[Semper Fidelis]

What "tube" for your TPHG 4.6 is being milled?

Milling the tubes, a nightmare !

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From 8:00 AM to 1:30 AM two on the machine for the geometry , tubes in 7075

[JoeF]

Congratulations on the tube-milling progress for tube-joining for your TPHG 4.6 project!
With you, we still seek historical notes on the 5 ft 1 in production deal that you have mentioned.
I've no new guess on the shadow-part puzzlement yet.
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Development note as I present to AI and get responses over my inputs:
Design Overview:
1. Compression Rib Structure:
- Three Carbon Fiber Tubes:
- Central tube with two outer tubes inserted into each end.
- Joining Mechanism:
- One tube is joined to the central tube using a standard Joe Cup.
- The other tube is connected via an elastic Joe Cup, adding flexibility.

2. Pressure-Spreading End Pieces:
- Hinged Triangle Flats:
- Two flat equilateral triangle pieces, hinged at one vertex, form a stem that inserts into the outer end of the rib's tube.
- These triangles spread the pressure across a wider area of the spar, reducing point stress.
- Fabric Webbing:
- A fabric web bridges the two triangles at the edges that interface with the spar.
- This fabric creates a "hammock" effect, evenly distributing pressure across about 40% of the spar's circumference.
- The webbing is securely bonded to the triangles, ensuring stability and even load distribution.
- Detachable Design:
- The pressure-spreading feet can be removed from the rib subassembly for compact packing, with the hinged triangles folding flat for easy transport.

Assembly Process:
- The two spars are first placed inside the sail sock.
- A prepared compression rib, with the end pieces attached, is then depressed to fit one end against the fore spar and the other against the aft spar.
- The fabric-webbed triangles ensure the pressure is evenly spread, maintaining the integrity of the spars and the tautness of the sail sock.

Benefits:
- Tool-Free Assembly/Disassembly: The design allows for quick and easy assembly without the need for tools, making it convenient for transport and storage.
- Pressure Distribution: The use of hinged triangle flats with fabric webbing effectively spreads the load, reducing wear on the spars and ensuring a more durable and reliable structure.
- Compactness: The ability to fold the pressure-spreading feet and disassemble the compression ribs makes the hang glider highly portable.

This design seems well-suited for your TPHG, balancing the need for structural integrity with the convenience of portability. The use of Joe Cups and elastic Joe Cups allows for flexibility, while the pressure-spreading mechanism reduces stress on critical components.

[JoeF]

This development note has a focus on one type of potential TPHG. The type feature two spar sets: left wing two spars, right wing two spars. The spar segments are "nestable" during pack and tote, with the spar set count of two. This notes does not deal with the ribs, keel, kingpost, or two downtubes (queenposts). Herein we focus on a special opportunity of getting 16 spar segments into just two packed nesting. Let capital letters denote in natural order the larger OD tube, so "A" would be the larger spar segment followed by B, C, etc. ABCDEFGH in pack for tote is one spar set fully nested into each other; assume for now each spar segment is simple, not tapered in itself; high technology might deal with taper or double-taper for one spar segment, but a more economical route would be where each spar segment is for itself with a constant OD and constant ID. So, this note would see a packing where one finds the two spar sets: ABCDEFGH and ABCDEFGH. Thus in pack one would see externally: OO where we let O represent a set of spar segments exteriorly seen as AA, but deep inside are the other nestable spar segments. This discussion example is facing two fore spars and two aft spars. The meta spars could be made up with exterior couplers or with sets of Joe Cups. The exterior couplers could produce a meta spar of 16 feet, or with Joe Cups about 15 feet as the Joe Cup scheme has spar segment overlap to assemble the meta spars. Here is a fresh opportunity in this development: a left-wing fore spar and a left-wing aft spar would consist of spar segments as follows: fore spar: ACEG; and aft spar: BDFH.

I will now let ChatGPT organize and comment over my above prose:

Development Note: Efficient Spar Packing for Tiny Packed Hang Gliders (TPHG)

This note focuses on a specific type of Tiny Packed Hang Glider (TPHG) with a design geared towards achieving ultra-compact packing for urban transport to and from flying sites. The particular design under discussion features two spar-segment sets: one for the left wing and one for the right wing, with each set consisting of eight spar segments. The emphasis here is on the spar segments, which are designed to be "nestable" during packing, allowing for the entire spar-segment set to be condensed into a minimal footprint.

Design Overview

Spar Segments and Nesting:
Each spar-segment set contains eight segments (denoted as A, B, C, D, E, F, G, H) that can be nested into each other. This results in two compact packs, one for each wing, when fully assembled. For simplicity, each spar segment is assumed to have a constant outer diameter (OD) and inner diameter (ID). Advanced technologies could explore tapered or double-tapered designs for individual spar segments, but a more economical approach keeps the OD and ID constant across each segment.

In a fully nested configuration, the spar segments in one set might be denoted as follows:

• Fore Spars: Segments A, C, E, G (for both left-wing and right-wing fore spars)
• Aft Spars: Segments B, D, F, H (for both left-wing and right-wing aft spars)

Thus, in packed form, you would see two external tubes ("O" representing the largest OD tube) for each wing spar-segment set, with smaller segments nested inside.

Assembly Methods

The spars can be assembled into a full-length configuration (meta spars) using two main methods:

1. Exterior Couplers: This method could yield a meta spar length of about 16 feet, with each spar segment connected via couplers that fit over the exterior of the tubes.
   
2. Joe Cups: An alternative assembly method involves using Joe Cups, which allows for a slightly shorter meta spar of about 15 feet due to segment overlap. The Joe Cup scheme involves an overlapping connection between segments, offering a potential trade-off between length and structural integrity.

Opportunity for Optimized Packing

A novel packing arrangement can be achieved by assigning specific segments to the fore and aft spars. For instance:

• Left-Wing Fore Spar: Segments A, C, E, G
• Left-Wing Aft Spar: Segments B, D, F, H
• Right-Wing Fore Spar: Segments A, C, E, G
• Right-Wing Aft Spar: Segments B, D, F, H

This approach not only allows for efficient use of space but also facilitates the assembly process, as each spar can be quickly identified and connected during setup.

ChatGPT tool liked to put commas instead of using my ABCDEFGH and ABCDEFGH format.

[JoeF]

Development note regarding a possible alternative way to have compression ribs:
Perhaps, instead of pushing the fore and aft spars away from each other with the compression rib by fitting special pressure-spreading feet at the two ends of the compression rib, consider this other scheme: tolerate a hole in the sock at LE and hole at TE of sail sock and tolerate longer end tubes of the compression rib (made of three tubes: central and two outer). Have the compression rib stick out through the holes; then from the projections kite back a diaper that holds the spars; have the diaper be about 3 inches in length to spread the pressure of the compression rib's pull on the spars as the action tautens the sail sock. This might add some LE drag and thus might not be chosen. As for the TE influence, the kited diaper might even be explored for an opportunity of increasing sail area or flow control. Or hybrid: see triangle push method and use that for LE influencer on spar spreading while using this other kited means at the TE scene. Experimental grounds ....

I let Chat have a go over my rough prose:

Alternative Compression Rib Scheme:

1. Design Concept:
   
   1. Compression Rib Structure: Use a compression rib with three tubes (central and two outer). Allow the rib to protrude through holes in the leading edge (LE) and trailing edge (TE) of the sail sock.
   2. Diaper Attachment: Attach a kite-shaped "diaper" to the protruding ends of the compression rib. This diaper would be about 3 inches long and designed to distribute the pressure exerted by the compression rib on the spars.
2. Benefits:
   
   1. Pressure Distribution: The diaper could effectively spread the compression rib's force across a broader area of the spars, potentially reducing localized stress and improving structural integrity.
   2. Sail Area or Flow Control: The kited diaper might offer opportunities to increase sail area or enhance airflow control, depending on its design and placement.
3. Potential Drawbacks:
   
   1. Increased Drag: The diaper might introduce additional drag at the LE and TE, which could impact overall aerodynamic performance. The extent of this effect would need to be assessed through testing.
   2. Complexity: This approach adds complexity to the sail design with additional components and attachment methods, which might affect the simplicity and ease of assembly or disassembly.
4. Hybrid Approach:
   
   1. Triangle Push Method: You might consider using the triangle push method for LE compression while employing the kited diaper for TE pressure distribution. This hybrid approach could optimize both compression and aerodynamic performance, though it would require careful integration.
5. Experimental Grounds:
   
   1. Prototype Testing: Implementing this scheme would require building prototypes and conducting tests to evaluate its performance, particularly focusing on the impact on drag and the effectiveness of pressure distribution.
   2. Sail Performance Analysis: Analyze how the kited diaper affects the sail's aerodynamic properties and overall flight characteristics.

Overall, this approach could offer valuable insights and potentially improve the TPHG's performance and packing efficiency. Experimenting with different configurations and gathering data will be crucial to determining its viability and effectiveness.

The kited diaper might be fabric or a rigid item. Maybe have three looping bridle lines to the little kite arrangement; registration of the holes for the lines to reach the diaper body might spoil this whole idea; maybe the push and push compression rib will win out, as the sail sock fitting without perfect registration might be a bigger asset to maintain; it might be too onerous to register the position of holes in the sock. Such registration and drag might put this post's main idea in the don't-do pile.

[Semper Fidelis]

With you, we still seek historical notes on the 5 ft 1 in production deal that you have mentioned.

Ranger HG in Switzerland

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Just to start

[Semper Fidelis]

Ranger HG data in German

Ranger HG data in German.jpg (95.35 KiB) Viewed 253 times

More to come

[Semper Fidelis]

Congratulations on the tube-milling progress for tube-joining for your TPHG 4.6 project!

Thank you Sir

I've no new guess on the shadow-part puzzlement yet.

Please try again

[JoeF]

This is longer than target, but has some lessons:
1.7 m or about 67 inches or about 5 ft., 7 in.
http://www.laboratoridenvol.com/projects/sps2008/index.en.html

SPS2008
"Short Pack Standard Hang Glider"
A light hang glider that folds at 1.7 m to carry inside the car, train, plane, or the cable car ...
(Click on the thumbnails and download the hight resolution PDF file)

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Today I took four L.A. City buses with a test load for a 5 ft. pack; the pack was two aluminum-framed umbrellas found in a dumpster just after my annual physical exam in Pasadena, CA.

TPHGtestBusRidesAug21of2024.jpg.jpg (30.75 KiB) Viewed 228 times

[Bob Kuczewski]

Today I took four L.A. City buses with a test load for a 5 ft. pack

Try it again with a 5 foot 1 inch pack.      

[JoeF]

Yes!. Well, after Bob's good suggestion, I measured carefully the actual pack that I carried. The pack was with two tubes sticking out; the pack was not tidy, but bulbous, unlike future neat packs. The measure: 5 ft, 2 inches. Real future packs of 5 ft or 4 ft will be neater. I carried the pack showing confidence. No talk from the drivers. Final packs will be even easier to handle. In the walking segments of the trip, I missed having three or four wheels .

Six different walk modes were used:
travois rear,
push on sphere apex,
two-handed-on-shoulder,
cradle in front hold,
hang over shoulder with one hand, and
two-arm curl hold on back at hip level.

On the bus, some varied handlings:
I'm sitting; pack standing between knees.
I'm standing; pack at chest; I press against a pole.
I'm sitting; pack slanted using seat next to me (seat not needed by others)