November 3, 2008 22:45 - Kimono Kite Has Conniptions In Gusts
It was the MBK 2-Skewer Sode actually, but Kimono rhymed
better! As mentioned somewhere in the site - perhaps the background page
on Sode kites - Sodes are also known as Kimono kites. Apparently, the
kite looks a bit like that Japanese garment when it's spread out.
Why the conniptions? Very gusty breeze with thermals everywhere.
On approaching the Wilfred Taylor Reserve, it looked OK with just a
little movement in the tree tops. However, there was much more breeze
higher up, and the wind was extremely gusty. It ranged from barely
enough to keep the Sode in the air to far too strong for it to handle!
Even with a heavier-than-ideal sail, this Sode is quite good in light
Initially, I took a couple of loops of tail plastic off the
kite, wanting to see how stable it really was. On just 10 or 20 meters
of line, the Sode wasn't doing very well in the gusts, so I shifted the
towing point forward a bit and tried again. Eventually quite a bit of
line was out, but the kite kept ending up on the ground, knocked out of
the sky by strong wind. Time to put those tail loops back on! The result
was better flying, but it still wasn't coping in the strongest gusts.
Around about this time, one of the spar caps kept losing its
grip on the sail. Amazingly, the flapping corner of loose sail didn't
have a major effect on the kite. I just stuck the tape back on a few
times, and then realized it was a design flaw that would have to be
fixed! Unlike other designs in the series, the spar cap tapes on the
upper spars of the Sode need to secure the spar in 2 separate
directions, not just 1.
The fix is simple. Pieces of clear sticky tape laid down at
90 degrees to the electrical tape spar caps. I've just made a note to
update the construction page for this kite. The problem is more likely
to occur in fresh wind, which is why it hasn't happened to me until
Wanting to get a reasonable flight out of the kite despite
the challenging conditions, I shifted the towing point forward yet
again. Most of the time this had the desired effect - less pressure on
the kite and therefore less tendency to loop and dive. Unfortunately, it
also encouraged a nasty little habit this kite has when the wind speed
If the Sode ever gets its nose lower than its tail, it starts
to glide forward into the wind. The weight or maybe the drag of the
slack line then tends to keep the nose down, and it glides towards you
faster than you can reel in the line, with sail rippling like a flag! At
other times, it would simply loop around and then dive slowly to the
ground vertically with not much line tension and that rippling sail
So, not the greatest outing with the Sode kite today. It
flies beautifully in light winds, even with some gusts. Today's weather
was just too over-the-top. All the 2-skewer kites except perhaps the
Barn Door would have had problems staying in the air.
November 10, 2008 02:18 - New Dopero Kite Buzzed By White Cockatoos
Winds were light so we headed down to the reserve near the
school. As usual for a new kite, I put the new Dopero on a 50 meter line
and flew around down low for a while. This gave May, my wife, a chance
to take a few 'launch' photos - one of which usually ends up down at the
bottom of the How To... page for the kite.
Unfortunately this time, the kite blew over in a gust and a
bridle line caught one of the tether lines and pulled it out. No more
flying? Well, I had to give the kite a bit more line and see what would
happen. In theory it was out of balance with unequal sail area on each
side now - but it flew OK! It seems the Dopero is fairly tolerant of
this, maybe because of that big flat central section.
It soon became clear that there were thermals popping
everywhere. Big wind shifts, insects caught up in rising air far from
the ground, a few soaring birds doing circles in the distance. In fact,
there were so many large insects that it was like listening to a distant
swarm of bees! Occasional rather fresh gusts came through at ground
level, while the lulls in between were almost calm. Regarding those
insects, a number of them seemed to be swarming around the trailing edge
of the Dopero. I've never seen that before! Small birds would flit
around the kite from time to time, hunting the insects.
Before long, a bit of a treat occurred. A flock of 16 or so
white cockatoos came by. These birds can make an incredible racket in
large groups, but this small squadron kept silent for some reason. They
were, however, quite interested in the Dopero below them, as it rose,
fell and swirled around in active air. The birds circled a few times,
keeping their distance, before doing a final pass down lower. I watched
them come between the kite and where I was standing.
For just a few moments, every bird in the group suddenly
stopped flapping, before they resumed and disappeared to the south. This
sparked a thought in my head - did they fly through a patch of rising
air, and instinctively take advantage of it? Immediately, I moved
quickly in a cross wind direction, trying to position the kite in the
same spot that the birds had just flown through. Sure enough, the flying
line tightened up and I managed to soar the kite up another 10 or 15
meters! A fluke? It didn't seem like it at the time.
With the lulls so calm, I had to pull the kite down to almost
ground level several times, before climbing it away again each time.
The best fun though was seeing this new kite accelerate directly
overhead with all 50 meters of line let out! This happened more than
once. The pale orange Dopero would even over-fly, going slightly upwind
of me, before before doing a tight 360 or 2 and settling back to a lower
line angle downwind. The line was sometimes tight, sometimes bowing out
in several directions in the warm gusty rising air.
Strong sinking air was evident too, with the kite sometimes
pulling hard but not getting above 45 degrees A strange thing happened
at one point. The Dopero began to sink quickly, tail-first, leaving a
large upwards bow in the flying line! The kite was sinking quicker than
the line could keep up. Quite bizarre, and I've never seen that before
Not long after this I handed the winder over to May while I
took Aren for a while. He's our little 2 year old. May started winding
in slowly, before the kite eventually came down, gently touching down
tail-first. That's when I got a bit of a shock. The upper sail tips had
bent to about a 40 degree dihedral angle, which is very much more than
it had when we arrived at the field! A design flaw on my part, it's now
fixed with a couple of extra reinforcers glued in place. Also, the 2nd
tether line had also pulled out. No doubt this balanced the kite up
again in terms of effective sail area, but, in addition to the extra
dihedral, this meant the kite was using much less than its designed sail
area. And yet it had no trouble going straight overhead! When all is
fixed, this is going to be an even more capable 2-skewer kite. I think
it will out-perform both the Rok and the Delta in light wind
performance. What a great way to complete the 2-Skewer series!
November 17, 2008 11:50 - Dopero Goes Up In Box Kite Weather
Not a planned strong-wind test actually, but we hadn't flown
for a while and I decided on the spur of the moment to fly the 2-Skewer
Dopero. We arrived at the reserve near the school in mid-afternoon. The
weather was sunny with a fair amount of mid-level cloud. Winds were
gusty as usual, and would have been uncomfortably strong for any of our
kites! Make that 'impossibly strong' for some of them! However, since
beefing up the upper spar joints on the Dopero, it was worth a try to
see how it coped. After a little bit of trouble with the kite blowing
around on the ground and getting its bridle in a tangle, it finally took
to the air.
The first flight, on a short line, showed up a slight
tendency for the kite to loop to the right. I decided to experiment with
adjusting just the rear bridle loop knot, to see if it would steer the
kite back the other way. After a couple of tries, the kite seemed
better, tending to go left about as often as would get forced to the
right. So far, the kite was holding up quite well to the strong wind!
With the extra vertical spar and 4 point bridle, it's much more rigid in
the air than the Roller.
I decided to keep up the abuse of this light-wind kite by
working my backwards, upwind, and letting out more line! The kite
actually got forced back to the ground a couple of times, but I just
re-launched. The Dopero is awkward to ground-launch, and it would have
been impossible in this gale anyway, so I had to walk all the way back
to it in each case. Anyway, it eventually flew around for a while with
about 40 or 50 meters of line out. Due to the wind strength it could
only manage a 45 to 50 degree line angle most of the time. Kites fly
lower if the wind is too strong, since the drag forces start to
out-weigh the lift forces over the sail.
The Dopero will never be subjected to these conditions again,
but it was interesting to find out that it will tolerate about the same
or perhaps even more wind speed than the Barn Door! While flying, I had
a good look at the tall trees downwind, and noticed that the biggest
branches were showing some movement during the worst gusts. That's
strong wind! The flying line even got a bit of a whistle up at one
point. Weather more appropriate for a box kite...
November 21, 2008 14:26 - 1-Skewer Box Kite Takes To The Air
No sooner than I had taken the last photo for the 1-Skewer
Box Kite construction page, the wind outside increased to a level that
seemed promising for a test flight! Not long later, we all set out to
the nearest reserve in Old Reynella. A fresh breeze was gusting through
from the West, with the strongest gusts moving around the largest
branches of the surrounding trees. That's what's needed!
This kite is actually the 2nd attempt at a 1-skewer box
design. The first was rather crudely made, with slightly less sail area
and also heavier sail plastic. It's in the bin now. It barely flew, even
in nearly gale-force gusts. If you are a regular here, you will
remember the blog post, since it wasn't that long ago. Now, back to the
'official' 1-Skewer Box Kite...
The first attempt was a bit disappointing, before I
discovered that the flying line had wound its way behind one of the
cross-pieces during the kite's pram-ride to the reserve. Once this was
fixed, a good gust or 2 managed to propel the little box kite up several
meters. However, stability wasn't great, and the kite wanted to travel
left all the time. Sheeesh, how do you trim a box kite right or left?
Little steering tabs on the lower cell? Meanwhile, my wife May managed
to get a few photos.
The next move was to add a little more tail. I didn't want to
add a lot more since the kite was barely able to support its own weight
as it was! This improved stability a little, but most of the time the
wind just wasn't strong enough to push the kite up above shoulder
height. Zero line angle - that's not too exciting is it...
Now I've seen a number of classic box kite designs with
single-point bridles, and some of them have the towing point set a long
way forward. As much as half-way along the upper cell, on the towing
spar. The next step with this 1-Skewer Box design is to try the towing
point at 1/4 of a skewer-length from the front. Combined with a decent
bit of strong wind, I think this little box kite will fly OK! I'd be
quite happy to see it make a 30 degree flying line angle.
That'll do, I'm off to fix the kite and update the
construction page on the website. We'll have to get some video footage
too, fairly soon while this windy weather sticks around!
November 24, 2008 16:39 - Dopero Kite Rockets Overhead - At 400 Feet!
Yup, there we were, craning our necks in the high-UV South
Australian sunshine, catching a glimpse of the 2-Skewer Dopero. The
flimsy pale-orange twin-sail design was trying to be naughty and sneak
into illegal airspace, close to 150 meters over our heads. I estimated
the line of sight to the kite to be about 85 degrees. However, with a
moderate breeze blowing a fair amount of bow into the line, perhaps the
kite was legal after all. Only just, surely.
With the end of month approaching, the pressure was on to
give the Dopero a really good flight in ideal conditions. For the sake
of the newsletter! This 2-Skewer design is the MBK kite of the month,
and so today's flying is likely to end up as the featured blog in the
Back to our arrival now, at the Wilfred Taylor Reserve. We
had noticed that the very windy weather of the last week or so had
abated somewhat, and also that the sun was out in a big way. There was
just a bit of scattered middle-level cloud here and there in the light
blue sky. Fresh gusts were coming through our back yard as we left, but
down the road a bit it was clear that it was just a big thermal day. Not
much movement in most of the tree tops that could be seen from the car.
Interesting! Rollers and Doperos love rising air.
At the reserve, the Dopero was a bit of a worry down low,
tending to loop into the ground, in both directions. Before leaving, I
had tightened the sail tether lines, in anticipation of light winds. I
wanted every square mm of sail to be working. Unfortunately, the breeze
down here was often closer to moderate rather than light. Anyway, I
shifted the towing point forward a few mm, and tried again. This time I
made sure to lay out a few more meters of line before launching the
kite. More success this time. These tail-less kites can be temperamental
down low! I think the Dopero's keels don't really kick in until it gets
a good line angle.
The Dopero seems to have a slight right-turn built into it
which causes it to loop right at a particular wind-speed. However, my
adjustment of the lower bridle loop of a few days ago seems to correct
the problem when the gusts get even stronger. Hence, although I had to
put up with the kite occasionally looping right and losing a lot of
height, it generally flew well and spent most of its time above a 60
degree line angle.
And then the magic started to happen. Caught up in a passing
thermal, the ever-shrinking Dopero scudded briskly upwind, with a smooth
moderate tension in the line. Isn't it a nice feeling seeing a kite
moving upwind against a cloudy backdrop, heading directly overhead!
After a few minutes down lower, it happened all over again. And then
later, a third time, although not quite so spectacularly. All this from a
kite that has much less area than the 2-Skewer Rokkaku. It seems that
the 2-Skewer Dopero is the most efficient kite I have ever built.
Soon it was time to head home, so May helped out by winding
on line while I pulled down the kite. It took a while, from 400 feet,
since a lot of tension would come on from time to time and I didn't want
to over-speed the kite. I promised not to abuse it in windy conditions
remember, light-wind kite that it is...