[JoeF]

Wing5July5of2021notes.png (13.23 KiB) Viewed 1265 times

[JoeF]

Air pressure in the Wing5 spar
Current estimate: under 5 psi, probably 3 psi or even less. Flights will be explored for 1 psi, 2 psi, 3 psi, 4 psi, 5 psi. Inflation to burst failure will be done before a spar is made for flight testing. Such is less than kiteboarders' LEI pressure because of the air-beam splinting scheme.

Air pressure will be checked just before each flight.
Inflation will be by manual pumping.

Adventure:

At 10 psi, he showed buckling at the seam between two sections of the spar case.
The video does not use the splinted-cabled air-beam scheme.
And

And splinted air beam burst test for loading:

And splinted air beam burst test for pressure at 1.3 bar (about 18.8 psi); performance would depend on spar case material and size and seam structure:

===========================================
Splinted air beam vs truss for the limited-performance -Dockweiler-Only Wing5 ... some, not all guessed advantages
Deployment
Air beam shape for immediate airfoil LE shape

[JoeF]

cogbelttiming.jpg (15.07 KiB) Viewed 1238 times

Compression element interface with spar case
Spanwise slippage of spar case relative to stations on the compression element(CE, CEL, CED) are unwanted.
Herein is described a method that avoids some disconcerting aspects of other methods.

Cog belt is bonded to the top of the compression element and a line of soft material is partnered
Semi-circular-cross-sectioned line of deformable material (foam, silicone, PU, etc. (many to be explored)) bonded to spar case. The apex of the semi-circle will be pressing against the cogs in the cog belt.
Some tiny elastic straps each 3 feet or so to temporarily hold CE, or an elastic pocket system may be employed, not sure of choice yet.

If tiny straps:
Open spar case; place CEwithCogs onto the line of soft material. Set the five or so tiny straps to hold positions until spar bladder is inflated. This method is simpler to construct than the next described method; I will be constructing both methods in order to compare matters.

If elastic pocket system is constructed, then the soft material is inside top of the pocket; the pocket is sewn to the spar case; the pocket is in segments to allow manual turning over of the CEwithCogs. The CEwithCogs is slid into the elastic pocket segments; once position is correct, turn the CEwithCogs over 180 degrees so that the cogs face the soft material. The elastic pocket firmly holds the CEwithCogs oriented. For packing up, turn the CEwithCogs over so the cogs no longer face the soft material; then slide the CEwithCogs out of the pocket for coiling for pack and tote.

While the bladder is inflated, the bladder presses the bottom of the CEwithCogs; then the cogs press into the line of soft material; the spar case is tensed; things hold in place. A terrific friction is obtained between the spar case and the CEwithCogs. Flight dynamics will find that that friction keeps the spar case and CEwithCogs in a firm or tight place-keeping union. Upon packing, the CEwithCogs easily separates from the spar case.

There are some interesting COTS printer timing belts that may fit the needs of the above method.
Adventure:
Hilitand 6mm Timing Belt 3D Printer Belt White GT2 Open Synchronous Belt PU with Steel Core 10M
https://nk-technics.com/at-pitch/pu-tim ... length.htm
Other COTS products may serve; investigation is ongoing.

Note: Other rough or spiky ribbons or belts will be explored; the timing belts are early contenders. I aim to avoid hook-and-loop methods.
===================
Potential of DIY ribbon of cogs or ribs? Yes, several ways.
E.g.: Base ribbon, then epoxy tiny ribs onto ribbon. Then bond the ribbed ribbon to the top of the CE. The labor of cutting and epoxy bonding the little ribs to the ribbon might be worth the effort.
E.g. ?: Bond a ribbon of coarse sandpaper to top of the CE ? Grit and wear experience will be observed and appraised. What grit will work best with what soft material? Adventure: https://www.bobvila.com/articles/2145-q ... sandpaper/
E.g. ? .... exploring ... Note: The combination of a certain soft material facing a certain grit will result in a specific experience. We do not want to wear out the soft material too soon!
Adventure: https://en.wikipedia.org/wiki/Toothed_belt
https://www.directindustry.com/prod/meg ... 37337.html
E.g.? chain, bead chain, Roller Blind Bead Chain Cord, one side of zipper not used as zipper, perforated ribbon, coarse twisted string, honeycomb ribbon, Sew Stitch On Gold Spike Stud Cone Flatback Punk Rock Trim mesh, Bead Craft (Gold Spike)Crystal Rhinestone Silver Ribbon ; mesh ribbon, brush tines cut and epoxied as ribs on flat ribbon--look for square tines; square wire; toothed belt; _____ :: Whatever selection, these would press into the opposing soft material to create friction; non-destructive bite is wanted. Avoid hook-and-loop as the packing labor is onerous.
E.g.?: Epoxy wet ribbon; place ribbon of screen on wet epoxy; cure; trim excess screen. Keep the ribbon with ribs of screen strands. Test.

CraftNetRibbons.jpg (221.49 KiB) Viewed 1235 times

[JoeF]

Small cuts of square wire bonded to a ribbon at intervals of maybe twice the width of the rectangular wire might well give a high friction against a bead of semi-circular cross-sectioned silicon. The edges of the square or rectangular wire would bite into the silicone. The short rib wire segments might be of aluminum.

RibbonOfCogsPresssSiliconeCompressionElementStabilizingPosition.png (7.72 KiB) Viewed 1226 times

==============
https://en.wikipedia.org/wiki/Warp_and_weft

[KaiMartin]

Small cuts of square wire bonded to a ribbon at intervals of maybe twice the width of the rectangular wire might well give a high friction against a bead of semi-circular cross-sectioned silicon. The edges of the square or rectangular wire would bite into the silicone. The short rib wire segments might be of aluminum.

The two parts are supposed to interlock geometrically. So the coefficient of friction may be less important. Note that a bicycle chain is lubricated to minimize friction. However, it does not jump from the gear (most of the time). Due to the interlocking geometry there is no need to press the chain on the gear.

How about 3D printing "teeth" on textile ribbon? At the right temperature the first layers of molten filament will bond properly with the ribbon. On top of this foundation the 3D printer can add any shape to provide the desired locking effect. I'd go for ribbons on both sides. This avoids the task of bonding mechanically loaded parts to a hard surface.

---<)kaimartin(>---

[JoeF]

Kai,
... ever interested in your insights! Thanks. As the variants are tried, I'll report details.
=================================

Presently I am appreciating a difference of uses of splinted air beams. Some uses require end-of-beam integration of compression elements. In a wing being considered, the wing-tip regions might not need the compression element present while letting the simple airbeam suffice. Most likely beam buckling regions of the spar: the compression element may be less than the span length. Strap lengths may be shorter. Some mass will be saved by the seen reduction.

LessCE.png (6.04 KiB) Viewed 1166 times

[Bob Kuczewski]

This video was recently posted to hanggliding.org:

https://youtu.be/V3CCCaVMDQY



I think It's a little longer than 5 feet, but it's close.

[JoeF]

Thanks, Bob!
Some sweet details show in the video. Hang from a point in the lower kingpost.... Clips. Detent button locking coupling. Keel strap. Limit strap for cross bar movement. And more. SS. Pitch-line course (reflex-keeping). 1.9 m = whisper below 6 ft 3 in. Some literature slip into writing "2 m" pack instead of 1.95 m. Perfex/ Lightfex The wiki tells of 1.95 m or about 6 ft 4 in.
I am not sure what model is shown in the video, Lightfex or the Perfex. Lightfex at 149 sq. ft. or Perfex at 170 sq ft.
https://en.wikipedia.org/wiki/Finsterwalder_Perfex
https://en.wikipedia.org/wiki/Finsterwalder
https://finsterwalder-charly.de/en/hang ... htfex.html
https://finsterwalder-charly.de/en/comp ... &Itemid=80
https://finsterwalder-charly.de/en/comp ... 102:perfex
https://finsterwalder-charly.de/en/hang ... ystem.html Snap-lock system




One might explore similar means using carbon fiber, lighter sail material, soft rigging lines, soft connections, and a bit more coupling to reach 5 ft packing, lower mass and ending with a tighter-use-to-Dockweiler-only purposing ....

Dockweiler sand would speak to the Perfex coupling tubes ...

[Bob Kuczewski]

1.9 m = whisper below 6 ft 3 in. Some literature slip into writing "2 m" pack instead of 1.95 m. Perfex/ Lightfex The wiki tells of 1.95 m or about 6 ft 4 in.
    :
One might explore similar means using carbon fiber, lighter sail material, soft rigging lines, soft connections, and a bit more coupling to reach 5 ft packing ...

"When all you have is a hammer, everything looks like a nail"

Maybe we're so focussed on an engineering solution that we're not seeing a potential administrative solution. Could you get a waiver for a 6 foot 4 inch carry on?

[JoeF]

     -----Some concerns surrounding the good comment, Bob:
1. Crowdedness on a city bus affects concerns.
2. Bus-rider perceptions of ominous-looking things matter.
3. Bus-driver decisions are probably final. Captain privileges...
4. I've not read of a length limit for city-bus packages in Los Angeles.
5. One page: https://www.metro.net/riding/guide/what ... ing-board/
6, There is a building of notes to camouflage a hang glider pack as a baby stroller or musical instrument or bicycle or common-appearing "luggage." But found in a forum: "Welcome to the LA forum. No, you cannot bring large pieces of luggage onto a city bus." The inquiring person wrote about a 62-inch sized piece of luggage. So, think two smaller pieces of luggage and the wearing of some HG parts. My experience concerns backpacks and bus drivers; if I look too big and threatening, then denial is probable. I aim to nearly "wear" the hang glider in pieces plus a non-threatening backpack while appearing stable and confident, not "lugging" along.
7. Appearing neat, clean, confident, happy, cordial, stable ... are part of the city-bus traveling aspects.
8. The effort for "5-ft" is a top point, not a bottom point; maybe the movement will come up with a 4-ft or 3-ft max-dimensioned pack.
9. https://www.metro.net/riding/go-bike/bike-transit/
10. People regularly carry just-purchased products and groceries. Bus drivers have frequently allowed large bags of recyclables carried by some riders. Abuses have been sometimes permitted.
11. Two smallish carry-ons plus some system parts worn nearly as clothes plus a non-threatening backpack might be someone's solution to the topic's challenge.
12. Stiff-leggedness (beams strapped to legs)?
13. I have seen permitted fishing rods sans hanging hooks go on city buses.
14. Wing5 might end up being less than 5-ft long; maybe 4-ft or 3-ft. Sail might be worn on body. Skinny non-ostentatious backpacking might occur. Telescoping or angle nesting might occur. Segmented beam parts under clothes might occur.
15. Aim to stay standing while riding the bus, perhaps.
16. If backdoor boarding is allowed, then choose that option, so as not to bother the bus driver.
17. Perhaps hide some parts near the flying site; such parts would not have to be carried on the bus. Fence posts? Buried beams? ??? Near-site-walking-distance storage? Last bus-departure point to flying site might offer up some storage-of-parts opportunities.
18. What beams may be resolved into telescoping affairs or nesting-angles affairs?
19. Have a simple explanatory card with a photograph that indicates what is being carried. Offer such to fearful or inquiring riders or drivers.
20. Master couplers.
21. Waivers may be overcome by drivers.
22. One is still liable for hitting or injuring passengers with one's body and carried objects. Length, mass, controllability, stability, sharpness, leverage, etc. play here. Many bus riders are ever watching that they not be touched, hit, pushed, or endangered in any way. And I do want to avoid such onslaughts to riders.
23. All this bus talk might invite meditations about: a) Getting a car. b) Forming the hang glider into an electric bicycle solar-charged. c) Coordinating with friends who are going to the flying site. d) Soaring from home to the flying site. e) Buying storage space at Dockweiler (not available, so it seems). f) Buying storage space in walking distance to the flying site. g) Buying a home within walking distance to the flying site. h) Bus travel with friend; split the carry-on challenge between two or more persons. i) Hiding some parts within walking distance of the flying site. j) ?????