It's an archive of sorts, although there are no dates and times. Kite flying is timeless, don't you agree? I trust there is plenty in here to educate, inform and often entertain!
Try the Making The MBK Paper Sled Kite PDF, if you are interested in making this paper-sailed and paper-sparred sled for yourself. Handy for working offline or from printouts.
These short flight reports 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 :-)
Paper Sled Kite
Paper Sled Under Attack
The first task was to try and trim out a tendency to loop to the left...
Another manifestation of the problem was bobbing much further to the left than to the right. Retying the bridle to slightly shorten one line fixed the problem nicely.
MBK Paper Sled
MBK Paper Sled
A curious seagull got very close to the Paper Sled today, holding station for seconds at a time just centimeters from the sail. Thankfully the bird stayed clear of the almost invisible thread flying line.
The hapless kite was under attack from the ground as well, when an equally curious dog trotted around to say hello. Not being a dog person, I ignored the greeting. And then the dog raced off, snapping the thread as it went! At least I could log 20 minutes from the flight.
After retrieving the Paper Sled from the footpath where it fell, I flew the kite as I walked along beside the Esplanade, down the concrete steps and back onto the beach. Leaving the winder secured by my carry bag on the sand, the sled continued to fly in roughly the same position as before. The embarrassed dog owner was nowhere to be seen.
It was supposed to be quite a long flight of an hour or more, but the tide put an end to that! Having nearly got wet feet I hastily pulled the kite down after only 35 minutes in the air.
A prototype of the next Paper design - the Diamond - did quite well on it's 4-point bridle. The kite had a tendency to sit to one side or the other at times. I'll be doubling the dihedral angle to try and cure it, to avoid adding more heavy tail. It's all A4 paper you know...
Paper Sled Overcome
As in, the little Paper Sled got overcome by sheer wind speed today!
It seemed like a good opportunity to get in another long flight. The breeze was pushing bushes around in the backyard, which would be no problem for the Paper Sled. However, the air was forecast to be much stronger towards the middle of the day. So I wasted no time and got out to a large field before 9:30am.
For some reason, perhaps some tangling near the bridle knot, the Sled had a tendency to loop to the left. Gaining height was a struggle since the gusts were near the top of the kite's range. Too much pointing sideways to make much headway into the sky! Several minutes went by as I let out line and found a suitable spot to anchor the thread.
To cut a long story short, I spent plenty of time walking back and forth, relaunching the kite. And mending a break in the flying line at one point.
Eventually, I tried a small ribbon of Tyvek knotted to an outer tail streamer. The Paper Sled consequently maintained enough balance to stay quite high for some time, unattended. Unfortunately, the wind speed had continued to build until the thread parted once again. This cut the flight time to just 7 minutes.
The beginnings of a small thunderstorm were gathering almost directly overhead. So it was definitely time to pack up and get out of there!
Disappointingly, today's busy outing only returned a small amount of loggable flight time. There's a club kite fly on tomorrow, so we'll try again then, at the same field.
Finally, The Right Sled
Just on impulse I searched the web for high-wind Sled kite designs...
One in particular seemed very promising, having a huge claimed wind range. Now, with everything in 40 gsm paper, my version was not going to match the claims - but would it do better than my several attempts so far?
The design was an old Allison 2-sticker. My current designs were quite similar, right down to the angled longerons. But perhaps this classic one was tuned to perfection...
After getting busy with fresh sheets of paper, scissors, tape and polyester thread, a new Sled was soon ready to fly. I had a good feeling about this. For one thing, the flying area was somewhat less than my original Sled, which would help the thread stay in one piece at the upper end of the wind range. The classic version flew tail-less, but I retained a 50 cm long curtain of 1cm ribbons to keep that weighty sail from swinging around too much.
Down at the park, the breeze was initially too light to make much progress with testing. But then, with distant rain clouds approaching, the wind whipped up. Gusts were well into the 20's in kph, moving the tree tops. And the little Sled loved it!
For quite a few minutes it was a pleasure to watch and feel the Sled surging around on more than 30 meters (100 feet) of the thinnest cheapest polyester sewing thread. It held. The design is nailed. I thought it was nailed before, but the original kite was hindered by an excessively long and heavy tail that was needed to keep it stable. Also, the problem with frequent line breakages due to too much line tension. It's all good now, although tangles and knots could still part the line in fresh wind.
Paper Sled Touch-n-Goes
Student pilots do it - touch down, apply throttle and take off again...
The Paper Sled did something similar, several times today. There was a gusty and gutsy breeze from the east, pushing through the trees at close to 20 kph and flowing over the top at 30 kph or more during gusts. The kite would sometimes contact the grass nose-down, only to rotate a bit to one side and promptly climb away again.
Once again, the polyester thread flying line was tested to its limit. The thinnest portion, which was attached to the kite's bridle, gave way a couple of times.
I ended up getting rid of the thinnest thread and tying the kite onto the somewhat stronger thread further back. It was still ordinary polyester sewing thread but at least one size up from the very thinnest available. No line breaks occurred from then on.
Funnily enough, it was the line of trees getting in the way of the breeze that often kept the kite in the air!
Time and again, the Sled would circle tightly to one side or the other, driven to instability by the air pressure. However, after losing enough height, the slower air in the wind shadow would allow a recovery. Just in time for the kite to move back up. With the worst of the gust having moved off downwind, the kite would climb to full height once again.
Occasionally, a break in cloud cover would bathe the entire field in sunlight. Moments later, the kite would take advantage as the slightly warmed air drifted upwards. As evidenced by higher than usual line angles, despite a slight drop in wind speed. A bit harder to pick with a heavy 40 gsm paper kite, but the effect was there.
Some of the touch-n-goes consisted of a brief sweep of the tail against the grass!
Finally, a much longer flight of 30 minutes was recorded. The Sled managing to recover height many times without any paper actually touching the ground. After adding a little more tail, I'm hoping the remaining hour of flight time for certification can be achieved in just one or two flights. Perhaps down at the beach in smoother winds...
Paper Sled Logs Flying Time
That 's what it was all about this morning. Edging towards the 3 hours of total flying time required for certification...
Why 3 hours? All to expose the design to several separate flights, manual handling and a range of weather. Ensuring that future builders will have a good chance of getting a reasonable amount of flying out of the kite.
The wind range being experienced at the nearest weather station was just perfect for the Sled. Down at a local reserve, the tree tops were moving about. It was going to be another gusty time with wind speeds varying all over the Gentle to Moderate range.
After a couple of short flights it was clear that flying on the longest possible line would be a good idea. Kites made from A4 paper come down in a hurry during lulls! So, I eventually reached a far corner of the grassy area which allowed a good 90 meters (300 feet) of thread to go out. This also made allowances for retrieving the kite should the thread break!
After a full 10 minutes the Sled descended to the ground - only to relaunch itself once again shortly after. Up high, strong thermals were pushing the kite hard with almost-Fresh air speeds. Also very noticeable were large changes in the wind's direction as air got sucked away to the left or right. A patch of slower-moving sinking air nearly grounded the Sled once more - but it clung on just clear of the grass before making a spectacular climb. This flight lasted for 15 minutes.
Finally, with the average wind speed seeming to drop a little, a lull brought the kite down after just 5 minutes. I didn't intervene - that's against the rules ;-)
It was time to call it quits. A useful 25 minutes of flight time had been logged.
Paper Sled Nearly Nailed
I wouldn't call it 'nailed to the sky' as such, but....
The Paper Sled is on it's 3rd prototype. After today's flying outing, it would appear the design is 90% there. 'Nearly nailed' in other words. The next 40 cm tall Paper Sled will be done in colored paper, with just a few minor tweaks to ensure that it gets through it's up-coming certification flights. I'm serious about this stuff ;-) .
The aim is to produce real sparred kites that use no spar material except ordinary copier paper and sticky tape. Today saw a wonderful proof of concept.
Pulling up at a small grassy reserve that I hadn't flown at before, the breeze looked ideal with tree-tops being ruffled. Being rather heavy for their size, these paper designs require more than a light breeze to stay up.
Initial attempts at flight were disappointing. The kite was flying stable but refusing to rise more than a meter or 2 over the grass. Thoughts followed, of having to abandon the entire idea of copier-paper kites. But then, I moved over to a more open section of the reserve, where wind blew through with less interruption from trees and houses...
Success! The dodgy-looking kite, fashioned from pieces of obviously used A4 paper, began to soar high over the grass. Now well above tree height, the small paper kite drew the polyester sewing thread almost taut. In the strongest gusts, the thread flying line stretched a little but held.
After a while, there was around 60 meters (200 feet) of thread in the air. The small Sled moved around quite a lot in the gusty Gentle to Moderate breeze. 80cm tails rustling furiously, although they remained undamaged. Perhaps 20 minutes later I brought the kite down. Wonderful!
Next in the series will be a Paper Diamond.
Paper Series Lifts Off
Perfect conditions for testing the Paper Sled today...
The Sled is the first of what is hoped to be a series of 20 or so designs. All made from paper and sticky tape and flown on ordinary polyester sewing thread. No straws, bamboo or anything like that! Strictly paper and tape.
The aim for every kite will be to fly the Gentle and Moderate wind ranges, up to 200 feet and durable enough to last for 3 hours total flying time each. Talk about a design challenge!
Today's Sled managed to fly in winds towards the high end of Gentle - approaching 20 kph. However, it's wind range was narrower than even a small kite should achieve.
I won't let on just how the paper-only spars are made just yet - but the current ones had ample strength and rather too much weight it seemed. Easily fixed by trimming down the dimensions.
The tails worked but needed more effectiveness in fresher breeze strengths - so they are getting wider.
I tried paddles on the ends of the tails to make them much more effective. However, the extra paper on the ends spun like windmills, twisting up the ribbon tails and occasionally joining them together as the kite flew! Toss that idea.
So, I'll shortly be whipping up another kite with slimmer spars and wider tails. Not too time-consuming when it only involves a few sheets of paper...
Don't forget to try the Making The MBK Paper Sled Kite PDF, if you are interested in making the Paper Sled for yourself. Handy for working offline or from printouts.