[JoeF]

Wing Weight? ... going for low weight
Perhaps the following has not received enough note regarding my personal targets on the Wing5 project.
Wings will come in at some final empty weight. I want that weight to be lower than higher, less than more, lighter than heavier. The wing will be carried on the streets, on the bus, off the bus, moved to the site, carried back from the landing to the the launch points. Every pound that need not be in the wing will save weight challenge in all those movement spaces. The weight for wheeling, toting, moving, placing, replacing, carrying .... is wanted to be lower than most hang glider weights. The "5-ft" polite-bus size is one fence. The other fence is polite weight, pleasant weight, endurance-compatible weight. So, one thinks of exotic materials and compromises in design and flight performance. Weight is part of the formula for pleasant play. 50 lb is better than 60 lb. A 40-lb wing may be much more pleasant for busing and Dockweilering (new gerund) than a 50-lb wing. And a 35-lb wing might satisfy better than a 40-lb wing. And a 30-lb wing might be ever more satisfying.

If a conversion of an Alpha 210(manual) to busable 5-ft polite length and pack without being less weight than a OEM Alpha 210, then I severely question doing such a conversion; keep the stock Alpha 210 for car carry. Conversions could end up heavier or lighter depending material changes. Aluminum to carbon fiber? Etc.
Stainless steel line to Dyneema? OEM weight of Alpha 210 is __51 lb_______. The 5-ft HG Movement has sectors; one sector is "Dockweiler Soft-S Only." Other sectors may have need for safer designs when wing weight may well be higher than needed for wings for the very conservative scene.

Weight of glider with all essential parts and without coverbags and nonessential
parts: 51 lbs

I anticipate building scores of wings meeting the 5-ft deal, but I will be pressing for low weight even with L/D or sink-rate compromises, if needed. Ease of making iterations is interesting. Money is watched, but when a scheme and design seems right, then heavy investment will be accepted to get the empty weight down down down. In very-happy-face wing builds, a stepping to optimize weight would then be initiated.

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Brainstorm reasons to keep stock Alpha 210 unconverted
Available for training
Available for car-topping
Available to sell as is
Available for parallel flying at Dockweiler or other mild training scenes
Available to compare flights with other builds
Conversions won't be same; a new animal will inevitably result.
Available to cover flight needs in case Falcon or Condor 215 become lost, damaged, stolen, ....

[JoeF]

Toward the joining of the batten ribs with mainsail in current Wing5 scheme where ribs will stay in mainsail during pack and tote: -to
The fresh decision to keep ribs installed during pack and tote seems to allow some satisfying opportunities. Recall that set bowstrings with standoffs may be used to give camber for airfoil forming. Various rib materials with various sail materials for the Dockweiler-only-conservative-soft-S-pathing wing for HG will be inviting exploring various rib-to-mainsail join methods. Here is a start of brainstorming toward such joining:
Stapler
Glues
Adhesives
Adhesive tapes
Welding
Intermediate tape that welds rib and mainsail
Interleave slits
Pockets sewn to mainsail. Note: Many other methods will not be of a pocket type.
Sew rib to mainsail by hand or by sewing machine. Many variations stem from this space.
Bond fabric tape to rib; then sew fabric to mainsail.
Say series of holes in rib and mainsail at 3 in separation. Weave line through the holes. This could allow changeout of ribs as wanted to weaker or stronger ribs for experimental changes.
Riveting
Side notches in rib for tying mainsail to rib. Maybe every 3 in along the rib.
Spray adhesive
Contact cement
Heat welding if materials permit
Prepare short sticks of thermoplastic monofilament; melt flange on one end of the small sticks. Make holes in rib and mainsail at specific stations. Poke the small flanged stick through the hole. Press the rib and mainsail at the hole point where the flanged stick is poking through. Then melt a closing flange. This is a kind of riveting. Thermoplastic material. Place as many such rivets as needed. This could be a method in itself. Or this method might be combined with an adhesive method or welding method. Etc.
Hot melt pounded into fabric sail; then after prep, hot melt rib to the treated sail; press until cooled/cured
Sandwich mainsail between two rib parts: rib part above sail and rib part below sail; rivet the sandwich.
?????

[JoeF]

Progress notes for Wing5, first iteration:
1. Will taper spar from root to tip. Will go with about 18 inch for inflated diameter of central station of inflated spar. About 5 in inflated diameter at wing tips.
2. Will have spanwise zipper for spar case.
3. Will keep ribbed mainsail as rectangle, despite spar case taper.
4. Will use spar case as the tote wrapper. Zipper will not get kinked in the wrap.
5. Will go with hook-and-loop for marrying compression elements to the inside of the spar case.
6. Will have lift compression element (CEL) and drag compression element (CED). Aiming for separate tote coiling, but segmented-coupled straights might be.
7. Ribs are to be perma-set to mainsail.
8. Bladder during tote will be separated and protected.
9. CEL and CED will tote separated.
10. There will be variation in rib-support struts.
11. Ribs will use a bow-string and standoff scheme.
12. Note: Inflation adds weight from inserted air. Weight added goes up if psi goes up. It is a little tricky to calculate the weight that will be added to the wing from the inflation fact; the splinted air beam scheme allows using less psi than a scheme without the compression-element structural air-beam splinting. Besides calculating, it will be fun to actually weigh the spar deflated and then weigh the spar inflated to various psi. And then fly with various psi. It will be nice to have a pressure limiter (pressure relief valve) and a pressure gauge. I do not yet know the psi that will give the flights wanted. The tapered spar reduces the volume involved. The mass of air in the inflated splinted spar will be involved in accelerations and decelerations during turns, launching, and landing. Hot days: less air will be needed to get the pressure desired. Cold days: the wing will be heavier for a given pressure desired.
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Image is a sidebar of VJ-23 at Dockweiler

[JoeF]

Bow-string-standoff scheme for cambering? (BSSOS) (one-sided spreader)
Have on batten rib perma-set strings anchored in two separated place along the batten rib. The string may be initially taut or relaxed depending on one's needs. The batten rib material is to resist bending longitudinally. Insert a compression beam "standoff." The standoff might be rough hewn or optimized for compression for a particular use. The standoff will become useless if buckling occurs when serving for safe operations. One may want to know if a particular standoff buckles or slips out of position or disappears from the scene; test such circumstances could be part of the hobby. What if Wing5 is set to glide without any of its standoffs? Or without a particular standoff? Etc. I will want to test many possible eventualities.

Note that a particular batten rib could feature more than one bow-string-standoff arrangement.
Note that a particular batten rib with bow-string-standoff scheme (BSSOS) could feature more than one bow-string. Or more than one standoff in one bow-spring. Variations on the scheme invite exploration.

First iteration of Wing5 will feature batten ribs perma-set into mainsail. The ribs will stay in place while the mainsail-with-ribs is packed accordion-and-roll style to a bundle. The BSSOS strings stay doubly anchored in prescribed batten ribs during pack and tote. If standoff beams are sized so as not to bother the packing and tote, then such standoff beams might be perm-tied to bow strings, unset from batten rib, and thus be available for quick placing to do the standoff for camber tuning. Bow-string anchor points, un-standoffed length, and standoff length will determine effects on camber shape. Fun explorations await the BSSOS involvement!

If a particular standoff for cambering is made in controllable V, then a camber-morphing method might be explored for flight controlling; pull on the center of the V and the camber increases; let off the control line and the V collapses and camber reduces. Fun to explore the Vee-Control method (something I mentioned in DavisOz space many years ago or/and JackSpace, not sure; notes should still be extant).

Bow-string Standoff Scheme

BSSOS001.png (5.53 KiB) Viewed 1371 times

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2VeeStandoffBSSOScamberMorphing.png (4.43 KiB) Viewed 1370 times

Securing standoffs to batten rib and the bow string challenges. Prevent slipping from desired position. Avoid damaging batten rib. Avoid cutting bow-string.

Adventure:
https://www.uksailmakers.com/encycloped ... -your-rig/
https://www.northsails.com/sailing/en/2 ... e-your-rig
https://rigworks.com/standing-rigging-o ... that-stay/
https://en.wikipedia.org/wiki/Standing_rigging
https://goodoldboat.com/spreaders-101/
http://xkqfc.wnwjv.servertrust.com/v/vs ... /j-105.pdf

[JoeF]

BSSOS might be mixed with some rigid non-BSSOS ribs.
Rigid airfoil-shaped ribs bonded to the mainsail in pack will tend to reduce pack efficiency; but maybe the challenge will be solved. Maybe smaller items may fill the cavities efficiently. Central keel rib: rigid. Most outboard ribs: rigid. Mid-wing ribs: BSSOS. TE taut cord may allow such mix to obtain a satisfactory resultant. Net volume is a concern for polite packing besides net weight. Spanwise-string bracing might be used.

RigidRibStringStayed.png (7.4 KiB) Viewed 1359 times

Sail-rib assembly packs by stacking the side faces of the rigid ribs, letting the mailsail gather; such scheme is not as neat as a wholly-BSSOS pack; such matters will be fun spaces for comparing packs and performance.

RigidRibStringStayed3.png (16.79 KiB) Viewed 1358 times

.


Adventure:

[JoeF]

2VribSailGatherPack.png (16.42 KiB) Viewed 1354 times

Recall: The scheme is to have the mainsail approximately rectangle with perma-set ribs and be at pack a separable assembly that can be packed by stack-accordion or coil or combo-stack-coil method. Pack volume is important. Low weight is important. A target is to avoid both rib pockets and separated ribs.

[JoeF]

Flight-load-taking lines that work with the compression element of the inflated spar wrap the spar from spar wing to wing tip; the lines anchor to the tips of the compression elements. At least two lines are used; one starts at wing tip and wraps on the LE of the spar for half the spar and then wraps up in back on the rear of the spar and up to the other wing tip. The second line starts also at a wing tip holding the tip of the compression element, but begins wrapping opposingly from the first line described and ends up at the other wing tip. My Wing5 first iteration will use a flat webbing of DYNEEMA® WEBBING. Width may be just under 0.5 in; but choice might be 1 inch, not yet decided. I am also looking at the following:
Sturges Part No. X-7153 Description: ¾” Dyneema® / Orange Nylon Tubular Webbing
MBS 5,000 lbs. https://www.sturgesmfgco.com/webbing/en ... ng/uhmwpe/ I have no experience with that company, so this is not an endorsement.
Dyneema® is a registered trademark of DSM Protective Materials

See webbing up close ...

[Bob Kuczewski]

Pack volume is important. Low weight is important. A target is to avoid both rib pockets and separated ribs.

I don't remember the make or model of the first hang glider I flew in 1978. It was my instructor's glider, but I do remember that it only had flat batters that were inserted into the trailing edge. These flat battens were only a fraction of the chord length at each spanwise position. They were very light weight, packed flat, and reminded me of paint stirring sticks.

This approach flew well in those days and it allowed aerodynamic forces to fill the curved leading edge portion of the airfoil. Of course it was a single surface glider with a conventional frame. Your airbeam may create complications to this simple approach.

[Bob Kuczewski]

Via text messaging to Joe on June 27th, 2021:

Let's convert the Alpha to a 5' busable glider.

We can start by disassembling it and figuring out what tubes to cut.

As an alternative to cutting the existing tubing, maybe we could construct a new busable frame for the existing sail. It could be of simplified construction like the older gliders. Would you like to give that a try?

[Frank Colver]

My WW SST had flat battens that were shorter than the chord. It flew very well for its day but I greatly appreciate the cambered full battens of today's flex wing gliders, because the sails don't collapse or go negative in turbulence anymore.

Frank