February 2, 2008 22:01 - Barn Door Kite Trips Up Seagull In Mid-Air!
It was a warm sunny day, so we went down to Brighton beach and set up our beach tent on the sand. Of course we took a selection of kites as well, to cover most wind strengths except the very lightest. It wasn't hard to pick which kite to fly, after struggling with the tent in a very fresh and gusty breeze blowing towards the water. The little barn door kite, in fact the original one, was chosen since it has a good record in strong winds.
The barn door launched easily and was soon battling the breeze. Not too much line could be let out because there were plenty of people around. We had to minimize the chances of clobbering someone on the head with a bamboo and plastic missile, should the the wind get too much for the kite. The kite did get forced down a few times, but it generally coped very well, flying with line angles between 30 and 50 degrees most of the time.
There were a couple of incidents involving seagulls. Not long after the very first launch, a seagull flew past at low level and actually contacted the flying line with its feet. I felt it more than saw it, but did see the surprised bird a few meters away from the line, continuing on after clawing back some airspeed! Much later during the kite's flight, another seagull approached the line and only spotted it when less than a meter or 2 away. It threw out the air brakes, beak high and tail feathers low for just a a moment. The bird slowed down almost instantly, before it decided it was going to miss, and resumed normal flight.
Next up, after bringing the barn door kite down, was the Sode kite. With some tears in the plastic near the mid section and a hole or 2, it was looking a bit the worse for wear. However, it shot straight up after launch and actually seemed more stable than the barn door. The long tail helped! After a while the breeze picked up even more and the Sode was stretched to its limits. It's amazing a spar didn't snap, no kidding. Line angles were anywhere from ground level to 70 degrees or so.
The Sode managed to stay airborne during some gusts so heavy that clouds of dry sand started to drift across the beach. Forced into wide loops and long sideways passes, the little Sode kite started to sound distinctly like my delta stunt kite in a stiff breeze! How it held together I don't know, I was even wondering whether the 20 pound Dacron line would hold. At times the line had several kilos of tension in it, that's for sure. Bear in mind this kite is only 29 cm (12 inches) from tip to tip. I hung on while it darted in all directions, sometimes curving in an arc, other times rocketing along a straight line. It did hit the sand a few times too, but lived to fly another day.
The MBK Skewer Sode kite proved today that it has a better wind range than any other MBK kite made so far! Its first test flights were done in very light wind.
February 11, 2008 21:23 - First Tiny Dopero Kite Needs Tails
After finishing the somewhat involved construction of the MBK Skewer Dopero no. 1, we headed out to give it a test fly. Since this kite is wider than it is tall, and has a considerable gap between its main and rear sails, it doesn't end up with a lot of sail area. That plus the 4 spars required means that despite the great light wind reputation of its big brothers, this little Dopero will probably need more wind than the Sode. BBQ skewers only come in one width - thinner ones would be handy for a Dopero with a wingspan of 1 skewer!
Well, we should have brought some tails with us because... despite showing some hints of stability, it didn't take much for the Dopero to go unstable and spin tightly. In either direction, mind you, so it wasn't inaccurate construction. Not to worry, I half expected that. For a kite this small, it would take a minor miracle for it to fly tailless.
Sometime soon I will be making another Dopero, in order to write the instructions and take all the photos. The main difference will be the 2 keels under the rear sail. This time round, I'll try making them much bigger. You never know, in ideal conditions, it just might fly without tails!
February 13, 2008 09:07 - Tiny Dopero Kite Flies High With White Trash
Curious about that headline? :-) Read on for the full story!
It looked a bit windy outside, but I was dying to get the Dopero in the air again. This time, it had 2 short tails of freezer bag plastic, trailing from the lower end of each vertical spar.
Down at the Old Reynella Reserve... With the pram parked in the shade of a bush, I tried launching the kite into the light-to-moderate gusts from the south-east that were coming through. The kite was reluctant to climb, despite a nice amount of pull in the line, so I moved the towing point forward a centimeter or so. This resulted in higher climbs, but stability was still a problem. Also, there was a tendency to suddenly nose down into a dive then roll on its back, before recovering again. Some of this was just a result of the rough air flowing from the trees and bushes upwind.
By this stage, it was clear the little Dopero would not be a very good light wind kite after all. Too much bamboo and too little sail area! Plus, I'm pretty sure the black garbage bag plastic is heavier than freezer bag plastic. However, it sure looked good with its jet black sails standing right out against the pale blue sky.
To fix the stability, I added one extra short loop of clear plastic to the tails. Now the tails were joined together, forming a single loop from spar to spar. This little trick results in a more efficient tail, without adding much weight. Sure enough, the Dopero promptly soared straight up and I was able to let out plenty of line. Soon it was happily flying around at 2 or 3 times tree height, at 50 to 60 degree line angles, and behaving itself nicely.
Aren had a good time holding the flying line too, while I anchored the reel to the pram handle. He yanked the line from time to time, sending long ripples along it, halfway to the kite far above.
Although the air was smoother up there, thermals would come through from time to time and shift the kite around. Left, right and up to even higher line angles, with the line pulled nearly straight. Small white bits of rubbish floated by above, at perhaps 500 feet or higher, confirming that some rather healthy thermals were in the area! Hence the headline to this post. ;-)
A few quite strong gusts came through, but the little Dopero coped well. It shared the strain amongst its 4 bridle lines and held enough tension at times to make the Dacron line vibrate! At other times, the line would pulse with small ripples, feeling much like a fish biting at the other end.
After nearly losing the kite in some trees way off to the left, it became clear that something had changed with the kite. It continued to hang left a lot, with the flying line bowed out to the right, and ended up on the ground a few times. Perhaps a bridle knot had slipped a bit.
Eventually I pulled the kite down and we went home. Having a good look at the bridle, it seemed that the upper knot had slipped a bit, so I shifted it back and tightened the knot. Anyway, it seems we now have a delightful little moderate-wind kite to share with all the visitors to the website!
February 18, 2008 12:25 - Tiny Dopero Kite Frolics In Light Winds And Thermals
After it's previous 2 test flights, I was pleasantly surprised at the performance of the little Dopero in light winds, down at the Old Reynella Reserve. Despite being a bit heavy for its sail area, once it gets up there the Dopero floats very nicely. However, to start with we just flew it around close to the ground to get some photos.
With a few in-flight close-ups in the camera, I let the next gust take the kite out to 45 meters of line. This kite is a pleasure to fly, with no darting around as many kites of this size do.
Occasionally, the Dopero would float upwind in rising air, reaching high line angles. If this lasted too long, it would ever so gradually nose down into a dive, before turning to one side and losing a lot of height. Recovery was easy. Just releasing all tension in the line would put the kite into a belly flop, after which it would drift back with the wind, take up line tension and start to climb again.
One of these thermal encounters resulted in the Dopero floating very high overhead, before the lift died. The line went very slack and bowed in several directions! How about that, seeing the different directions the gusts are blowing in, at different altitudes.
This little kite took a while to construct, but I reckon it was worth every minute! It's turning out to be a reliable flier with quite a good wind range for its tiny size.
Finally, with the sun getting lower, thermal activity died right down and the gusts coming through were barely strong enough to even launch the kite. Even so, I did a little walk-past the camera while May took a movie, towing the kite and letting it descend until it filled the view finder! Some of that footage is going on the up-coming construction page for the Dopero kite. Keep an eye out for it under the How To Make A Kite section of the website.
February 27, 2008 14:40 - Styrofoam Box Kite's Maiden Flight
This flight actually took place quite a few days ago. I've finally decided to blog it, after not bothering since it seemed such a short and spur-of-the-moment thing at the time.
This box kite has been sitting in the corner of our work room for some months now, waiting for a suitable gale to blow! It is constructed from the foam packaging that enclosed a new microwave oven. Eight rather thick slabs of foam were butted together, resulting in 2 box cells somewhat wider than they were high. Four bamboo skewers were then glued to the inside corners of the cells, resulting in a heavy, chunky box kite!
Since this kite was not exactly square, it made sense to bridle it so it would fly flat rather than on one corner like a traditional box kite. Sort of like a simplified Hargrave kite, if you get what I mean.
To help improve its efficiency, I rounded off all the square edges with a serrated steak knife. Also, I shaped the 2 upper flying surfaces into an airfoil shape to further help its chances of getting airborne!
So, the day came when it was very windy outside. The isobars on the weather maps must have been kissing each other. We turned up at the reserve near the school and I went out by myself, while May and Aren stayed in the comfort of the car. I had to promise I wouldn't be long!
Wonder of wonders, the thing actually rose up and flew! However, it was slightly unstable, needing a more forward towing point. As a result, it looped around a few times, hitting the grass hard once or twice. A small chunk of foam flew off, but it kept flying.
At one point, a very interesting thing happened. The bridle got caught up on a corner of foam, resulting in the kite flying level on the wrong sails! The narrow ones, instead of the wider ones. However, this meant the wider sails were now acting as vertical fins and the kite was actually stable! There it sat, steady as a rock about 5 meters up, while the wind whistled around my ears. What about the airfoil section I carved, which was now sitting sideways in the air? It didn't seem to have much effect. Perhaps it made the kite sit just a bit to one side, but it wasn't obvious.
Around this time I noticed that one bamboo spar had snapped cleanly in 2 spots, right next to the foam. The kite had been flying on just 3 spars, with the wide butt joints giving it all the rigidity it needed!
For some reason, I persisted with trying to fly the kite with the bridle in its original state, thinking that I might try and move the towing point forward when we got home. However, this proved awkward so the kite is still sitting here in the room with me. For days I've had intentions of repairing it with a new spar. And of course, we'll switch that bridle around so it always flies on the narrow sides! It might prove to be a beautiful little Category 4 Storm kite... Just kidding, we don't fly when there's any chance of lightning!