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Author Topic: I wish this had been my idea  (Read 2716 times)
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KaoS
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« on: August 31, 2018, 04:13 AM »

http://www.youtube.com/watch?v=http://www.youtube.com/watch?v=$1#errorNo longer available

Why does the forum do that??  I post the link

Quote


, and sometime later the forum changes it.

Any clues?
« Last Edit: September 03, 2018, 05:13 PM by KaoS » Logged

Kevin Sanders

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midibot
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« Reply #1 on: September 02, 2018, 07:25 PM »

I have just been getting an error message saying "Video unavailable" on this each time I've tried (from Canada fwiw).

.
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Oldgoat
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« Reply #2 on: September 03, 2018, 08:26 AM »

Oooops,  I'm now getting that message as well.  I'm glad I had the opportunity to see it previously.  I'm also curious about this thread.  It seems to me that a couple of posts are missing.  Hmmmmm.
 Smiley
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riffclown
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« Reply #3 on: September 03, 2018, 10:09 AM »

I think I may have captured the actual link..
https://www.youtube.com/watch?v=6iSAjvA-R40
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midibot
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« Reply #4 on: September 03, 2018, 11:33 AM »

I think I may have captured the actual link..
https://www.youtube.com/watch?v=6iSAjvA-R40


Ahhh, thanks riff.

Multiple Pop Kan kites, meet Circoflexes*!

Lot going on there, neat.

*Circoflexi?

.
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oldflyer
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« Reply #5 on: September 03, 2018, 12:39 PM »

Loved that! Thanks for sharing!  Smiley
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Oldgoat
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« Reply #6 on: September 04, 2018, 08:01 AM »

Yes that link works for me as well.  I kinda wish I hadn't seen it though Roll Eyes  Let's see, two circoflexes and a whole bunch of barrels.  And of course several "tinker toys" for the barrels and  Huh  Good grief!
 Smiley
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thief
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« Reply #7 on: September 04, 2018, 09:34 AM »

sort of like a Sonja Grachen (i probably butchered her name) kite who makes wonderful kinetic spinning kites..
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Fly Market
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« Reply #8 on: September 04, 2018, 04:54 PM »

Anyone notice that some of the spinners are clockwise, some are counterclockwise? I'm assuming there's a reason for it, like balancing torque or negating the Magnus effect. Anyone understand the physics there?
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chilese
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« Reply #9 on: September 04, 2018, 06:43 PM »

The P38 Lightning has counter-rotating propellers also.

My friend Ian had specially made counter-rotating tails

made for his Sutton 125.

There are a few single engine planes that have in-line

c-r props to recover spin energy from the lead propellor.
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Oldgoat
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« Reply #10 on: September 05, 2018, 08:44 AM »

Good catch, I hadn't noticed the counter rotating feature.  Probably because watching it closely makes me dzzy Wink
It also reminds me of some of the kinetic renederings of the Grimsels I admired years ago.
 Smiley
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Roger
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« Reply #11 on: September 05, 2018, 12:20 PM »

Anyone notice that some of the spinners are clockwise, some are counterclockwise? I'm assuming there's a reason for it, like balancing torque or negating the Magnus effect. Anyone understand the physics there?

I don't think the magnus effect applies because the cylinders are fixed. It may be that if all the cylinders rotated the same way, the gyroscopic effect would cause the whole structure to precess, i.e. wobble in place. So as it is, the counter-rotations cancel the gyroscopic torques and the ring remains in one plane perpendicular to its central axis.
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Roger
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« Reply #12 on: September 05, 2018, 03:28 PM »

I don't think the magnus effect applies because the cylinders are fixed. ...


Hold on there chief. What about roto-sails? They use the Magnus effect & they are fixed.
Point taken. However, unlike the wind-powered cylinders on the Bali kite, roto-sails are engine powered and they are in motion relative to the wind. Moreover, roto-sails are closed cylinders while the kite cylinders are open at both ends to the wind on their interiors and the Magnus effect is an outer surface artifact. So while the cylinders provide lift, I think the lift comes from the usual suspects in cellular kites and not the Magnus effect.
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Fly Market
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« Reply #13 on: September 05, 2018, 04:49 PM »

Right, I've only ever seen one Magnus effect kite (built by Bill Bigge, an actual rocket scientist), and the cylinder was horizontal, parallel to the ground. Not sure the verticals would have the same effect. I think you're more accurate with the gyroscopic torque. I'm planning some spinning kites, and the spin direction wasn't really something I'd thought about much... until now.
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Roger
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« Reply #14 on: September 05, 2018, 05:23 PM »

Right, I've only ever seen one Magnus effect kite (built by Bill Bigge, an actual rocket scientist), and the cylinder was horizontal, parallel to the ground. Not sure the verticals would have the same effect. I think you're more accurate with the gyroscopic torque. I'm planning some spinning kites, and the spin direction wasn't really something I'd thought about much... until now.

Bill's setup makes sense as the direction of driving/lifting force on a rotating cylinder is at right angles to the wind and a right angle to a horizontal cylinder is more-or-less up (or down). On a vertical cylinder the force would be side wise. Worth noting too that the reactionary force of a disturbed gyroscope is at right angles to the direction of the disturbing force.

Maybe we can track down the maker of this kite and do some brain picking.

Keep us up on your spinner!  Smiley
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