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Cartwheels across the window?


genesant

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While doing the Super 16 team animations, I found the center point to be below the V in the trailing edge.

Take a sketch of a REV. Draw a rectangle around it, touching the outer points of the REV. Then draw a line from one corner to the opposite corner. Now, do the same with the remaining two corners. The crossing point would be the center.

http://revkites.com/forum/uploads/monthly_10_2011/post-41-131886868476_thumb.png

post-41-131886868476_thumb.png

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While doing the Super 16 team animations, I found the center point to be below the V in the trailing edge.

Take a sketch of a REV. Draw a rectangle around it, touching the outer points of the REV. Then draw a line from one corner to the opposite corner. Now, do the same with the remaining two corners. The crossing point would be the center.

http://revkites.com/...68476_thumb.png

But with so much of the mass and sail area concentrated near the leading edge, wouldn't it be more natural to use the center of gravity as the center of rotation? Or possibly the center of lift since it's not quite the same point? I know that a really skilled pilot can rotate the kite around any chosen center, but I'd expect it to be easier for us novices to rotate around some "natural" physical center. Of course it's possible that thinking that is the reason why I have trouble with these moves! Maybe controllability is better when NOT rotating around the natural center?

I know. I know. I'm over thinking it. It's hard to stop being an engineer and fly. :blink:

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Yes, the base line that the disk appears to be rolling upon could be any line from the ground on up. I suppose that it could even be at an angle or vertical, but I don't think I have ever seen it done that way.

BTW, this means that any point on the kite (in a properly done cartwheel) moves along a path called a cycloid . The tips of the LE move in true cycloids, while other points on the kite move in curtate cycloids.

I seem to remember that Alan Nagao 'cheated' by making a circle of 'fiberglass' (I think) tubing and hanging the Rev in it. It was then rolled across the ground... 1990 or thereabouts I guess! <grins>

Felix

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Yes, the base line that the disk appears to be rolling upon could be any line from the ground on up. I suppose that it could even be at an angle or vertical, but I don't think I have ever seen it done that way.

<snip>

I have certainly tried it on the diagonal...

We have been looking at 'rolling' the four person (or more) ball recently, well for some time actually. Now there is a challenge <grins>

Felix

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While doing the Super 16 team animations, I found the center point to be below the V in the trailing edge.

Take a sketch of a REV. Draw a rectangle around it, touching the outer points of the REV. Then draw a line from one corner to the opposite corner. Now, do the same with the remaining two corners. The crossing point would be the center.

http://revkites.com/...68476_thumb.png

That being the centre means I am closer than what I thought for all my spins!

Bart

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That being the centre means I am closer than what I thought for all my spins!

Bart

I think the true center is closer to where the center of the four lines at the point where they attach to the bridle.

I think even with my experience, I would have difficulty rotating on the center of the logo.

John

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I think the true center is closer to where the center of the four lines at the point where they attach to the bridle.

I think even with my experience, I would have difficulty rotating on the center of the logo.

John

Of course this means I've been beating myself up when I can't get that rotation on the centre of the logo! I think the rotation point for me always has been closer to where you show it. It always seems to have naturally been lower even with repeated efforts to "clean it up" and pin it on the logo.

I can ease off thinking about this one now.

Bart

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  • 4 months later...

Hmmmm g.gif

I seem to be having good luck with practicing the Cartwheel or Traveling Bicycle by modifying how I practice the precision move, Bumps. This helped me to practice Cartwheel-ing to the left for sure, where normal right-handed style practice wasn't helping.

While flying Bumps, cut the arc down to where the radius is just the length of the LE, and practice removing the stops in between "bumps". At first, It feels like a series of basic reverse launches and wingtip pivots. Once the timing is improved and the stops are removed, it winds up feeling like Bazzer described it previously in this topic - like Clockwork turns with horizontal a movement.

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Technically its a reverse half circle, but if you make the radius of the half circle the length of the LE, it becomes more of a reverse wingtip pivot in terms of how its performed. When I perform Bumps off the ground, really fast and in tight (small arcs) it becomes wingtip pivot, reverse wingtip pivot, wingtip pivot, reverse wingtip pivot, etc etc. For me anyways, this becomes a Cartwheel when i control the forward movement as the LE rotates vertical.

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I was out today, and I'm still trying to get a cartwheel down:kid_brooding: ,I think I've got the rotation part down, but I can't figure out where or what position my hands should be in, and the movement to get the kite to move across the window. Any suggestions would be great.

Michael

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My experience on hand positions is that if I hold my hands horizontal parallel (= top to right), then there is an awkward point when they need to be switched (top to left =), which causes loss of precision.

So, I am practicing the following hand positions - (| |), (/ |), (| \), and especially (/ \). Swings from one position to the other have little effect on the kite.

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My experience on hand positions is that if I hold my hands horizontal parallel (= top to right), then there is an awkward point when they need to be switched (top to left =), which causes loss of precision.

So, I am practicing the following hand positions - (| |), (/ |), (| \), and especially (/ \). Swings from one position to the other have little effect on the kite.

I would advocate horizontal handles with thumbs to the middle. Long arm pulls can then generate the rotation and small adjustments can roll the rotations. <grins>

Felix

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Nice vid Madquad. That's a mean Cartwheel you're turning there! I like the song choice. Never heard that mix before.

Hand position transition (switching) is where I was when I started chiming in on this topic...... As your hands transition, you might need to give slack to the lines (depending on flying conditions). If traveling right - from the upright position, you will be giving slack with your right hand as the Rev rotates the LE vertical, and from the inverted position, you will be giving slack with your left hand as the Rev LE rotates vertical.

wacko.gifblink.gifwacko.gif

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Just thinking it through makes some sense in my mind!! Hope the weather gets it right and I can try it out this weekend!! If not then, I'll try at the Rev clinic in a couple of weeks! I love the look of it and want to add it to my moves!! Gotta come sooner or later........ RIGHT??kid_cussing.gif

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Just thinking it through makes some sense in my mind!! Hope the weather gets it right and I can try it out this weekend!! If not then, I'll try at the Rev clinic in a couple of weeks! I love the look of it and want to add it to my moves!! Gotta come sooner or later........ RIGHT??kid_cussing.gif

I can feel the move in my arms, literally...

The long pull powers the rotation, the next pull the next half. The switch from front to back holds the kite in the sky. What more could one need apart from a slight adjustment to send it rolling from one side to the other or in diagonal lines/whatever?

Felix

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After my stroke, things can get a bit jumbled up in my head!! This sounds like the easiest way to do this!! No having to re-position the hands as you go!! Weather is looking good for Sunday, I'll be trying it then!! THANKS!! kid_devlish.gif

I'll look forward to hearing how you get on. The thinking bit is a bit jumbled for me as well but in a sense it is like flying the kite as two attached single line kites and making one accelerate around the other and then... <grins>

Felix

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