[JoeF]

Has anyone else noticed something fishy about that little ruler that has shown up in recent thread images?
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Development note:
Frequently CF has entered HG for the high performance wing helping to lower drag by removing some need for exterior geometry-keeping rigging lines. Now consider for different aims the use of CF while keeping rigging that employs exterior geometry-keeping lines. The potential result is a lower empty weight lower-performance wing; when the lower-performance is acceptable for some reason, then the lower empty weight and perhaps lower pack volume would be wins. Lowering wing empty weight and lowering pack volume while staying fully bus-polite forms the target of one faction of the TPHG Movement; there are other competing factions in the movement.

Development Note:

Carbon fiber (CF) has often been integrated into hang gliders (HG) to enhance high-performance wings, primarily by reducing drag through the elimination of some exterior geometry-keeping rigging lines. However, let's consider a different approach where CF is used while retaining the exterior geometry-keeping lines. This could result in a lower empty weight, albeit lower performance, wing.

When a lower performance level is acceptable for certain applications, the benefits of a lighter empty weight and potentially reduced pack volume become significant advantages. Achieving these benefits while maintaining a fully bus-polite design aligns with the goals of one faction within the Tiny-Packed Hang Glider (TPHG) Movement. Other factions within the movement may have different priorities and objectives.

Lowering the wing's empty weight and minimizing pack volume while ensuring the glider remains convenient for public transportation are key targets for this faction. Balancing these factors could lead to significant advancements in the TPHG Movement's objectives.

[JoeF]

Development Note for Some TPHGs

Internal Couplers in Spar Assemblies Holding a Five-Branched Component of Line Items

Internal couplers, located between the wing tip and the keel in spar assemblies, play a crucial role in some TPHG designs. These couplers connect the ends of two separate spar segments and can serve as the base for four lines: the flying line, the landing line, and two stabilizing diagonal lines within the wing's framing. These diagonal lines help form framed quadrilaterals, consisting of fore and aft spar segments and chordwise ribs or chord struts.

A key aspect of this development is the bonding of a loop to the coupler, which features four branching short lines, each terminated with pigtailed loops. This design emphasizes the importance of securely bonding the five-branched component to the coupler. The foundational branch would fully wrap around the spar coupler, with the wrap bonded to the coupler for enhanced stability and durability.

For transportation during hikes or bus rides, each coupler would have its own designated bag or pocket for easy and organized storage.

[JoeF]

Development note related to the above post's coupler remarks:
Keel Fore Spar and Keel Aft Spar Couplers Bonding with Components of Loops
The nose coupler and aft-spar couplers could have bonded to them a component of loops. The count of loops with pigtails could be five while having the bonded loop occur. The six branches of the component serve as follows: one branch is well bonded to the coupler; then the other branches are functioned as follows: two loops handle the crosslines through the base of the two queenposts; two handle diagonals of wing's framing quadrilaterals, and one handles the landing line through the kingpost.

Development Note: Keel Fore Spar and Keel Aft Spar Couplers Bonding with Components of Loops

The nose coupler and aft-spar couplers could be enhanced by bonding them with loop components. Specifically, each coupler could integrate five loops with pigtails. Here's the proposed function of these loops:

One loop without any pigtail is securely bonded to the coupler itself.
Two loops with pigtails manage the crosslines through the base of the two queenposts.
Two loops loops with pigtails support the diagonals of the wing’s framing quadrilaterals.
One loop with pigtail handles the landing line through the kingpost.
This setup aims to streamline the attachment and tensioning process, providing a robust and organized configuration for the TPHG structure.

The branches of pigtailed loops are sized to allow easy lark's head knot holding of a functional line's end stop knots.

Note: In some versions of some TPHG using such as the above, it might turn out that a simplification may occur in one way or another. Could the diagonal lines that help keep quadrilaterals stable in shape be simply neglected, or maybe be simply permanently connected to the couplers, or maybe just half-permanently connected awaiting the other half to connect during wing assembly.

These questions may be worked out by playing with models and practicing assembly and disassembly. If "neglected" then a synergy with compression ribs and spar segments and sock sail might preclude the use of frame quadrilateral diagonal stays. Locking the sock sail to the frame may well be adequate for staying the shape of the quadrilateral presented in the wing framing. If there are no quadrilateral diagonal stays, then that could reduce the number of lark's heads needed to firm the wing.

[JoeF]

In the city’s heartbeat, we take flight,
A dream of wings, compact and light.
Telescopic spar, our guiding star,
From bustling streets to skies afar.

Folded small, our gear in packs,
On city buses, no weight on backs.
With chest packs, arm packs, head-hat packs,
We journey forth, leaving no tracks.

Dyneema threads and carbon gleam,
In our tiny packs, we trust our dream.
Magnetic thrust and ribbon's spin,
We conquer skies, the winds we win.

Coiled tapes and hinged arcs blend,
Forming beams that never bend.
A triangular prism, strong and tight,
Disassembled, takes to flight.

From magic carpets to modern glide,
Our hang gliders spread wings wide.
Aerovelo’s lessons in our mind,
A fusion of old and new combined.

City's hum and whispering breeze,
We soar above, with graceful ease.
Busable-packed, our movement's crest,
In urban skies, we find our quest.

[Bob Kuczewski]

A triangular prism, strong and tight,
Disassembled, takes to flight.

If that was written by ChatGPT, I think it shows one of its flaws. A disassembled glider does not (normally) take to flight in any desirable way. A better passage might be:

A triangular prism, strong and tight,
Once assembled, takes to flight.

It's possible that ChatGPT's "word-salad" view of our language didn't fully comprehend what it was saying. But that will change.

[JoeF]

The ChatGPT makes errors ---- and for serious matters needs due diligent checking. Thanks for some of that checking, BobK.

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Development Note On Setting Sock Sail To Avoid Quadrilaterals' Stay Lines
Anti-slip treatments for the inner surface of the wing sock that is likely to rub on aft spar?
Set left and right socks over two-spar wings. Zipper left and right socks over the keel.
Have on spar coupler shallow knobbing to match reinforced slots in the sail sock; the slot will register over the knobbing.
Once the compression ribs do their job of tautening the sail sock, the sail sock will make unnecessary frame quadrilateral diagonal stay lines.

A ChatGPT massage over a short discussion I had with the large language model (LLM) program:

Development Note On Setting Sock Sail To Avoid Quadrilaterals' Stay Lines

Set the Left and Right Socks: Place the left and right sail socks over the two-spar wings.
Zipper the Socks: Secure the left and right sail socks together over the keel using a sturdy zipper.
Spar Coupler Integration: Add shallow knobs on the spar couplers that match reinforced slots in the sail sock. These slots will fit over the knobs to provide stability.
Compression Ribs: Insert compression ribs through small access windows in the sail socks. Secure the front end of the ribs to the fore spar, then press the aft end onto the aft spar. This will tension the sail sock effectively.
Achieve Tautness: Once the compression ribs are in place, they will tension the sail sock, making frame quadrilateral diagonal stay lines unnecessary.
This setup aims to maintain a taut and aerodynamic sail without additional stay lines, thanks to the combined tensioning effect of the spars and ribs.

[JoeF]

Development Note Regarding Compression Rib Terminals

T Fitting Concept

Consider the potential of incorporating a T fitting into the fore and aft ends of a compression rib. The design would feature:

Head of the T: Approximately 2 inches wide with a cross-section resembling a semi-circle. The inner face of this curved head would be cushioned.
Stem of the T: This section would couple with the end of the rib.
tThe broad head of the T fitting is intended to distribute the pressure across the spar segments effectively.
The sock sail would limit the rotation of the two T fittings of each compression rib. The compression ribs would not be in sail pockets, but interior of the sock. This might be inviting experiments with rib density and rib positioning.

--

[JoeF]

Development Note on Free Compression Rib That spreads Fore and Aft Spar and Thus Making Sail Sock Taut and Cambered

Have the rib made of four parts: two special T terminals, fore camber-forming part, aft straight shaft.
When pressing the rib into place, the fore camber-forming part bends up to form some caber in the sock sail's upper fabric.
To assemble or disassemble the rib, the aft rib terminal may slide sideways to get relief at disassembly; at assembly the aft terminal may slide sideways into final position. Concern for adjusting rib length may be addressed in other development notes.

[JoeF]

For study looking for clues potentially applicable to the TPHG movement:
http://m-sandlin.info/
http://m-sandlin.info/xgliders/xgliders.htm

" ... long live tiny-packed hang gliders."
First, let's get some going ....

[JoeF]

Handy Glider
https://youtube.com/shorts/x-OK8DSxpgE? ... CNkG-VSQ9k
and
https://youtube.com/shorts/cx2jT1VvzXA? ... iZ8UfoN_aA

Metaphors for TPHG ways and means?