This design is a one-off where I experimented with hard Tyvek as a sail material. So the sail is a touch heavy - but has no porosity at all. This Diamond has actually turned out to be very stable and efficient. A little tail weight aids stability and the carbon tube vertical spar keeps the overall weight down. The horizontal slots are a proven method of increasing the efficiency of Diamond kites in general. Flies steep!
These Carbon Diamond kite posts once appeared in the site blog page - that's the one you enter via the 'what's new!' site navigation link. Just scroll down and stop at any heading that appeals :-)
The MBK Carbon Diamond
The MBK Carbon Diamond
Carbon Diamond Hoists Camera Inland
With the wife busy at the nearby supermarket, there was a small window for some kite flying and KAP. We had both been sick pretty much all week - having survived the entire Winter unscathed up until then.
The 2 meter (8 feet) span carbon and Tyvek Diamond goes together fairly quickly and even the KAP rig setup seems to be getting easier these days. Must be the practice! A Half-Picavet suspension seems perfectly adequate since the big super-rigid Diamond has almost zero side-to-side sway in flight.
Winds today were almost too light, but the Diamond got away successfully, out to just over 60 meters (200 feet) of line. The camera was hanging just 15 meters (50 feet) from the kite this time, rather than the usual 30 meters (100 feet). No problems ensued, despite the uneven wind speed and gentle thermal gusts. Nice! We'll be getting slightly higher KAP shots from now on, while keeping the kite altitude legal.
ISO was set to auto, over the range 125 - 200. EV was left on 0.0 for the first flight. Although the camera never got much higher than 150 feet off the grass, some of the photos just caught a glimpse of the sea, several kilometers away.
Unfortunately, there was a delay of quite a few minutes in getting the rig in the air for a second photo session. Hence no usable photos were obtained, which had been set to -1.0 EV for comparison with the first lot. There were plenty of nice close-ups of grass growing though ;-) The wind had died to almost nothing in between the small thermals which lofted the occasional butterfly up towards the kite.
At least something made it into the air this week. Better than nothing!
Full-on Fences Foil KAP
It was supposed to have been a very interesting KAP (Kite Aerial Photography) session. Instead, my son and I were confronted with long and high security fencing which hadn't shown up in the Google imagery! So, instead of snapping photos of Port Adelaide from just across the water from the Western side, we ended up near Fort Glanville, down by the beach...
A rather light SSE breeze was blowing along the sand, although we stuck to the grassed area just inland from there.
The late afternoon Winter sun was struggling to peek through banks of cloud, but I still made an attempt to get the camera up.
While fiddling with the KAP rig suspension lines, the big Tyvek and Carbon Diamond gently came to rest over the dunes, on its short 15 meter (50 feet) length of flying line. This kite is usually happy to suspend the rig at this distance from the sail. However, the very marginal wind speed was making things awkward today.
An attempt to re-launch only succeeded in getting the suspension lines in a tangle! After sorting that out, and stopping the photo sequence after several had gone off, the big Diamond was launched again without the KAP gear. This was easily achieved by floating the kite out on plenty of line length, before allowing it to soar right up to 200 feet or so. Beautiful and smooth. Tail-less elegance.
Despite almost no breeze being perceptible down low, the Eddy-style Diamond with its narrow span-wise slots managed to stay at a good line angle up there for several minutes. By then though, it was time to head home, as the sun slowly set over the Gulf.
Two Big Diamonds Duel
Having just completed the 2 meter (7 feet) Carbon Diamond #3 just days ago, it was time for a test flight. No major changes from #2. Just some improvements to the spar pockets and a small shift in the positioning of the span-wise slots which let air through the sail. This airflow reduces turbulence over the upper surface which in turn makes the kite more efficient and more stable in rough air.
On the artistic side, the main factor in choosing the two sail colors was using up all my remaining containers of poster paint! Not exactly a permanent or high-quality finish, but hey, it's cheap.
The other large Diamond design was the Multi-Dowel version which has proven itself over a very respectable wind range. Today it only had to cope with a light breeze, although it periodically gusted up to around 20 kph.
Each kite was launched fairly easily, by letting out line during the gusts until the kite was hovering over the dry grass, about 20 meters (70 feet) or so out. A few firm pull-ins would then urge the kite upwards until it contacted the faster and more consistent air above tree top height. Then it was an easy matter to let further line out. To 60 meters (200 feet) for the plastic-sailed Multi-Dowel kite and a little less for the Tyvek-sailed Carbon kite.
With both kites up it was a real contrast in sounds and sight. The plastic sail fluttering quietly from time to time in bursts of extra wind speed. The Tyvek sail not making much noise - except for my experimental 'bib' tail which emitted loud crinkling sounds continuously! Looks like a giant baby's bib, but slit into several ribbons, and roughly square in overall shape.
This also happened to be the first occasion on which a kite flew with 'my-best-kite.com' stenciled on in black permanent marker. The letters were beautifully crisp from a distance, but almost too small to read from 200 feet! Ooops. Triple the size, wrap to two lines and try again, I think...
KAP Mystery Solved
Last week I came home from a KAP (Kite Aerial Photography) session down at Brighton beach, here in Adelaide, South Australia. The photos were a disaster, being totally washed out. Over-exposed, to be a little more technical. At the time I thought the problem was purely the position of the sun, relative to the direction of the camera...
Well guess what. Down at the same beach today, the photos had the same problem - and this time it definitely wasn't the sun. Camera damage seemed a small possibility since the rig had hit the sand at some speed last time, during a white-knuckle experience with the kite in rough air! Which turned out OK, but that's another story.
Anyway, once back home today, I did a little investigating with the camera, taking some test pictures from the back yard. It was a great relief to find the explanation for the bad images...
It seems that setting a fixed ISO is not a good idea for this camera in very bright lighting conditions. It can cause the camera to run out of adjustment room for other parameters, like shutter speed or aperture. When the camera was allowed to set ISO automatically, the exposure problem disappeared. Whew!
The Tyvek-sailed Carbon Diamond performed wonderfully today. It was, for the first time, hoisting the KAP rig into the air. Never has the rig been so steady for so long. Sway was almost non-existent. But whenever I handled the line the camera twisted back and forth due to the rather steep line angle from the rig to the kite. Without enough horizontal separation, the suspension lines do not provide the maximum resistance to twisting. It might be an idea to separate the attachment points even further, on the flying line.
The 2 meter (7 feet) Diamond was struggling to lift the camera in the fairly light winds coming off the ocean. At times, people on the beach had to duck under the line from me to the camera! The camera was behaving as a sort of aerial tether point, with the kite flying at a steep line angle from there.
What Prototype Kites Are For
Probing the weaknesses of course! Just been out with the Carbon Diamond again, hoping to subject it to somewhat stronger winds than the very light treatment it got a few days ago.
After measuring the wind speed near the launch point at 4kph gusting to 8kph, I moved out further from the wind shadow and soon had the big Diamond up.
This time, I just had the bow-line toggle through the loop to prevent the bow lines flapping about. They will be removed altogether, since the kite is doing fine with no bow in the spar at all. That's at rest of course - in the air, the carbon rods seem to bend just a little and the tail-heavy design plus the Eddy-like billow in the sail near the tail are enough to keep it very stable.
This location often has a rather sharp wind gradient. Sure enough, on 30 or 40 meters (100+ feet) the kite surged strongly again and again. Perhaps there was 15 or 20 kph up there. Soaring to very un-Diamond-like line angles in the cold smooth air. Putting on a few kilos of line tension now and again.
And then... phooomp ... ooops ... the vertical spar punched through the nose pocket! Fortunately the kite stayed stable, although listing a bit to one side, while I carefully brought it in. My family were surprised to see me home so soon ;-)
The camera on its little tripod had been snapping off frames, KAP-style, while I flew.
OK, now to beef up the sail around the nose area...
Towing Practice With Carbon Diamond #2
That's what it turned out to be, after high hopes of hovering a camera so it looked into the Adelaide Oval stadium. It just wasn't on for several reasons...
A clearing that looked OK on the map was way too steep and a bit small for KAP, the trees upwind were tall and the passenger jet pilots coming in to land at Adelaide airport would have had a fine view of the kite from their cockpit side window!
So, after a bit of a walk-around to look at other options, I drove back through the city to Karrangga Park on the south side of the CBD. Flags in the city center were indicating some wind, perhaps 10 - 12 kph.
Shortly after getting the big Diamond rigged and airborne, an over-enthusiastic yank on the line caused a patched-up tip pocket to fail. A carbon rod pushed through and the kite folded up. Serve me right for just using a couple of small staples to fix the original failure a few weeks ago!
So, out with the clear packing tape and soon the kite was in the air again. The sail for #3 has already been made - with a much sounder side pocket design!
By this stage the sun was close to the horizon and the breeze had died to almost nothing. After removing the KAP rig I towed up several times to between 50 and 100 feet but the breeze was no better up there either. No chance to even get an in-flight photo of the big Diamond kite. In KAP, ya win some, ya lose some.
Carbon Diamond Crash Test!
The weather was forecast to get a lot wetter over the coming days. So it was decided to make hay, ummm fly a kite, while the sun was shining. Conveniently, the wind strength was up too. The 2 meter (7ft) span Carbon Diamond No. 2 had only been flown in light winds to this point.
It was a good torture-test in very gusty wind. Down low the wind was treacherous, dropping out completely then surging to moderate strengths. Up higher, according to online weather data, it was gusting to around 30 kph. Brushing the 'fresh' range of wind speed.
The big Diamond generally did OK, only deforming the horizontal spars noticeably in the very strongest gusts. And not even the slightest hint of the fish-tailing motion that plagues my other Diamonds when they are pushed too hard.
The winder that I was using came with the 100 pound Dacron line wound on in a figure-eight fashion.
PRO: The line pulls off easily, in a rocking motion. Nice for letting out line. Also, the line stays twist-free.
CON: Loops tend to work loose and fall off the winder, causing tangles! A right royal pain in the rear end.
I'll just be looping it on in the one direction from now on.
After flying around on just under 30 meters (100 feet) of line for a while, I was distracted by the tangled mess on the winder, plus a nosey dog that had been chasing the kite whenever it got low!
Somehow, I let the kite get into a bad situation down low and it ended up spearing into the soft earth. There it was, a folded-up, flapping heap. Thankfully there was no serious damage. Just a pushed-through corner pocket - which might have actually saved the spar from snapping!
Now I'm considering pulling some bow into the horizontal rods after all, to make the kite better behaved in rough air near the ground. An insurance policy for all that expensive brittle carbon.
Carbon Diamond Prototype 2 Lifts Off
When an opportunity comes up to fly while your wife shops, it's not to be missed. An efficient use of time with just one driver in the family!
The weather sites and the fronds on the neighbor's trees pointed to the same thing... A light breeze, but with ample strength for giving the latest Carbon Diamond kite a run. Down at the school field, almost deserted except for someone trying to out-sprint their dog, the big colorful Diamond quickly took shape. Talk about easy to rig! Nothing to lash or tie, just slip a few carbon rods into place, fasten a Velcro tab and attach the line. There is also a bow-line toggle, but even that may not be necessary... getting a little ahead of myself there.
The sun was low in the sky and as often happens at that time, the breeze was slowly dying. A whole lot of short flights ensued as the big Diamond couldn't quite find the air movement to stay up. However, it was clear that the spars had adequate stiffness this time.
Every time I put plenty of tension on the line, the kite responded by accelerating upwards while hardly seeming to flex at all.
The kite was flying with a small removable weight built in, right at the tail end. The kite certainly seemed to have plenty of pendulum stability. It will be interesting to explore the whole wind range one day.
Eventually, with a lot of working the line out to about 60 meters (200 feet) or so, the big red and yellow Tyvek-sailed Diamond suddenly found faster air above 100 feet. Upwind was the school complex, on much higher ground. Briefly, the kite pulled hard and moved up to a steep line angle.
Unfortunately, the general wind speed was continuing to die off, with every passing minute.
On getting the kite back down and packing it away, I discovered that all the bow had disappeared from the horizontal spar! One of the bow-line attachment points had slid across the slippery carbon. It seems the kite is so stable that just a small amount of air pressure is enough to get enough billow in the lower section of the sail.
An interesting first flight with Carbon Diamond #2.
MBK Carbon Diamond #1
An interesting test flight session today, in very light winds. I was a bit concerned that the Tyvek sail covered 100% in poster-paint (!) might be a touch heavy, but the kite climbed willingly in the gusts. I experimented with the bridle knot positions, to get the trim right.
It was a slightly strange feeling, piloting a large painted kite made from radically different materials to those used to construct all my other home-made efforts.
But then, this Eddy-style design is being developed to eventually become a commercial kite kit. Such a kite needs to be quick to assemble, able to take plenty of rough-and-tumble in the field and above all be a great performer over a wide wind range.
Oh, by the way, the poster-painted sail is just to get an idea of what might happen if kit owners load up their sails with plenty of paint and decoration! Being a 2-meter (7 feet) span kite, enthusiastic painting should not be a major problem though.
Up and down, up and down. Letting out and pulling in the 100 pound Dacron line. All the usual super-light weather antics were employed to try and get some air-time. Almost got a photo, but the Diamond didn't want to stay up long enough, unfortunately.
Conclusion - the kite was very smooth and stable in its current rather narrow wind range. It definitely needs the next size up in carbon rods and tubes. I have had various experiences with 'floppy' kites before, and this one is more of the same. It looks like I over-estimated the wonders of carbon spars this time!