[JoeF]

The following note continues the option stream for connecting cross lines to the spar of some TPHG. See some other options in prior posts. Further options are invited from anyone in the world.

My free ChatGP{T did not like my long prompt; it rejected it three times. Then I put in the same long prompt again and the ChatGPT coughed out a reply which see below:

1. Spar Segment Terminology and Structure
- Mother Tube: The larger spar segment that receives the smaller segment.
- Child Tube: The smaller spar segment that inserts into the mother tube.
- Meta Spar: A spar constructed from multiple nested spar segments.
- Root Tube: The initial segment in the meta spar assembly.
- Tip Tube: The final segment, which only acts as a child tube.

2. Assembly Process Overview
- Joe Cup: A flanged bushing that facilitates the connection between mother and child tubes.
- Flange: The flange of the Joe Cup sits on the end of the mother tube but does not extend over the child tube.
- Insertion Limit: The Joe Cup has a bottom that limits how far the child tube can be inserted into the mother tube.
- Function: The Joe Cup’s long body fills the gap between the mother and child tubes, eliminating wobble and ensuring a stable connection.

3. Specialized Sleeve for Spar Assembly
- Purpose: To aid in the assembly and later tensioning of cross lines after the sail sock is mounted.
- Positioning: The sleeve is placed over the child tube and slid away from the child’s insertion end by about 5 inches before joining the spar segments.
- Branching Lines: The sleeve has two lines branching out, each terminating in a button loop.
- Button Loop: A small loop designed to receive an oblong button attached to a cross line.

4. Assembly Sequence
a. Meta Spar Assembly:
- The root tube receives the second tube, which acts as a child.
- The second tube then serves as the mother for the third tube.
- This process continues until the final (tip) tube, which only serves as a child.
- Each connection involves inserting the child tube into the mother tube, with the Joe Cup providing the stable junction.

b. Sleeve Positioning:
- Position the specialized sleeve on the child tube.
- Slide the sleeve 5 inches away from the insertion end to allow for proper joining.
- Ensure the sleeve is correctly aligned for later access through the sail sock.

5. Cross Line Tensioning and Buttoning
- Sail Sock Installation: After the meta spar is assembled, the sail sock is placed over the frame.
- Accessing Button Loops: Small windows in the sail sock allow access to the button loops on the specialized sleeves.
- Cross Line Attachment:
- Fetch the button loops through the sail sock windows.
- Attach the cross line by inserting the oblong button through the button loop.
- Apply tension to the cross line to secure the button in place.
- Repeat for all cross lines, ensuring each is properly secured.

6. Disassembly Process
a. Relaxing Cross Lines:
- After flight, relax the tension on the cross lines.
- Unbutton the cross lines from the button loops.
- Pack the cross lines as per the TPHG manual.

b. Sleeve and Joe Cup Removal:
- Once the sail sock is removed, slide the specialized sleeves off the spar segments.
- Withdraw the Joe Cups from the spar segments and store them as designed.

c. Nesting Spar Segments:
- With the sleeves and Joe Cups removed, the spar segments can be nested for compact packing.
- Ensure that any end plugs used for joining remain in place or are removed as required.

7. Suggestions and Considerations
- Window Placement in Sail Sock: Carefully plan the positioning of the windows in the sail sock to ensure easy access to the button loops.
- Button and Loop Durability: Ensure that the materials used for buttons, loops, and cross lines are durable enough to withstand repeated use and tension during flight.
- Assembly Efficiency: Consider developing a standardized procedure or checklist for the assembly process to minimize errors and streamline setup.
- TPHG Manual: The manual should include detailed instructions and diagrams for both assembly and disassembly, as well as guidelines for packing the spar segments, sail socks, cross lines, sleeves, and Joe Cups.

What did not get treated in the above was the deal that the specialized sleeve would slide a bit to butt against the end of the Joe Cup at the end of the inboard end of a mother tube. During flight loading that butting would be firm as the rigging cross line pulls the sleeve inboard but is stopped by the Joe Cup and end of the mother tube end. The sail sock keeps some inboard axial compression on the meta spar(s) that assures children stay with their mothers.
Note: Certainly we do not want the button to break during flight, so the design of the button will be important.

The specialized sleeve with two branching lines has not been explored deeply yet. I want it to be low mass, mostly flexible in pack mode to keep low volume. The sleeve will be firmly pulled into butting the top of the adjacent Joe Cup and thus pressing on the end of the adjacent mother tube's end. Keep in mind that the sleeve would only directly touch the top rim of the Joe Cup as the Joe Cup is covering the end of the mother tube.

[JoeF]

DENSIFICATION
A key theme for the TPHG movement is "densification" of the hang glider parts for low volume packing. What can you say about such process?

The concept of "densification" in the context of the TPHG (Tiny Packed Hang Glider) movement revolves around maximizing the packing efficiency of hang glider parts to achieve the smallest possible volume. This process is crucial for enhancing the portability and convenience of hang gliders, especially in urban settings where compact transport is essential.

Key Aspects of Densification:

1. Telescopic Spars:
- Nesting Segments: By designing spars with telescoping segments that can nest within each other, the overall length and volume of the packed glider are significantly reduced. Each segment fits into the next larger one, creating a compact bundle.
- Material Selection: The use of lightweight, strong materials like carbon fiber for the spar segments allows for thinner walls and tighter nesting, contributing to lower packing volume.

2. Collapsible Components:
- Modular Assembly: Components that can be disassembled into smaller parts or folded down contribute to densification. For example, using couplers or sleeves that allow for easy assembly and disassembly helps minimize the size of the packed glider.
- Flexible Hinges: Hinges and joints that allow parts to fold or collapse, such as compression sticks that fold or wings that can be rolled or packed flat, also contribute to densification.

3. Sail and Sock Packing:
- Compact Folding Techniques: The sail or wing sock material must be folded or rolled in a way that minimizes creases while allowing for tight packing. Using materials that are both durable and flexible helps in achieving a smaller packed size.
- Airfoil and Washout Considerations: Even though the sail or sock needs to be packed tightly, it must be able to return to its aerodynamic shape during assembly, with airfoil shape and washout being key performance factors.

4. Connector and Coupler Design:
- Minimal Bulk: Connectors, couplers, and fittings should be designed to add minimal bulk. They must be lightweight, strong, and designed to allow for the tightest possible nesting or packing of segments.
- Exterior vs. Interior Couplers: Choosing exterior couplers that don’t interfere with nesting or exploring "Joe Cups" or other innovative joining methods that reduce overall packed length can enhance densification.

5. Innovative Packing Strategies:
- Volume Optimization: The overall packing strategy should be optimized, considering how each component fits together. For instance, combining certain components into single bundles rather than packing them separately can reduce dead space and overall volume.
- Use of Compression Bags or Containers: Similar to how sleeping bags are compressed, the use of compression bags or containers could help reduce the volume of softer components like sails or socks.

Benefits of Densification:
- Ease of Transport: A more densely packed hang glider is easier to carry, store, and transport, particularly in urban environments where space is limited.
- Reduced Weight: Densification often goes hand-in-hand with weight reduction, making the glider easier to handle and potentially improving flight performance.
- Urban Mobility: The ability to pack a hang glider into a compact form makes it more feasible for pilots to use public transportation or even bicycles to get to and from flying sites.

In summary, densification in the TPHG movement is a process focused on reducing the physical size of packed hang glider parts to achieve maximum portability without compromising the structural integrity or performance of the glider. This process involves innovative design, material selection, and packing strategies to enable pilots to carry their gliders conveniently in urban settings.

[JoeF]

Zippered Sail Segmentation

Prompt:
Could judicious zippering of sail segments allow crease-free tight packing of hang glider sails?

Response:
Yes, judicious zippering of sail segments could indeed facilitate crease-free tight packing of hang glider sails. Here’s how it could work:

1. Segmented Design: By dividing the sail into smaller, zippered segments, each segment can be packed separately and then zipped together during assembly. This approach would prevent large folds and creases that typically occur when packing a full-sized sail.
   
2. Controlled Folding: Zippered segments could allow for controlled folding or rolling of each piece, minimizing stress points and ensuring a more uniform pack. For example, each segment could be folded along natural lines of tension, reducing the risk of creating creases that could weaken the fabric over time.
   
3. Adjustable Tension: After assembly, zippers could be used to adjust the tension of the sail segments, allowing for a tighter and smoother sail surface. This would ensure that the sail maintains its aerodynamic properties without the wrinkles that could occur with a single-piece sail.
   
4. Compact Packing: With segmented sails, the individual pieces could be nested or layered in a way that maximizes space efficiency, leading to a more compact pack. This could be particularly advantageous for urban transportation, where minimizing the overall volume is crucial.
   
5. Maintenance and Replacement: Zippered sails would also make it easier to replace or repair individual segments without having to deal with the entire sail, potentially extending the life of the glider.

In summary, incorporating zippers into the sail design could allow for a more modular approach to packing and assembly, reducing the likelihood of creases and enhancing the longevity and performance of the hang glider.

[JoeF]

Rolling sail segments around cores is a practical approach to maintaining a wrinkle-free surface in TPHG sails. When sails are rolled instead of folded, the fabric experiences less creasing and stress, which can lead to wrinkles that are difficult to remove. The use of cores helps in maintaining a consistent roll, ensuring that the sail material is evenly distributed without tight spots that could cause damage or distortion. This method is particularly useful for TPHG sails, which require precise handling to maintain their aerodynamic properties. Additionally, rolling the sails makes storage more efficient, as the sails can be packed into a smaller space without compromising their integrity.

Gemini AI suggested from a prompt, not optimal, just teasing.

GeminiGenerated001.jpg (69.93 KiB) Viewed 586 times

In one option being studied: 8 sail segments, 7 zippers to have the meta sail. Wrap first segment snuggly without wrinkle, then the next segment, etc. Presto: no wrinkles.

[JoeF]

https://chatgpt.com/share/975a7935-9f53-4b05-afd4-a89c438574c5
Mulling TPHG CF tube curing with ChatGPT.

================

=================

What is the world record for low-volume TPHG tote volume?
ChatGPT said:
ChatGPT
The world record for the lowest-volume tote for a Tiny Packed Hang Glider (TPHG) isn't officially documented, as it can be quite specific to the design and goals of individual projects. However, hang glider designers and enthusiasts often aim for the smallest possible packed volume to facilitate urban transportation and ease of carrying.

In general, for compact hang gliders, the packed volume can be minimized by optimizing the telescopic spar design, using lightweight materials, and employing innovative packing methods. Achieving a 4-foot packed length is a common target for designs focused on urban mobility.

If you're aiming for a record or benchmark, you might want to compare your design with existing compact hang gliders or check with hang gliding communities and forums for any unofficial records or notable achievements.

=====================

[JoeF]

Hybrid, mixed technologies?
Main spars and keel: rigid beams.
Most ribs: separate inflated ribs. For tote: deflate the ribs and perhaps wear them as belts; or tote them compactly in other ways.
=================
Filler:
Not sure if link works: https://youtube.com/shorts/3tkPz5BM33s?si=zsXTSzl2QXeksfdc
A tiny glider ...

[JoeF]

One source for TPHG movement design:

[JoeF]

Steel tubing, thin-walled? How might steel compete in the TPHG realm? Incomplete studies of how thin-wall steel might win some targets in TPHG just might be unfortunate. Aluminum and CF tubes compete. Low volume packing and weight and durability are playing their games among the material choices. Wanted: experiences and expert engineering designing. Tradeoffs? Time will tell.

[JoeF]

Development note on one type of TPHG being carefully approached:

Your Prompt:

I think that I can get all 22 tubes of a TPHG into two telescopic nests for tote. Here is how: Left wing fore spar segments and left wing aft spar segments can come from one telescopic nest by alternating sizes: ACEG for fore spar left and BDFH for aft left spar. Similar for the right wing's fore and aft spars. That accounts for 16 tubes of 4 ft. length. Then the two main keel tubes just fit over the two A's for tote; the third keel tube for tailing could be an "I" (letter i for symbol of the tube sized smaller than the H tube for the telescopic tote scene) tube telescoping into H. We cared for 19 tubes thusly. Now, how about the kingpost and two queenposts; the kingpost could be as "I"; and then the two queenposts could be heavier walled as Js in the telescopic stack.

Response:

Your plan for packing the 22 tubes of your TPHG into two telescopic nests is a clever and efficient approach. Here's a breakdown of how your idea works:

1. Left Wing Spars:
- Fore Spar Segments: A, C, E, G
- Aft Spar Segments: B, D, F, H

2. Right Wing Spars:
- Fore Spar Segments: A, C, E, G
- Aft Spar Segments: B, D, F, H

3. Main Keel Tubes:
- Two main keel tubes (larger in diameter) fit over the two A segments when nested.
- A third keel tube (tailing tube) designated as "I" fits into the H segment.

4. Kingpost and Queenposts:
- Kingpost: The "I" tube, which is smaller in diameter and fits into H.
- Queenposts: Two queenposts designated as "J" tubes, which are slightly larger and heavier-walled, fit into the nested stack.

Summary of the Nesting Strategy for Tote:

- 16 Wing Spar Segments: Nest in two groups of eight (A, B, C, D, E, F, G, H).
- 2 Main Keel Tubes: Fit over the two A segments in each group.
- 1 Tailing Keel Tube (I): Fits into the H segment.
- 1 Kingpost (I): Shares size with the tailing keel tube.
- 2 Queenposts (J): Heavier-walled, nesting into the telescopic stack.

This nesting strategy allows you to compactly pack all 22 tubes into two telescopic nests, which should be manageable for transport. The alternating sizes between fore and aft spar segments is a smart way to maximize space and maintain structural integrity while keeping the design lightweight and portable.

If the wall thickness and diameter of the tubes are well-coordinated, this setup should work efficiently. The inclusion of the heavier-walled queenposts as "J" tubes in the telescopic stack adds a thoughtful touch for maintaining strength without adding excessive bulk.

Note of options in the above scheme: The two queenposts might be sized swapped into a different point of the sequence: ABCDEFGHIJ. And there is the option to have the kingpost in a modified place in the sequence. And if the queenposts and kingpost are to be three-segmented items, the the central segment of each three segments could in the sequence while the two end segments of the posts might be toted as 12" items separate from the two big-series toted items; so, there could be 6 of those end tubes; solutions and uses of those six (6) end tubes of 12 inches in length are not described in this note. The challenge of ribs is not addressed in this development note. Rigging line sets and Joe Cups are not dealt with in this post. Sail segments might be rolled smoothly around the two described telescopic nests of tubes. It would be a joy to have the primary tube-and-sail-pack of a TPHG tote be with a cross section of a 3"x 5" card ... and 4 ft long. Less than a 1/2 cu ft volume!

This post anticipates inflated ribs; the deflated toted ribs might tote as body wraps; or they could roll on the main pack.

Note of options in the above scheme: The two queenposts might be sized swapped into a different point of the sequence: ABCDEFGHIJ. And there is the option to have the kingpost in a modified place in the sequence.

And if the queenposts and kingpost are to be three-segmented items, then the central segment of each three segments could be in the sequence, while the two end segments of the posts might be toted as 12" items separate from the two big-series toted items. So, there could be 6 of those end tubes. Solutions and uses of those six (6) end tubes of 12 inches in length are not described in this note.

The challenge of ribs is not addressed in this development note. Rigging line sets and Joe Cups are not dealt with in this post. Sail segments might be rolled smoothly around the two described telescopic nests of tubes.

It would be a joy to have the primary tube-and-sail-pack of a TPHG tote be with a cross section of a 3"x 5" card ... and 4 ft long. Less than a 1/2 cu ft tote's pack volume!

[Bob Kuczewski]

How to use a hacksaw (56 second video)

https://youtu.be/-BdLo8UfOSk