[JoeF]

What is a plate? Let plates have holes in them for various purposes (less mass, connecting beams, routing cables, ...)
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Development note:
Using Dyneema webbing to create permanent hinges for the left and right leading edge tubes and the keel tube offers a lightweight, strong, and practical solution for a collapsible hang glider or a collapsible subassembly of a TPHG. This design ensures quick folding and unfolding, making it ideal for compact storage and transport, such as on a city bus. The permanent hinges maintain the stability and integrity of the joint during flight, while allowing for easy portability. Permanently lash webbing segments to segments of spar or strut segments to achieve a hinge. Watch for telescopic opportunities in this matter.

Using two such hinges for the nose integrity can face small or large sweep angles.

In some challenges, be ready to use hose clamps.
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Toward the fun-puzzle nose piece presented by Florian for his TPHG 4.6 project, I guess further:
Left leading edge tube bolts to the left hole; the right leading edge tube bolts to the right hole; the special part fits in mid grooves of the two leading edge tubes and the keel. The apparent open hole allows a fitting and snugging of a keel beam with a bolt for such. But why the open hole? This guess might be partly right or not, maybe all wrong. Or maybe the open hole hooks a knob of a nose-rib leash that folds over the flat in the shown piece.

[JoeF]

CouplerNoHoleInWallTwotypes.jpg (11.13 KiB) Viewed 713 times

Coupler for spar segments

[JoeF]

Development Notes Regarding Gap Filling of Spar Segments into Spar Couplers

Gap filling? Place a spar segment into a receiving coupler. Notice the gap between the coupler's inside diameter and the surface of the spar segment. That gap permits wobble in the joint. Various methods are used in telescopic assemblies to stop the wobble by filling the gap. While the entire gap need not be filled, filling some interior points and areas near the end of the coupler can effectively stop wobble. However, a robust filling of the gap provides the best results in preventing wobble.

In some TPHG (tiny-packed hang glider) designs, wobble may not significantly degrade conservative performance, but a snug fit is often still desired. It is important to avoid creating a disassembly challenge by making the fit too tight.

Anticipating that meta-compression will hold spar segments in couplers, shear pinning won't be needed in the spar assembly. Rigging could pull the coupler toward the keel, snugging the inner spar segment held by the coupler. Outer couplers do the same thing, pressing the stack of segments and couplers toward the keel. This approach bypasses the need for shear pinning. Nevertheless, gap filling is essential to stop wobble.

Tabbed shims? Have a supply of tabbed shims to face various gaps. Identify the tabbed shims. Keep things clean and dust-and-sand free. Test and keep an assembly-disassembly journal on a particular TPHG experiment.

Caution when experimenting will a lubricant:
Using a tabbed shim wetted with a silicon gel or similar lubricant can have both potential benefits and drawbacks for stopping wobble in a telescopic spar segment and tubular coupler assembly. Here's a detailed analysis:

Potential Benefits

Ease of Assembly and Disassembly:
Reduced Friction: Silicon gel can reduce friction, making it easier to insert and remove the spar segment from the coupler.
Protection: Lubrication can protect both the shim and the tubes from wear and abrasion during assembly and disassembly.

Improved Fit:
Even Distribution: A thin layer of silicon gel can help in evenly distributing the shim, ensuring a snug fit.
Vibration Dampening: The gel can provide a slight cushioning effect, which may help in reducing micro-movements and vibrations.

Potential Drawbacks
Compromised Stability:
Slippery Surface: Excessive lubrication can make the joint too slippery, potentially leading to instability and increased wobble.
Shim Movement: The shim might shift or slide within the coupler, compromising the tight fit and effectiveness in stopping wobble.

Dirt and Debris Attraction:
Contamination: Silicon gel can attract dirt, dust, and debris, which can accumulate over time and negatively impact the joint's performance.
Cleaning Requirement: Regular cleaning might be necessary to maintain the effectiveness of the joint.

Recommendations
Controlled Application:
Apply a minimal amount of silicon gel, just enough to facilitate smooth insertion and removal without making the joint too slippery.

Quality of Silicon Gel:
Use a high-quality silicon gel that remains effective over a wide range of temperatures and does not degrade easily.

Regular Maintenance:
Clean the joints periodically to remove any accumulated debris or contaminants.

Testing:
Conduct thorough testing to determine the optimal amount of lubrication that provides ease of assembly without compromising the snug fit and stability.

Conclusion
Wetting the tabbed shim with a silicon gel can potentially help in reducing friction and easing assembly, but it must be done carefully to avoid compromising the stability of the joint. Proper application and regular maintenance are key to ensuring that the lubrication enhances the performance of the telescopic spar segment and coupler assembly without introducing additional issues. Even if wetting of the tabbed shims is not used, keeping the spar segments and coupler receiving cavity clean will be important.

Note: Consider using hose clamps over the exterior ends of the coupler to enhance the snug hold of the spar segment. Testing will reveal the potential benefits of this additional method when facing wobble from gap.

[JoeF]

Engineering Notes on Using Caps and Plugs for Transporting TPHG Couplers and Spar Segments

When transporting and using telescopic parts such as TPHG (tiny-packed hang glider) couplers and spar segments, protecting the ends of the segments and the interior of the couplers is crucial to maintaining their performance and longevity. Here are some detailed engineering notes on this concern:

Purpose of Caps and Plugs:
Protection from Contaminants: Caps and plugs prevent dirt, dust, moisture, and other contaminants from entering the spar segments and coupler cavities, which could cause abrasion, corrosion, or mechanical interference.
Prevention of Damage: Caps and plugs protect the delicate edges and surfaces of the segments and couplers from mechanical damage during transport.

Material Selection:
Durability: Choose materials that are durable and resistant to impact, such as high-density polyethylene (HDPE), polypropylene (PP), or silicone rubber.
Temperature Resistance: Ensure the material can withstand the temperature ranges typically encountered during transport.
Chemical Resistance: Select materials that are resistant to chemicals and UV radiation to ensure long-term protection.

Design Considerations:
Fit: Ensure a snug fit that is easy to install and remove without tools, but secure enough to stay in place during transport.
Sealing: Consider designs that provide a good seal to prevent the ingress of contaminants. Rubber gaskets or O-rings can enhance the sealing capability.
Identification: Use color-coded or labeled caps and plugs to easily identify different segments and couplers, aiding in quick assembly.

Ease of Use:
Tool-Free Installation: Design caps and plugs for tool-free installation and removal to facilitate quick packing and unpacking.
Reusable: Choose materials and designs that are durable enough for repeated use, ensuring long-term cost-effectiveness.

Integration with Transport Systems:
Compatibility: Ensure caps and plugs are compatible with any transport cases or containers used for the TPHG.
Stacking and Nesting: Consider designs that allow for efficient stacking and nesting of parts during transport, optimizing space utilization.

Testing and Validation:
Field Testing: Perform field tests to ensure caps and plugs stay secure under typical transport conditions, including vibration, impact, and environmental exposure.
Inspection: Regularly inspect caps and plugs for wear and tear, replacing them as necessary to maintain protection.

Conclusion
Using caps and plugs for transporting TPHG couplers and spar segments is a practical and effective way to maintain their cleanliness and integrity. By carefully selecting materials, designing for ease of use, and validating through testing, you can ensure that your hang glider components remain in optimal condition for assembly and use.

Consider keeping a ditty bag clean for storing caps and plugs when the TPHG is assembled. Such will keep the items clean for the packing effort.

[Semper Fidelis]

Nose plates are this, am I wrong ?

Two nose plates to maintain the tubes

NOSE PLATE.png (64.24 KiB) Viewed 690 times

[Semper Fidelis]

the open hole hooks a knob of a nose-rib leash that folds over the flat in the shown piece.

As I translate it, this is one right answer, but please, try to draw something to clearly understand

The open hole

USHAWKS - Copie.jpg (20.99 KiB) Viewed 689 times

[JoeF]

Development note:

Bonding an L-stop to the top and bottom center of the coupler is a good solution. This approach provides a secure and straightforward method to attach the rigging lines without compromising the structural integrity of the coupler. Here’s a step-by-step guide to implement this idea:

Materials Needed:
Two L-shaped metal or composite brackets
Strong adhesive (e.g., epoxy resin)
High-strength lashing material (e.g., Dyneema cord or Kevlar thread)
Sandpaper or a file for surface preparation

Steps:
Prepare the Coupler and L-Brackets:
Clean the coupler and L-brackets thoroughly to remove any dirt, grease, or debris.
Use sandpaper or a file to roughen the surfaces of the coupler and the legs of the L-brackets that will be bonded. This helps the adhesive bond more effectively.

Position the L-Brackets:
Place one L-bracket at the top center of the coupler and the other at the bottom center.
Ensure that the legs of the L-brackets that will act as stops are positioned to protrude outward, providing a surface for the loops of the rigging lines to stop against.

Lash the L-Brackets:
Use the high-strength lashing material to secure the L-brackets to the coupler.
Wrap the lashing material tightly around the leg of the L-bracket and the coupler, ensuring it is firmly secured.
Make sure the lashing is evenly distributed to avoid creating stress points.

Bond the L-Brackets:
Apply the strong adhesive to the lashed area, covering both the coupler and the leg of the L-bracket.
Ensure that the adhesive is applied evenly and that it seeps into the lashing material to create a solid bond.
Allow the adhesive to cure according to the manufacturer's instructions, ensuring it reaches full strength.

Attach the Rigging Lines:
Prepare the flying rigging line and the landing rigging line, each with an end loop.
Slide the end loop of the flying rigging line over the top of the coupler, positioning it so that the loop is stopped by the top L-bracket.
Slide the end loop of the landing rigging line over the bottom of the coupler, positioning it so that the loop is stopped by the bottom L-bracket.

Considerations:
L-Bracket Material: Choose a material that is lightweight yet strong enough to handle the loads, such as aluminum or carbon fiber.
Adhesive Selection: Use a high-quality adhesive that is compatible with the materials of the coupler and L-brackets. Epoxy resin is a good choice for its strong bonding properties.
Lashing Technique: Ensure the lashing is tight and secure to provide additional mechanical strength to the bond.
Alignment: Ensure that the L-brackets are properly aligned before the adhesive cures to ensure the rigging lines are evenly stopped.

Advantages:
No Drilling: Avoids creating stress concentration points in the coupler.
Simple and Effective: Provides a straightforward method for attaching rigging lines.
Secure Attachment: The combination of lashing and bonding ensures a strong and reliable connection.

This method should provide a robust and effective way to attach the rigging lines to the coupler while minimizing the risk of structural failure.

Quadrilateral planar diagonal stays could have terminal loops and be stopped by the protruding legs of both the L items that are integrated onto the couplers.

Note: Look for interferences in mockups.

Option: T bracket instead of L bracket; the T bracket might be more secure. Let loops move up onto the feet of the T bracket. And a T might be constructed from using two Ls, bonding the two protruding legs for the vertical projection.

[JoeF]

Tfrom2LforstopsOnCouplerNoholes.jpg (10.91 KiB) Viewed 681 times

Coupler with two Ts (each made of two Ls). Coupler to hold ends of two spar segments.
Cushions are not indicated in the drawing. The green could be a bonded interior stop of various lengths depending on targets for meta spar.
No holes drilled in the coupler. Tabbed gap fillers are not indicated in the drawing. Stay lines are not indicated in the drawing. Bracket surfaces should have polished radii for edges. Lashings are not indicated in the drawing. Though the drawing shows a gap between the two Ls, making the T bracket would close the gap fully. There would not be any sharp corners of the bracket assembly.

[dhmartens]

DC comics has a new "Kite Man"

[Semper Fidelis]

I think we could use another hint.

Here is a very precise hint to remember: No disassembling part has a screw !
If you can not assemble and disassemble a HG whithout tool, this is not as HG, periode.

Have a nice weekend guys

PS : I'm sorry to realise that we are only four participants on this topic today... Do you know potential others to wake them up ?