeping tight. They thought they had "turnbuckle creep" but testing the turnbuckles didn't show that. smdh

Some people don't have the sense to come in out of the rain, or ask for help. I could've told them what their problem was. That's why I'll go with the lighter UHMWPE rope.

Oh, btw, that's the misleading pic. Here's the web as drawn for actual construction...

View attachment 120726
If someone were to show up for an annual from an IA with a wing built like this, I bet you'd be asked to go elsewhere....
 
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