[JoeF]

they do not contribute anything to a good pilot's stand-up landing

OK; but what about a good pilot's perhaps-rare landing challenge where gouging basebar parts meet ground? Such happens.
One day ... ,,, I hope to design and build or have someone else do such: pop-up wheels or pop-up rollers or pop-up spoon skis or ____
that would allow full streamlining nude basebar for flight, but be an available alternative when good flare or good run out is missed.

===========================
Just saving some not-baked flashes:
== basebar streamlined complex having rotatable parts becoming two skis.
== string spokes for CO2-cannister-inflated wheels or rollers otherwise embedded in the streamlined shape of basebar.
== skid gloves
== pilot-body forward-limit line
==

[Rick Masters]

OK; but what about a good pilot's perhaps-rare landing challenge where gouging basebar parts meet ground? Such happens.

It does. But in most instances where I've damaged my glider, wheels would not have helped.
Wheels and skids are useful over a narrow speed range - what I call "tripping speed" - and a particular direction - what you call "straight."
Ground loops, collisions with brush or terrain, and losing control at touchdown - such as a wing being lifted by a thermal and the ensuing hard landing - are rarely helped by wheels or skids.
You are into advanced crash management in those situations.
Knowing how to position your body to avoid injury, and allowing the air frame to take the blow instead, are key survival techniques.
So you want to know if I would sacrifice the potential small safety advantages of wheels or skids for the decreased drag and weight and simplicity of having only the triangular control frame?
In a word, yes. Easily.
But it is each pilot's individual decision.
I am not criticising those who choose to fly with landing aids.
They're just not for me.

[JoeF]

Understood. Sales team with future product will call you later, Rick
======================================================================
First solo and sand landing:

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[JoeF]

This for suggestive design purposes only:
morph-collapsible-foam-roller
Play with iterations of streamlined basebared axial structures that may morph at pilot command to a long large-diameter roller. If the landing seems not to need the roller, then the material stays in its streamlined format. If the pilot wants the streamlined basebared assembly to deploy to round roller format, then some trigger presto-change-o pops up the roller. Thus, not just two gouging wheels, but a long fat-diameter roller.

And video:


=================================
Paper Technical, PDF Structural Behavior of Inflatable, Reinforced, Braided, Tubular Members
Joshua Clapp
University of Maine
=====================================
Two unbaked flashes archived here:
== Side-stored flat expands to roller
== Accordion-collapse to streamlined form over basetube of TCF; inflate to expand the accordioned skin to full roller when wanted. Radial string interior spokes.
== Study all bellows
====================================
PDF technical paper: Review of Inflatable Booms for Deployable Space
Structures: Packing and Rigidization
=============================================
Bellows

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

Clip from video:

AccordionSkinnedRadialSpokesInflatableBasebarBasedDeployableRoller.JPG (48.1 KiB) Viewed 9344 times

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


============================================================
Something posted in this topic thread six years ago is repeated here:

Roller hidden streamlined; deployment has basebar as axle for long roller.
============================================================

[JoeF]

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Clip from video
The beginning of Hanggliding / Playground in the Sky Full Movie

[Rick Masters]

Putting safe-splat wheels on a paraglider.

[JoeF]

2018.09.22 Skid Tests



Clip:

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[Frank Colver]

Certainly glad I had big wheels when I landed at Point of the Mountain!

Frank

[Rick Masters]

Yeah. Big wheels don't snag on stuff.
I learned that from motorcycling.
I've never flown a hang glider with wheels.
I would consider wishing I had wheels one time when I didn't.
That was the time I landed hot on asphalt.
Double density altitude!
I'll never do that again.
When somebody comes up with big, zero-drag wheels, I'll take another look.

But I don't like my belly or butt low to the ground when I land.
It's dangerous. You can hurt yourself. Think broken neck. Broken spine.
I love conventional gliders with skids.
But you're playing with fire putting them on a hang glider, imho. Too pitch-sensitive.
I've seen too much stuff sticking a few inches out of the ground to risk that.
Bushes. Rocks. Stumps. Rebar. Roots. Wire. The Evil Hand of Doom.
I like that base tube a couple feet off the ground when I flare.
Overall, it's safer. A light hang glider and a strong, well-timed flare.
I'll stick with being protected by the airframe if I screw up.
Not screwing up and flaring properly works well.
Birds got that figured out a long time ago.

[Frank Colver]

This photo is shortly after my launch at POTM. The size of the wheels can be seen here.

These are the same wheels from Northern Tool that Sunny Jim has been using for years. I didn't know this when I saw and ordered the wheels from their catalog.

Frank

BTW- BobK made good use of the wheels on one of his landings in my glider.

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