SLK Diamond Dive Bombing

[Materdaddy]

I recently bought a Prism Pica which is a diamond shaped SLK.  It likes to dive bomb.  If I am tending the kite, sometimes I can give it a lot of line quickly (how quickly depends on wind speed) and it will upright, then I can stop giving it line and it'll climb again.  Only to dive bomb again.  It always dive bombs to the left.

http://www.prismkites.com/products-sl-pica.php

I thought maybe it was something to do with wind direction, my flying, etc. however I have two kites exhibiting this problem, and two that don't.  All 3 are diamond SLKs.  I have a Dyna low wind kite that flies like a champ.  I can get it up a hundred or so feet and just stake the line and leave it alone.  The other two are kites my mom just bought my kids (6 and 7 YO).  They're both wham-o brand super cheap kites.  They have fiberglass frames and fabric sail.  They're exactly the same, yet one dive bombs like the prism, the other flies like a champ.

Is this indicative of a mis-balanced kite or something?  I've tried checking to see if something seems off-balance, or off-center but nothing it's obvious to a newb like me.

One of my kids was having a blast with their kite and the other was not happy.  I too haven't been happy with the Pica as I bought that based on a recommendation at the kite shop in SF as an easy flying kite for beginners.

[RobB]

It sounds like the wind is either too high for the kite, or the bridle isn't adjusted for heavier wind. Most single line kites can be adjusted for light or heavy wind by pitching the nose back or forward. I've had the same issues with different SLKs, usually due to the wind being too high. 

Not being familiar with the kite, I could also suggest that there may be a tensioning line that causes more or less bow across the spreaders. If the kite is too flat, it will dive out of the sky, too. If there is a bow-line, pull it tighter to bend the wingtips backwards, that will allow the kite to be more stable in the sky.

Good luck, it's not abnormal to have to tinker a bit with a kite to get it to fly right. Trial & error...

[hyzakite]

I don't think there would be a tensioning line on a diamond kite like that, but probably has a 2-point bridle that needs adjusting back a little, or a little bit of weight at the end of the kite like a tail.

But then the other kid will be happy and the one that had a blast might not be happy without a tail too.

[makatakam]

You can move the dihedral fitting up towards the top of the kite about 1/2-inch. If it's glued into position, you'll need to loosen it somehow without breaking it. Move and test fly. When it flies well enough glue it back into position. Also, when you assemble the kite and look at the front, the two spars that go into this fitting should be leaning away from you, not towards you. You can also move the connection point to the top knot. Make sure that both cross spars are the same length and go all the way into the fitting.

[Materdaddy]

Thanks for the replies.

@RobB unfortunately there are no tensioning lines on the cheapy wham-o kites, nor the prism so adjusting the bow across the spreaders isn't an option.  Too high of wind could be the case on the prism, I've flown it on days where it's blowing pretty strong.  The puzzling bit is on the same day as it dive-bombing I had the kids playing with the two (same exact) wham-o kites where one flew perfectly and the other dive-bombed just like the prism.  That leads me to believe it wasn't the wind itself, it's something with adjustments on the bad wham-o and prism.

I never realized SLK's required tuning the way it appears they do.  I figured they'd either fly (enough wind) or not (not enough wind).  I guess it makes sense if they're cheaply made, or off balance, but the prism has good build quality that makes me think it's me, not the kite.

@hyzakite you're right, no tensioning lines.  Both of the cheap wham-o kites do actually have tails so both kids will be happy.

Next time I'm flying them with the kids and those kites, I'll try to compare bridle adjustments to see if one is set with a different angle than the other.  That could explain the difference in flight of their two kites.

As for the prism I'm flying, it appears to have 2 knots about 4" apart on the 2-point bridle.  Between those two knots there is a short piece of line for attaching to the kite line which has a double-larkshead.  It looks to be 2/3 of the way toward the bottom knot of those two knots which gives the kite a more flat-to-the-wind angle.  Now that I look at it based on your comment, I'm guessing that the short attachment line is intended to be adjusted since it has the double-larkshead.  Next time I'm out with the kite in similar conditions I'll try moving that up/down to see if it flies any better.

@makatakam the kites all have a 10-15° (estimate) angle on the spreaders away from the line.  I guess in the "beginner" section  of the forum everything needs to be spelled out, but I know the shape of the kite isn't to "scoop" wind, but is shaped like a boat hull to pass the wind to the sides of the sail.  The dihedral fitting is fixed on the wham-o kites and I'm not sure I'd be able to break the glue without further damage to the $2.50 kites...

The Prism, however, has a fitting that is attached to the sail, but can slide up/down along the main spine of the kite.  It seems I can move it up/down but because it's fixed to the sail it will create a wrinkle in the sail depending on where I try to locate it.  If I slide the fitting down, there will be a crease on the sail just below the attachment point of the fitting to the sail.  If I slide it up, there will be a crease just above it.  It seems like there is a natural place for it to be.  I'll make sure it's in that natural place before the next time I fly it because I didn't pay attention to that the last few times I've had it up in the air with the dive-bombing problem.

EDIT: Accidentally double-posted trying to add this line:

My mom bought the kites for my kids because I recently reminded her about the TRLBY my parents bought me as a kid and how I was getting into kiting.  Here's a link to the cheap wham-o kites: http://www.wham-o.com/product/Superkite/72249.html

[hyzakite]

The double larkshead (Prusik knot) will slide back to change the attitude of the kite, might not fly as high but it won't go up and over into a nose dive. But just move back a little at a time. Or move the prusik all the way to the back knot right off the bat and watch how it handles, the kite may rock side to side. You'll find the sweet spot. Same thing with the Wham-O kite but maybe a little more work or a small weight on the back of the kite.

[makatakam]

Yup, move the Prusik towards the top knot in stronger wind, towards the lower in lighter wind on the Prism. You can make one to use on the Wham-O quite easily. Make a mark using a marker above and below next to the knot that forms the attachment loop. These will be your reference points like the knots on the Prism's bridle. Untie the knot and tie a loop with the Prusik onto the bridle. Voila, adjustable. Don't worry about the extra length you've given the bridle by doing this -- it's the ratio of above to below the attachment point that counts. You can make the bridle 10 feet long if you want, as long as the ratio stays the same it will fly, i.e., 1:4 is the same as 2:8. If you can't undo the knot in the bridle line just make a new one using any reasonable susbstitute.

What is making the kites turn left is more surface area on the side of the sail to the right of the vertical spine. Any which way you can move the upright very slightly to the right to increase the sail area on the left side will make it fly straight also, but is more difficult to do. You can shorten the right-side cross spar 1/16 to 1/8 of an inch, a little at a time to accomplish this, but it will decrease the amount of tension on the sail. Other option is to "increase the length" of the left spar by shortening the depth of the pocket it fits into at the tip of the sail. Sew it, glue it, or simply stuff something into it so the spar can't go as far in as it originally did. Or a combination of the two, increase one and decrease the other. Just remember that a little goes a long way, because when you change the distance on one side you are simultaneously changing it by the same amount on the other. So a change of 1/16 of an inch on one side equals an overall change of 1/8 of inch.

And if you think this is scary, just wait 'til you have to mess with the bridle on a dual- or quad-line kite. Ouch!

P.S. -- If you're not familiar with adjusting the position of a Prusik knot, Google "prusik knot in kiting" and look at a few of the listings to see how to lock and unlock the knot.

[SHBKF]

Very interesting topic.  Flying paper diamond kites as a kid we would try some of these adjustments but I suspect we moved things too much. We adjusted the bow of the kite, moved the spine, fiddled with the bridle & put way too much tail on them.  We also were flying in the suburban streets so conditions were sketchy at best.  Of course we crashed them often so they did not last too long. There was an art to carefully assembling the fragile paper sails with strategically placed cellophane tape to reinforce where the perimeter string exited the paper at each corner.  Once in awhile one of us would buy & assemble a kite that seemed to fly better than all the others.  It would be given special treatment & guarded carefully so as to not disturb the set up.  My big brother had a yellow Hi-Flier that still is magical in my memory.  Man, if I had just known some of you guys back then.....   SHBKF

 

[Materdaddy]

Thanks to @hyzakite and @makatakam I was able to get the prism to fly stable today.  I adjusted the tow toward the bottom and it continued to nose-dive consistently with each adjustment.  Eventually I was able to find a point where it flew very well.  Hopefully I can do the same with the kids' Wham-O kites next time I take them out!