Blue parafoil – Misc postings from Nick Wallingford

Good movie from kite…

Far too long since I’ve written anything. I’ve been quite busy, mostly with baking activities that I’ll have to ‘backfill’ as I get a chance…

But yesterday, finally got a decent day to put the blue parafoil up at the Tauranga waterfront, along with the GoPro camera. I had, earlier in the day, ‘re-rigged’ the Picavet camera stabilising rig (see an earlier posting) using a heavier line – not that it needed to be stronger, but I was getting tired of untangling the finer line I had originally used.

Click on this image to see the larger version so you can spot my kite off to the right above the wharf!

What I was hoping was that I could have it in the air long enough to get recorded by a Tauranga webcam. That camera takes a picture every 10 minutes through the day – and I figured if I had the kite up, it should be visible when I get home to check that webcam. And it was – you can see the blue shape appearing to float above the wharf off to the right side of the picture!

The flight itself was not particularly long (a bit over 4 minutes of film) and somewhat limited as I only had a small roll of line, so couldn’t put it especially high into the air. Given it is central city and not a very big place to fly a kite, that’s probably a good thing.

You can see me launching the kite. I had it relatively low in the air, up until the 3 minute mark when I have let out all the line. I see there’s something of a scratch of some such on the lens, just to the left of centre – I try not to look at it…

And naturally, when I was finished, I went to have a beer at the Crown and Badger!

Camping and kites…

We took our caravan up to the Bowentown Motor Camp for two nights last weekend. Averil spent time fishing, I got to fly some kites.

Finally, a good chance to see the blue parafoil at its best. Friday’s winds were a bit erratic, but I got both the purple and the blue parafoils flying well. Never easy to take good photos of kites in the air, as once you get them up high enough, they are just specks on the photo, anyway. And given it was just a cellphone camera, the kites were generally out of focus (if you click on the image to the right, you will get a better version of it…)

Both kites had substantial amounts of tail, to counteract the gusty wind. First time I’ve flown the blue parafoil with both the long tail but also the drogue at the end of that. It looked pretty good!

When I went down to the beach on Saturday ( a 3 minute walk from the caravan) I forgot to take the bag with the tails – so flew the blue parafoil without any tail. Light but steady wind meant it flew very well, though very sluggish when I raised the camera with it.

The blue parafoil was amazingly responsive – I could let it drop down to not far above the path to the beach. Then, just pulling in a few metres of line, I could get it to climb rapidly up to nearly overhead. I think the shallow aerofoil shape has given it this responsiveness – much more than any of the other parafoils I’ve made.

Finally, a breeze…

Kite is powering, pulling strongly, as it moves to the upper left of the screen. Note the fins at the bottom, both left and right, billowing out…

After taking various kites on the bike with me to town, I finally got a day with at least the beginnings of a kite-flying wind yesterday.

I put the purple parafoil up, since it hasn’t had any flying for awhile.

The kite is a scaled up version of the first parafoil I ever made, and has quite a deep aerofoil. That gives it a bit more drag overall – the newer blue parafoil has a much slimmer aerofoil.

My main dislike of it is that the outside bottom fins are made so that rather than having three fins down the line, like the ones in the middle, the outside has a larger bottom fin that takes the place of two. It seems to blow out somewhat in flight, and just doesn’t look as nice as the design of the blue kite.

But it flew well, and without any tail to compensate for errors – as a kitemaker, that is one of my ‘measures of success’ in making a parafoil. You can, and generally do, have to have some sort of tail or drogue on parafoils. But if they are made well, they can and should be able to fly without, I say!

Kite day coming…

Though I’ve not referred to it here much, there is a kite day this coming Sunday at Fergusson Park for Matariki. I’m not usually much for kite days, as I’m not overly social (!) at the best of times.

There is a predominance of massive (nothing wrong with that…) ‘kites’ that hang from a pilot kite, rather than fly on their own and finally – made by other people. I think I’m good evidence that you don’t need to know how to sew to make kites – just don’t look too close at the stitching!

But this will be the first I’ve been to when I’m only bringing soft kites. No sticks (apart from several that are part of the kite messenger).

3 parafoils
4 panflutes
6 parasleds
9 reels of line
1 picavet rig with camera
1 static dropper rig
3 misc droppers
1 ferry with dropper bag
hammer and stakes
1 set of night lights

I’m not counting the silver flowform yet – it hasn’t flown properly. And the one bit of wind that it could/should have used makes me think the aerofoil shape is not right – and I am in the process of putting some ‘darts’ into the foils near the leading edge, trying to give it more lift than it currently has.

Semi-success with the ferry…

Thursday I met up with Averil at the waterfront after she had an appointment in town. Though the wind was not ideal, we managed to fly the blue parafoil and some mixed results with the ferry and dropping things.

Tauranga Harbour and a pretty sharp southerly wind.

I had carried all the kite gear there from home on my ebike. edbikes.co.nz I’m making my EdBike work for its money…

The kite was biasing to the left, to the point that it would lose the air into the openings at the top – and then collapse to the ground! So I did a bit of line trimming. By the end of the session, it was pretty stable.

The ferry is something of a hassle to set up and work with in the wind. But I launched it up probably a dozen times. “Ideal” would be the ferry goes up, hits the stopper, drops whatever, and returns down the line. I did get that a few times – but also had real issued with the trigger point on the kite getting caught up into the wire that runs through the polystyrene ball that is the stopper. I don’t think it really needs that ball – I’m going to replace it with a piece of pool noodle.

The sail on the ferry probably could do with a bit of tail of its own. It has a tendency to swing about, and even start wrapping around the line. But I’d say the stopper issue above was more significant – get that fixed and all might be well…

I had reasonable success with just sending the ferry up, letting it trip, and fall back down the line. I did that on its own a few times to confirm that it could function well on its own. Now just to get a better way of carrying the payload, I think.

A ‘less than successful’ attempt, with the ferry catching on the stopper, then bringing the kite down. Second video has a more positive attempt, with the ferry rising and falling as it should…

The blue parafoil can fly!…

Last night I made my only sewing contribution – I made a drawstring bag to carry the kite in.

Though the wind was somewhat too mild and somewhat erratic, I can confidently say now that the blue parafoil can fly!

I wasn’t confident to let out a lot of line. Until I get it tuned exactly, it has something of a tendency to over-correct – and sometimes go around in increasingly fast loops until it either crashes or loses its shape and flutters to the ground.

But flying. No doubt at all that it will be a heavy puller – when I didn’t have it tied to a bench, it could feel sort of scary even at low altitudes, pulling enough to be more than I’d want to handle in a bigger wind…

I’m going to see about getting a heap of (cheap) sewing machine bobbins, and try to develop a better ‘tuning system’, a way to easily lengthen and shorted specific towing lines. More to come!

Plans for the blue parafoil…

1982 Edition 3

This .pdf parafoil kite plan is from https://www.kiteplans.org/planos/parafoil4/parafoil4.html, but I have used Google Translate. As you can see, it is about 35 years old, but I liked the approach by the author. It isn’t a plan to tell you how to make it – it just concentrates on quality calculations to create the patterns.

I didn’t use this so much as a ‘plan’ as for the shape of the aerofoil and fins. I relied on an element of trust when it came to some of the maths…

Sewing is finished…

Sophia finished the last of the sewing last night – more than a half kilometer – (more than 1600 feet) of sewing. Estimation is based on the spool of cotton (well, polyester) that was used.

Then I sat on the couch are got/kept Paris the cat’s attention. She enjoyed the bridling process immensely.

So I stretched the kite out on its back, and gently pulled the strings, trying not to disrupt the relative flatness, as the 18 fins gently lifted. I could then, letting the strings run through my fingers, position the soon-to-be towing point above the kite. I’m aiming for about a 22 degree ‘angle of attack’, the angle the face of the kite will be, based on the pull of the line below it.

Pulling the 18 lines up to set the towing point. May need to do this better, or at least fine tune the lengths when it flies…

That shallow angle of attack, combined with the relative ‘thinness’ of the aerofoil shape that I am using will produce, I hope, a really high performance pulling kite!

The bridling I did last night was pretty rough – I’m not expecting immediate success at stable flying. It has a lot of fine-tuning to go before I can teach it to fly (heh, heh).

First flight might be later today…

Nearly finished!

We had some time off from making the blue parafoil, what with life and other commitments…

But got seriously stuck in yesterday. We had completed the stitching to attach the 18 ‘fins’ from the face of the kite, as well as the 11 ‘aerofoils’ coming off the back of the face.

Yesterday was a lot of repetition, pinning and sewing the aerofoils to the back square of nylon. This involves sewing a curved shape to a straight line – not massively difficult, but I reverted to pinning rather than ‘hot tacking’ the nylon with an old soldering iron.

Ready to sew the final vertical seam, with the other 9 ‘pockets’ rolled up and inside the last outside pocket.

So now ready for the last vertical seam. In order that the rough edges of the seam will be inside the pocket, the entire kite is rolled and folded so that all of the kite is inside the final pocket. The process is sometimes called a ‘burrito roll’ by kitemakers.

When I did my own sewing in the past on parafoil kites, I would often be a bit sloppy, and end up sewing through layers that I should not have – and then having to go back to unpick it to try again. With Sophia’s vigilant eyes, I have been more exacting and methodical in the folding back and pinning.

I’ve already got the lines ready to attach to the 18 tow points on the fins, so after this last vertical stitch, the kite will emerge from that last pocket like unrolling a rolled up sock. Then one last seam across the bottom to close off the trailing edge of the pockets.

First flight maybe today? Something of a deadline, as Sophia will be leaving tomorrow…

Almost ready for the more challenging sewing…

Each of the 18 fins have a small loop to attach the 18 bridle lines. We have extended that line from the loop back to the front piece of the kite, to better distribute the pulling force to the kite…

We’ve got the (31) pieces of the parafoil ready. So far the sewing has been pretty straightforward, so to speak. The next job will be to join both the front fins and the flat edge of the aerofoil shape to the 1.5M square front piece. That will be a combination of tacking and pinning to make sure the seams get all the layers they should. But the final sewing, putting the 1.5M square back piece onto the curved side of the aerofoil, creating the pockets, will be the most demanding. Not only do you have to contend with sewing to the curve, but also making sure seams on both left and right side are inside their pockets. And the last seam, as I remember from previous parafoil constructions, involves putting the entire kite into one of its pockets, and having to use extra care not to stitch through any of it when the seam is done. I have confidence in Sophia’s sewing expertise!