[Bob Kuczewski]

I enjoy most of your posts, but your most recent (above) seems to be stretching Joe's 5 foot topic just a bit.

You are correct Bob.

You post a lot of very interesting (and entertaining) information, and I enjoy reading what you find. Maybe you should consider starting your own topic as ChopperGirl has. Maybe "Doug's Crazy Corner of Coolness" 

[JoeF]

Development Note: Enhanced Joe-Cup Plug Design for Anti-Wobble Performance

In this advanced version of the Joe Cup, the insertion end of the child tube can be fitted with a mushroom-shaped end plug, featuring a semi-spherical projection. The radius of this projection will match the inner diameter (ID) of the mother tube, ensuring a snug fit and providing anti-wobble support at the junction of the child and mother tubes.

Key Features of this Design:

The semi-spherical head of the plug, with a diameter equal to the mother tube's ID, will stabilize the connection between the two tubes, minimizing any wobble or unwanted movement during axial compression.
The stem of the mushroom plug for the child will fit snugly inside the end of the child; this will stabilize and protect the inserted end of the child.
A groove along the surface of the plug will keep the Joe Cup’s strapping centered, distributing forces evenly and reducing wear during use.
An additional anti-wobble gap fill will occur where the strapping first enters the mother tube, ensuring a tight fit at this critical junction. The Joe Cup collar will protect the open end of the mother tube while anchoring the strapping, further enhancing structural integrity and preventing deformation. Recall that the collar of the Joe Cup anchors the strapping and thus limits the child's insertion.

This design modification significantly improves the stability and alignment of the tube assembly, reducing wear and enhancing the overall reliability of the Joe Cup system under axial compression during flight.

ChildPlugWithGrooveUseWithJoeCupInJoinWithMotherTube001.jpg (4.61 KiB) Viewed 467 times

During disassembly of the TPHG and during tote, the child plugs and Joe cups and possibly mother-child top plugs will store separately from the TPHG framing tubes. Plugs will be made in very many sizes to accommodate different combinations of mother and child tubes.

[JoeF]

"Pack" is a great choice!

It captures both the idea of compact packing for TPHG and the camaraderie of a group of pilots. It suggests a tight-knit, efficient group, perfectly aligned with the nature of tiny packed hang gliders.

You can now refer to a group of TPHG pilots as a Pack of TPHG Pilots, which has a strong, cohesive ring to it!

=================
Give three sentences naturalizing "pack" for a group of TPHG pilots.

ChatGPT said:
ChatGPT
"A pack of TPHG pilots gathered at the launch site, each unpacking their tiny gliders with practiced ease."
"As the pack of TPHG pilots took to the sky, their compact designs allowed them to maneuver effortlessly through the thermals."
"After a long day of soaring, the pack of TPHG pilots shared stories of their flights, their gliders neatly packed away for the journey home."
These sentences help establish the term "pack" as a natural collective noun for TPHG pilots, tying it to their style of flight and equipment.

[JoeF]

Using a Wood Lathe to Make Joe Cup Plugs and Collars: Benefits and Process

A wood lathe could indeed be a highly valuable tool for creating custom plugs and collars! Here are some reasons why investing in a wood lathe for your Joe Cup system development could be advantageous:

Benefits of Using a Wood Lathe for Plugs and Collars:

1. Precision and Customization:
- A wood lathe allows you to create highly precise plugs and collars that exactly match the diameters of your mother and child tubes, ensuring tight, anti-wobble fits.
- You can easily shape the semi-spherical heads, mushroom shapes, and grooves for the straps, which might be difficult or time-consuming to do manually with COTS parts.

2. Material Versatility:
- While traditionally used for wood, a wood lathe can also work with other materials like plastic, nylon, or even soft metals (like aluminum) when fitted with appropriate cutting tools.
- This opens up options to make durable, lightweight plugs and collars using a variety of materials.

3. Efficient Prototyping:
- Once you're familiar with the lathe, making new designs or tweaking existing ones becomes fast and efficient.
- Perfect for testing new versions of plugs or collars, adjusting dimensions, or adding custom features (e.g., deeper grooves, different stem sizes).

4. Cost-Effective:
- A wood lathe allows you to produce parts in-house, reducing reliance on pre-fabricated or customized COTS parts, which can be expensive or require long lead times.
- Especially for experimental work, this can save both time and money.

5. Versatility for Other Projects:
- Beyond Joe Cup plugs and collars, you can use the lathe for creating other custom components related to your hang glider projects or even general DIY work.

Steps for Creating Your Own Plugs and Collars:

1. Select the Material:
- Use hardwood, plastic, or composite materials like nylon or Delrin (which are commonly lathed). These materials will be durable under axial compression and are easily machinable.

2. Turn the Plug Shape:
- Use the lathe to turn the mushroom-shaped plug, ensuring the semi-spherical head has a diameter matching the mother tube’s inner diameter (ID).
- Ensure the stem of the plug fits snugly inside the child tube.

3. Add Grooves:
- After shaping the plug, use a lathe tool or hand tools to carve out the groove along the semi-spherical head that will seat the Joe Cup's strapping securely in place.

4. Fabricate Collars:
- Use the lathe to turn perfectly round collars that snugly fit around the end of the mother tube, providing a strong, wobble-free fit.
- You can also use the lathe to create collars with more intricate designs, such as those that need to accommodate additional fastenings or reinforce specific areas.

5. Finishing:
- After turning, sand and finish the pieces to remove any rough edges, ensuring smooth, precise connections that minimize wear during assembly and use.

Tools to Consider with a Wood Lathe:
- Lathe Chisels: A set of high-quality chisels is essential for precision shaping.
- Drill Chuck Attachment: For drilling accurate holes or creating perfect cylindrical recesses.
- Faceplates or Collet Chucks: For securing larger or irregularly shaped workpieces, like when you’re making collars.

Using a lathe will give you complete control over the design process, from materials to shape, and will allow you to fine-tune your Joe Cup system for optimal performance!

[JoeF]

Question: COTS Parts That Might Be Modified to Make Joe Cup Child Plugs?

Response:

There are several off-the-shelf (COTS) parts that could potentially be modified to create the child plugs for your Joe Cup system. Here are a few ideas:

1. Furniture End Caps and Inserts:
- These are commonly used to cap the ends of metal or plastic tubing (e.g., for table or chair legs). They are often made of durable plastic or rubber and are available in many sizes, making them a good candidate for modification.
- You could sand or machine these caps to form the semi-spherical head and add grooves for the Joe Cup strapping.

2. PVC Pipe Caps and Plugs:
- PVC fittings, such as pipe caps or plugs, come in a variety of sizes and are inexpensive. They can easily be modified with a lathe or hand tools to match the required diameters and shapes.
- The material is lightweight and durable, and the smooth surface can make for easy insertion and removal in tube systems.

3. Nylon Bushings or Plastic Inserts:
- Nylon bushings, often used in machinery for reducing friction or wear, could be repurposed as child plugs. Their cylindrical shape is ideal for modifying into mushroom plugs, and nylon is a strong material that can handle stress and compression well.

4. Soft Rubber or Silicone Caps:
- Caps designed for protecting threads or tube ends during transport or construction could be adapted. Silicone or rubber caps can be lathed to shape the rounded plug and provide a snug fit in the child tube, with the added advantage of flexibility.

5. Plastic or Wooden Drawer Knobs:
- Drawer knobs with a mushroom-shaped design could also be a useful starting point. These are readily available, and some already have the shape you’re looking for. You would only need to adjust the diameter and potentially add the groove for the strapping.

6. Bearing End Caps:
- End caps for bearings or other mechanical systems might already have the precise tolerances and durability you need. You can machine these to add the groove for the strapping, if needed.

Each of these parts could serve as a basis for the child plug and could save you significant time in prototyping. Combining them with some light modification (using a lathe or hand tools) might meet your specific requirements.
===================================
Consider: tube cap bonded to a half ball. Groove the half ball.
Consider: Bond half ball to a plug segment. Groove the half ball.
Consider: Mill a half ball to have the child end fit in the milled cavity.
Consider: Drill or mill a hollow in a half ball to make a cop for the child; the diameter of the half ball fits the mother's ID.

Considerations for Joe Cup Child Plug Design

Here are some design considerations for enhancing the child plug in the Joe Cup system:

1. Tube Cap Bonded to a Half Ball:
- This design involves bonding a tube cap to a semi-spherical half ball. The integration of the half ball can help stabilize the connection with the mother tube. Grooving the surface of the half ball can assist in centering the strapping during axial compression, thereby reducing wear.

2. Half Ball Bonded to a Plug Segment:
- In this approach, a half ball is bonded to a plug segment, creating a seamless transition. Grooving the half ball will provide additional functionality for strapping and help distribute forces evenly, enhancing the structural integrity of the assembly.

3. Milling a Half Ball with a Cavity:
- By milling a half ball to have a cavity that fits the child tube snugly, this design ensures a secure connection. The tailored cavity can provide additional anti-wobble performance at the joint of the child and mother tubes, while also protecting the child's tube end.

4. Drilling or Milling a Hollow in a Half Ball:
- Creating a hollow in a half ball to make a cap for the child tube is another potential solution. The diameter of the half ball can be designed to fit the inner diameter (ID) of the mother tube, ensuring a snug fit that minimizes wobble. This design can further enhance the connection's stability during axial compression.

Each of these options presents unique advantages and may contribute to improved performance and durability of the Joe Cup system under flight conditions.

==================================
Potential for 3D Printing Child Plugs and Collars

I do not currently have access to a 3D printer, but I believe that the designs for the child plug and collars would be excellent candidates for 3D printing. This method could provide precise fits and intricate geometries, allowing for custom designs tailored to the specific dimensions of the mother and child tubes.

Using 3D printing technology for these components could lead to enhanced performance and ease of assembly, as well as the ability to quickly iterate on designs as needed. I would encourage those with access to 3D printers to explore this option for creating effective and reliable components for the Joe Cup system.
-----------------------
====================
Could we mold the parts by shredding Dyneema fibers and mixing them with epoxy or silicone, then pressing this mixture into a mold to create the child anti-wobble strap-holding plug cap?

[dhmartens]

I have found a trending company that is most likely to be able to produce a 5 foot packed airframe.
https://www.sypaq.com.au/



I started my electric bike company Ebike4 14 years ago and it was way ahead of its time, I took a walk today and saw 4 electric bikes and 3 electric scooters driven by people who were only 4 years old 14 years ago.

I am just ahead of my time, I have gotten used to it. My cousin moved to Van Nuys in 1990 to sell solar panel for homes but failed because he was ahead of his time too.


My 4 foot telescopic hang glider breaks down to 8 inches and fits in my pocket.

Rick Masters explains why we are even looking at the 5 foot movement.
https://ushga.aero/masters/pdmc/#:~:tex ... 20collapse.

Many paragliders also have wised up and are looking for a solution.
https://www.paraglidingforum.com/viewtopic.php?p=p14765
I am sorry if I am results oriented.

[JoeF]

Development Note Regarding Child Plug's Groove:
Consider turning a full ball while carving out a groove along its surface. Once the groove is made, cut the ball in half so that the groove intersects the cut at a 90-degree angle.

Then, bond each half of the ball to a pedestal that fits the inner diameter (ID) of the child tube. The ball's diameter should match the inner diameter (ID) of the mother tube for a precise fit.

[JoeF]

Development Note Regarding Rigging Anchor:
Take two line segments and form a loop with each segment. Optionally, interlock the two loops.

With the two loops side-by-side and stretched out linearly, tie them together into a knot, with the knot at the center of the two initial loops.

Using a jig matching the diameter of the mother tube, wrap the center region of this assembly (now showing four smaller loops or loop petals) around the jig. Continue to wrap and knot, and potentially finish by potting the wrapped portion with silicone; allow it to cure.

At assembly, the axial tight loop formed over the jig with the wrappings and knotting will fit over the child tube at the entrance area of the mother tube. This axial tight loop of the rigging anchor will butt up against the Joe-Cup collar and the Joe-Cup strap at the edge of the end of the mother tube.

This will create a rigging anchor with four smaller loop petals. Two loops can be used for planar diagonal stay lines, one loop for anchoring a kingpost crossline, and another for a queenpost crossline. The rigging anchor will pull toward the keel and be stopped by the Joe-Cup collar at the spar-segment join.

[JoeF]

Development note about child-tube plug:

Instead of a full hemisphere presentation exterior of the child's end, consider having just the strap path be circular; the whole dome is not needed. But lateral support is recommended. There can be a mass savings when going for the focused needs. Keeping the Joe-Cup strap on the path can be solved in several ways. Let's look forward for more development on this opportunity. Such fresh concerns may well simplify making various sizes of child plugs with less costs than grooving full half balls.

AI massaged the above:

Development Note Regarding Child-Tube Plug:

Instead of a full hemisphere protruding from the exterior of the child's end, consider simplifying the design by focusing only on the circular strap path. A full dome is not necessary, though lateral support is still recommended. This adjustment could lead to significant mass savings by addressing only the critical needs of the assembly.

There are multiple ways to ensure the Joe-Cup strap stays on the desired path, and this simplified approach opens the door to further development opportunities. Additionally, this refinement may reduce production costs by eliminating the need for grooving full half balls, especially when producing child plugs of various sizes.

More exploration into these design efficiencies is encouraged as this opportunity develops.

[JoeF]

I let ChatGPT massage my notes. Here is the produced response:

Title: TPHG Concept: Structural Battery Frame and PV Sail for Assisted Gliding

I've been working on the concept of incorporating structural batteries and photovoltaic (PV) sails into a Tiny Packed Hang Glider (TPHG). The aim is to have the hang glider operate primarily as a free glider but with occasional power use for safety during landing, thermal catching, or assured destination reaching.

1. Structural Battery Frame
A structural battery allows the frame of the hang glider to store electrical energy while also being a load-bearing component. The key here is to use carbon fiber-reinforced polymers infused with battery technology.

- Materials: Carbon fiber composites integrated with lithium-ion or similar battery chemistries would provide both strength and energy storage.
- Weight: The structural battery must maintain a balance between being lightweight and offering sufficient energy density.
- Capacity: Enough power for occasional use, like assisting with landing or reaching a thermal.

2. PV Sail for Energy Harvesting
The sail of the TPHG would be equipped with flexible photovoltaic cells to capture solar energy and charge the structural battery during flight.

- Materials: Thin-film solar cells like CIGS or perovskite would be lightweight and flexible, integrated into the sail fabric.
- Surface Area: The sail offers a large surface area for collecting solar energy while gliding.
- Durability: The cells need to withstand folding and packing while still being functional after long-term use.

3. Power Use for Assisted Gliding and Landing
The power from the structural batteries can be used strategically to enhance the glider’s performance in critical moments.

- Assured Landing: Small electric motors or foldable propellers could provide power for controlled landings, especially in tight areas.
- Thermal Catching: Power can be applied to reach thermals more easily or assist with altitude gain when thermals are weak.
- Extended Flight: If needed, power can ensure you reach your destination, particularly if gliding alone won’t suffice.

4. Integration with the TPHG Design
The structural battery system aligns well with the TPHG's focus on portability and compact packing.

- Modular Design: Each spar segment could house battery modules that connect when the glider is assembled.
- Power Management: A smart system would manage charging from the PV sail and the distribution of power to the motor when needed.

5. Challenges
- Energy Density vs. Weight: Finding the right balance between energy storage and keeping the glider light enough for free flight is key.
- Durability of PV Sails: The folding and unfolding process could wear down the PV cells, so durability is a major concern.
- Efficiency: PV sails might not always provide enough charge during the flight, so maximizing efficiency is important.

Summary
- The structural battery acts as both a load-bearing frame and an energy storage system.
- A PV sail with lightweight, flexible solar cells charges the battery during glides.
- Energy from the battery can be used for landing safety, thermal catching, and range extension.
- The design remains true to the compact, portable nature of the TPHG.

This approach could provide a new level of control and safety to free-flight hang gliders while staying within the lightweight and portable design goals of a TPHG.