JoeF wrote:TPHG design and construction may involve the challenge of joining two tubes.
Mastering the Art of Joining Two Tubular Beams
My solution... and, if I may, I'm still waitting for more guessing about the shadow drawing
JoeF wrote:TPHG design and construction may involve the challenge of joining two tubes.
Mastering the Art of Joining Two Tubular Beams
JoeF wrote:The reference for the huge collection of hang gliders and manufacturers has been growing and has been a neat resource. But the Ranger https://www.delta-club-82.com/bible/433 ... ranger.htm page has not a packing note. Hopefully someone will dig up a photo and post it somewhere. Thanks for clarifying that the page's photo is not your friend's wing.
JoeF wrote:So, is your friend's 5 ft 1in pack a one-off?
JoeF wrote:What "tube" for your TPHG 4.6 is being milled?
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:
- 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.
- 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.
Alternative Compression Rib Scheme:
- Design Concept:
- 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.
- 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.
- Benefits:
- 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.
- 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.
- Potential Drawbacks:
- 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.
- 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.
- Hybrid Approach:
- 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.
- Experimental Grounds:
- 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.
- 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.
JoeF wrote:With you, we still seek historical notes on the 5 ft 1 in production deal that you have mentioned.
JoeF wrote:Congratulations on the tube-milling progress for tube-joining for your TPHG 4.6 project!
JoeF wrote:I've no new guess on the shadow-part puzzlement yet.
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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