Kite Making - The Kwat

The third project ( once you start there will be no stoping) was from Stunt Kites I (Servaas van der Horst/Nop Velthuizen) - the Kwat quad line kite. I was attracted to the shape of it and, since I like quad line kites, felt it would be another good one to have. I also wanted to practice more sewing, as well as making bridles - so all things considered I started making this.

These are my experiences of making the Kwat and are intended to complement to published design.

The Design

[Kwat panel plan]

I started by deciding on the layout of my panels - after a few attempts I arrived at this - using material left over from the Papillon project.

I wanted to be able to tell which was up the kite was, hence different colours on the left & right, other than that I wasn't too bothered.

The Sail

[Kwat panels]

I decided to hot cut the material this time - I made a template of the equilateral triangle out of a cereal packet, allowed for a double seem on each side, then cut it out using my modified soldering iron & metal ruler. This worked fairly well - I think I need a better cutting surface (currently using melamine coated chipboard) - and gave a neater edge than simply using a sharp craft knife. It did take a while cutting all 12 panels out.

I then assembled them (as per the instructions in the book) into half hexagons (using a double seam), then into the whole.

[Kwat half wing]

On one hexagon I tried putting the hem around the edge for each half, then stitching the halves together, the other I assembled the entire hexagon, then stitched the hem. Just to see which was easier. The answer: about the same - but a little bit easier with the half hexagons as there was less material to feed around the sewing machine.

[Kwat wing]

Once each hexagon had been completed I overlapped by 14cm, and then stitched them together along the hemmed edge of the overlap.

[Kwat reinforcement] One of the most confusing bits of the published plan was here ("On the corners C stitch a small strip of spinnaker cloth crosswise.") - what you actually have to do is stitch some reinforcement where the two hexagons overlap as this is a real weak point (lot's of stress whilst in flight). I just used two thin strips of Dacron about 5cm long and .5 cm wide in a 'X' shape, stitched up and down a few time (this is actually shown in Fig 5 in the book, but you would never guess from the text!).

The tunnel on the back for the horizontal spar is difficult to stitch due to the thickness of the sail where all the triangles meet - as you can see from the front view opposite. One thing I changed - the 'tunnel ' on mine is open in the center - this allows easy access to do the bridle, and for the spilt central spar (see below).

[Kwat center stitch]

The the 'lace' (or tie) I tried to use some ripstop, but it really was too fiddly to do well. I also stitched it to the tunnel fabric before I stitched the tunnel to the finished sail.

[Kwat tie]

The corner reinforcements were fiddle to make - I made a cardboard template of the shape I wanted for the Dacron, then cut out the 10 necessary (again hot cutting). I then made the strips of fabric that will hold the spar arrangement in place by folding over a 8x3cm stip. This was very time consuming and fiddly to do, especially the stitching, but once done seemed OK. All 10 points are done the same, by the way - something not made clear in the book.

[Kwat corner reinforcment]

I then threaded some short lengths of line through each corner loop and tied with an overhand knot.

Finally I used the soldering iron to create two holes at each corner - either side of where the spar would go - these are to pass the bridle lines through sail and around the spars themselves, and the slot in the center of the kite to allow the central bridle line to go through.

The Spars

For the spars I assembled as in the book, but found that the central spar at 150cm was going to make the kite very hard to transport for me (i.e. would not fit into my kite bag). I decided to make it out of two 75cm spars connected via a 6mm ferrule (shown on left in picture) and a short length of 4mm carbon glued inside the other spar (shown on the right). I guessed (well at least hoped!) that the central bridle would prevent the spars from breaking.

[Spars] One slightly annoying thing was that each cross spar was 82.5cm - however I bought 160cm lengths. Therefore I could only get one spar from each, with a lot left over. This was another reason why I split the central spar into two - I could then reuse these off cuts.

The central spar, showing the end cap (made from a piece of PVC tubing) help in place by a bungee cord. This is a departure from the book - partly because I didn't have enough 6mm nock end caps as per the plan. However I think this works better for the central spar - it seems easier to keep the sail in tension.

[Kwat end cap]

The Bridle

[Kwat bridle detail] I found this very difficult to get right - partly from my lack of experience in making bridles, partly from the cheap (and very thick and very stretchy) bridle I got from Decathlon, and partly (it must be said) from the confusing instructions in the book.

It's comprised of two bridle lines going end to end, attached in the center, with 4 lines at the top and bottom of each hexagon. The flying line attachment points are in the center of these 4 lines (called 'V' lines in the book). However a short section of bridle goes from each of these 'V' lines (point 'L') to the central lines (point 'Z') in order to make the flying line attachment points mid way between the two spars, but (and this is the key bit I think) level with the edge of the kite.

On my first attempt I decided that these short length of lines weren't necessary - however this made the kite unflyable - simply spinned in the sky then into the ground. Attaching the flying lines directly to the spars actually improved things, but (as further experimentation proved) caused the central spar to snap at the ferrule (to be expected really....) whilst not really improving flight.

I spent a long time trying to think of a more practical bridle arrangement but in the end gave up and retied it as instructed in the book. This time I relied upon me measuring each length of bridle and ensuring all 4 sections were the same. I but the 4 short lengths in - attached to one loop on the 'V' line (point 'L') via a larks head knot, and to the central bridles (point 'Z') via a slip knot.

The flight was much improved (in that it did fly!) but I feel there is still room for improvement (see below).

[Finished Kwat]

Improvements

Better bridle lines - cheap stuff is not worth it - needs to be thin, but not stretchy. Will make it easier tying the knots.

Double seams in the Kwat make it hard to stitch the 2 halves of the Hexagons together, and especially when you try and stitch the tunnel to the back of the kite.

And speaking of the tunnel..... I can't really seem why it's there at all. Maybe something in the center to stop the central spar slipping up or down? And if it's really got to be there I wonder if somehow doing it whilst stitching the two halves together would be better? Something to work on......

Those 'lace' ties in the center of the hexagon panels to stop all the spars moving around are a pain - I guess a rubber 'O' ring should work a lot better - both in ease of construction and in ease of assembly on the flying field.

Make the central spar bowed - tie a bridle line from end to end to put a slight bow in it (as in the Papillon) - the theory would be that it would present a more areodamic profile to the wind, and would improve the flight. At least that's the theory - which of course may be wrong. It's worth trying........

Links

Kwat Info