[JoeF]

Assembly focus for this comment regards the matters at the outboard tip of the most outboard compression element.[/b]

Have the spanwise webbing that is sewn well to the spar case be sewn also to the hook tape be with extra length of say 5 inches. On that extra length of webbing sew Dual Lock for say 4 inches of length; match the Dual Lock by bonding say 5 inches length of Dual Lock on the interior face of the CE segment. Wrap the exterior loading tension strap around the end of the CE: then wrap the webbing excess atop the exterior loading tension strap and seat the Dual Lock.

3TipOfCEaffairWing5option.png (28.01 KiB) Viewed 1263 times

[JoeF]

Air pump for Wing 5 in first era of efforts: Titan Air Pump

Wing5TitanPump.jpg (17.9 KiB) Viewed 1258 times

Air pump
Investment made.
Purchased Red Paddle Co Titan Pump (first, not the II) ... (having yet no recommendation about the item). Arrives in about a week.
This will be carried to the site on the bus along with the packed Wing5, day's extras, helmet, harness. The pump over time will need some maintenance.

Looking into adding to the pump a thin lower platform, axle and wheels and maybe thus have the pump double as a light hand truck; this will be explored, else the pump might be second luggage or backpack item. The 5 lb will not be part of the flying machine From bus to Dockweiler is a relaxing firm substantial walk; wheeling the Wing5 pack from bus arrival to the actual flying site is the aim here.

Inside the bus, the pump will either be in the Wing5 pack or backpacked or held as a second visible luggage item.

Want to inflate the spar? Be my guest ...

[dhmartens]

Former Senator Harry Reid tells a story that says the machine you seek is in our possession.
Getting our hands on it and machining it into a 5 foot packed personal flight hang glider is another matter.
Michio Kaku has said the release of such a device into our civilization could cause its collapse within 30 to 90 days just like it did when the Bronze age Aztecs encountered the Spanish who were 500 years more advanced.
Until we get our hands on one, the paragliders will continue to dominate the sport.

I think Harry Reid said it was here: At Lockeed Martin
https://www.google.com/maps/place/Lockh ... 18.1161116

https://www.youtube.com/watch?v=UuYCa-65hhI
https://www.youtube.com/watch?v=euU0WV6co9A
https://nypost.com/2021/04/30/former-se ... fragments/

[JoeF]

In some worlds: PGs are not part of the sport of airframed hang gliding.... huge difference. Only airframed hang gliders dominate the sport of airframed hang gliding.

Materials and design will continue to bring forward hang gliders dedicated to certain niche flight realms.

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Five bladders for model work toward Wing5 matters:
Helmet and toy toss disk shown. No spar cases or compression members for models yet. Soon.

AugustFiveModelBladders.jpg (154.2 KiB) Viewed 1236 times

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Notes toward iteration one of Wing5:
Looks like the compression members will go on the exterior of the spar cases.
And the compression member assembly will sandwich the spar case with an interior stand-off complex finished by an interior strap of tensioned Dyneema strap. Dual Lock will probably be used exteriorly and coin hook and loop on the interior. The strap will grab the ends of the compression element of spars. There will be a spar for left wing and spar for right wing; abandoning single-spar approach for iteration one.
Approximate 13 ft of compression element per spar; the compression element will not go to the wing tip; I will see how such goes.

The stand-off complex will mix wood and rigid foam parts of about 3-ft lengths; bond the short wood standoffs with bars of rigid foam. The Dyneema strap will ride on the interior face of such complex sticks. Strap will not be bonded to the stand-off sticks.

[JoeF]

Lateral use of the model bladder: Stick the inflated bladder into the sand at Dockweiler for a marker or wind-tell holder or soft-S pylon or flight-territory corner marker. Also: the item can be a toss toy alone or with someone else.
===========================================================================
Iteration one of Wing5 looks like it will feature the following compression-element coupler:
Rectangular tubing with an interior stop bonded. Adjacent compression element will press against the interior stop of the coupler. The left wing spar will feature three (3) couplers for coupling four (4) compression elements. Dual Lock will not be on the coupler's face; but the exposed face that has no coupler material that faces the spar case will have Dual Lock. The spar case will have matching Dual Lock in matching spaces.

CouplerPlugBonded.png (7.21 KiB) Viewed 1231 times

As build comes closer, it appears that 3.5 ft pack will arrive rather than the 3 ft. 4x3.5=14 ft; a foot without compression element may sustain at the wing tips where pinch closure will be employed to give foundation for tip rib. Keel end of the two spars will have spar case closed with end disk of fabric.

SidedWing15feet.png (18.44 KiB) Viewed 1231 times

[KaiMartin]

Hi Joe.
Your detailed reports finally taught me the principle of operation of "tensairity". Somehow I got the impression that tensairity is all about ropes that wrap an inflated tube in a special way. Gut feelings insisted that tension ropes alone would not be able to dramatically stabilize an inflated tube. So I thought, this was some kind of clever marketing or even snake oil. With the presence of a beam the concept suddenly makes much more sense

The leading edge tubes of a hang conventional glider need to resist bending in the horizontal plane, to prevent excessive washout. Hence the struts of the early gliders. Maybe, the inflated spar should be equipped with a second compression beam to counter these forces.
Radical Alternative: Place the spar at about 1/4 of the chord. Half of the lift would be acting in front of the spar. Consequently, the bending forces would cancel. The spar could get away with much less horizontal stiffness.

---<)kaimartin(>---

[Frank Colver]

Joe, this isn't about 5' packed gliders but I hope you are also following the thread about short packed gliders for transport that has been running on hanggliding.org

One recent photo there reminds me of the Porta Wing with the guy having his short packed glider on his back.

Here is the HG.org short packed topic link:

https://forum.hanggliding.org/viewtopic ... 14#p411114

Frank

[JoeF]

Kai and Frank,

Frank, thanks for the link. In our topic we have spread some of the same link. Eddie's backpack was shorter than the FunFex pack.

Kai,
In my posts, see "CED" or compress-element drag
for the drag deal you rehearse. Good noticing. Spars play to carry both lift and drag. My first iteration of Wing5 will have only the CEL and will use bowsprit drag lines to carry the horizontal drag; the inflated spar case itself will carry some of the drag load also. I will first avoid having two CEs, so just the CEL for iteration one.

New notice for Wing5 iteration one: bowsprit keel extension will be the aim; three section of the keel tube with two coupling points are anticipated. Three drag lines from the front of the bowsprit per side wing will be explored; the dirtied air will be tolerated in lieu of have in the spar case a CED.
===============================

[KaiMartin]

Spars play to carry both lift and drag.

Ah, now I understand the naming scheme.

A quick estimate of the drag load of the spar:

• Drag without drag contributed down tubes, base the pilot and most wires does not pull on the spars. So these can be omited. Side wires are an exception. Half of their drag applies to the spars. However, their contribution is surely minor compared to the rest of the wing.
• At best glide the lift-to-drag coefficient C_LD of the pure wing is probably about 25.
• In quasi stationary flight lift exactly compensates the weight of the system. To keep numbers simple, I put the mass of pilot plus wing at 100 kg. This implies about 1000 Newtons of lift (gravitional constant assumed to be g=10 ).
• With C_LD = 25 and total lift at about 1000 Newton, the drag that the spar needs to resist, is about 40 Newtons.
• Drag distributes symmetrically to both sides of the wing. So each side needs to take about 20 Newtons of drag. This is equivalent to about 2 kg of mass hanging at half the length of the spar.
• At speed C_LD tanks. Consequently, the drag load of the spar increases. C_LD = 5 seems to be a reasonable minimum. This translates into a 10 kg load to each half of the spar.

This is more than I thought it would be. It probably accounts for the infamous deformed wing at higher speeds.

---<>)kaimartin(>---

[Bob Kuczewski]

A quick estimate of the drag load of the spar:

Thanks for that clear explanation. I followed it up until the translation from wing drag to equivalent mass hanging at mid-spar:

• ... each side needs to take about 20 Newtons of drag. This is equivalent to about 2 kg of mass hanging at half the length of the spar.

I'm not familiar with that relationship. Is it a rule of thumb or is there some more explanation that can help show that relationship?

Thanks in advance, and thanks for sharing your expertise.