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Non-explosive Kite Winder

Prevent broken fingers
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I was flying my kite today at the coast. After hanging on for dear life for about an hour, it was time to reel the kite in. I had about 40-50 pounds of pull and as I was winding onto my yo-yo winder <link>, there was a massive explosion and an incredible ( @#%! ) pain in my finger.

What happened? The string was being wound (stretched) and, when enough line had been wound around the spool, it simply blew apart. I have had yo-yo winders distort in the past, but the wind was very strong today and the load was too much and it simply exploded as each wrap of the line caused more and more pressure to build up. I now have a broken 3rd finger on my left hand.

I was thinking that a yo-yo winder could be made with overlapping plates. A sort of armadillo effect, if you will, around the circumference. Before winding the string back onto the winder, it would be expanded an inch or so. As the string was wound onto the winder and the load increased, a small lever could be activated which would cause the winder to decrease in circumference by that 1 inch. This would take much of the load off of the winder and (hopefully) would cause no more broken fingers.

Klaatu, May 25 2004

Yo-Yo Winder http://www.kitesrus...=K/PROD/SLSTA/98515
[Klaatu, Oct 05 2004, last modified Jul 24 2006]

[link]






       back to typing with one finger again? poor you!
po, May 26 2004
  

       Good idea K. perhaps the slack allowed under the wound portion could be varied so as not to give too much collapse space. I'm visualizing a tighter outter wind and a munged up inner wind. like my bobbins on the sewing machine, if the inner wrap is too loose, the outter gets imbedded and twisted and won't flow out easily.   

       and then there are those who like anything that explodes.
dentworth, May 26 2004
  

       switch to the more manly 2 line or even 4 line kites failing that switch to seriously high rated kite strings i have some 500lb breaking strain stuff.
engineer1, May 26 2004
  

       I think you should be able to sue the manufacturer. (There's a good argument to be made that the string should break before the winder explodes.)
DrCurry, May 26 2004
  

       How long DID it take you to type that idea there, Klaatu?
Letsbuildafort, May 26 2004
  

       I'm not a kite string winder engineer, I'm not even a kite flyer, but would it not suffice to make the core of the winder stronger?
Gromit, May 26 2004
  

       As a young boy, I introduced the kids on my block to the concept of kite-fighting. I'd read a story somewhere on kite-fighting in India.   

       I then installed razorblades on my kite-tips.....ah, those were fun times. Champion for a day.....
normzone, May 26 2004
  

       [po] yes, I have been reduced to 50% of my prior typing speed.   

       [tabs] after the winder exploded, I tied the line to a log on the beach and used my jacket to walk the kite down. I had over 500 feet of line out, so walking it down wasn't an option until I had enough line in to clear the 38,000 volt lines.   

       [dentworth] valid point I hadn't though of. How about a sleeve of plastic which would be laid down after pressure was reduced? That way, the later windings would not burrow into the looser, earlier windings.   

       [engineer1] I don't know what the stretch factor is on 500 pound test line. Even if it had less stretch, it would still exert the same amount of force on the winder.   

       [b_p] would a foam tape change the amount of compressive force on the winder? It seems that the pressure would remain the same, although I can see some "give" with your suggestion. My next winder will be the testbed for your suggestion (after my broken finger heals)   

       [DrC] I come from a long line of folks that say "if you kill yourself doing something you love, don't blame the guy who built it." No lawsuits from me.   

       [lbaf] a lonnnnnnnng time. Almost as long as it is taking to type this anno.   

       [gromit] I was thinking afterwards, on the drive home from the coast, that there must be a way to strengthen the winder. I thought of making it solid, but that defeats the ability to place your hands on the inside to wind. The only other thought I came up with was a spoked winder. The issue of gettings your hand inside to wind still comes into play. I thought of a solid core with opposing handles that could be used to wind the string, but with no supporting axle, it would wobble like crazy when winding.   

       We had no camera. I forgot to charge my digital camera so no photos and the line was such a mess that I tossed it in the trash. Essentially, it blew inwards and to the side. the rim was largely intact, but had come apart from the rim.   

       [normzone] make flight, not fight.
Klaatu, May 26 2004
  

       This all comes down to poor engineering or manufacturing. The science dealing with strength of materials is well known and the appropriate cross section of the winder is easy to calculate if you know what you're doing. You can get the ring strong enough well before you approach having to make the thing solid.
Worldgineer, May 26 2004
  

       I would think that the right approach would be to have the cord wind around a shaft a few times before going onto the spool; the shaft would thus supply most of the tension for pulling in the kite; the spool could be left a little bit to avoid an overly-loose wind, but would not have the huge force pushing on it.
supercat, May 26 2004
  

       [Zanzibar] if you build one, be sure to get a signed waiver before you sell one to [DrCurry]. I would assume it would be 12 volt powered for use at the beach, with a solar array to maintain adequate charge.
Klaatu, May 27 2004
  

       It doesn't really surprise me that the pictured yo-yo winder is capable of implosion under stress. It's weakly designed.   

       Instead, start with the concept of a set of brass knuckles and mould that into a solid metal disc shape with a ball-bearing race around the edge; then put the string reel onto an outer-race bobbin or spool that freely rotates around that metal hand-plate with an adjustable friction control drag.   

       Wouldn't that give you the maximum structural integrity, while still giving the kite enthusiast the necessary control for fighting, evading, soaring and reeling? I'd expect the entire device to weigh nearly two pounds, but I'm not sure that's really an issue compared to the control and safety you'd recoup.
jurist, May 27 2004
  

       //The issue of gettings your hand inside to wind still comes into play. I thought of a solid core with opposing handles that could be used to wind the string, but with no supporting axle, it would wobble like crazy when winding//

As a young kite enthusiast, a number of years ago, I had such a winder. Composed of a similar construction to existing plastic winding reels, but with 2 wholes; one on each side with a 180° spacing. Into these wholes went plastic handles that were used to wind-in and wind-out the kite string. It worked well and didn't wobble too much.
silverstormer, May 27 2004
  

       How about a comfy handle with axle to solid reel. Should have a thumb operated brake and a single removable winding handle on the other side. Should be reversible for left handers. The number 1 indicates etc etc.
BillyBB, May 28 2004
  

       Hmmmm, would a sawn-off fishrod work?
silverstormer, May 28 2004
  
      
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