Friday, May 24, 2013

1.7m yellow rokkaku - 20 sq ft

This scaled-down rokkaku is designed for KAP, fitting in between the 9ft Levitation Delta and the 28 sq ft 2.0m white rokkaku.

Like the 2.0m kite the size ratio is 5:4:3. This means 5 units high, 4 units wide and 3 units between the cross spars. The top and bottom triangles are 1 unit high and the bridle points are 1 unit out from the spine. For this kite 1 unit equals 34cm making it 170cm high, 136cm wide and 102cm between the spars.

Woven cloth has least stretch along the WARP fibres (down the length of the roll). The WEFT fibres (across the roll) may not be as straight or as strong, and the BIAS (at an angle to the fibres) gives the most stretch. Cut out your panels so that the WARP fibres are parallel to the outer edges of the kite. This is the reason 5 or 6 panels are used for the rokkaku.

Ripstop nylon from Emma Kites is 155cm wide which is wide enough to cut out the rectangular panel (forming main body) in a single piece with the warp threads aligned correctly. The top and bottom of the kite still need to be made from 4 right angled triangles.

I bought a 5m pre cut length for US$21 (free postage) and used less than half.  I did notice that the WEFT fibres run in quite a pronounced curve across the roll, maybe that is why it was so cheap. However the kite still flies perfectly.

Spars are 82.6cm Skyshark Camo P4X tubes from Kites and fun things. US$3.50 each with US$42 postage. To spread the freight cost I bought 20 of them with carbon fibre rod ferrules (3.75" x 0.24") and vinyl end caps (0.281"). That will be enough for another 3 kites or lots of breakages.

I did the seams a little differently this time for a neater finish. Virginia tells me the correct term is flat fell seam. Two panels are sewn together front to front along the marked sewing line (20mm in from the edge) then the panels are opened out and the 20mm seam folded over to the left or right. About 12mm of the underneath seam is trimmed off, then the top seam edge is folded over and under the trimmed edge then sewn down close to the folded edge. This gives a neat finish with no raw edges.
For the first time ever I also used the correct thread colour top and bottom for the entire kite.

I'll do some instructional videos on the sewing details soon. Stay tuned.

The patches, webbing pockets and velcro loops are all the same as the 2m white rokkaku as are the folded hem edge and bridle.

Here is an A4 size plan for the 1.7m kite. Feel free to download it for your own use.

Timelaspe of cutting out and sewing the 1.7m rokkaku. 4hrs in 80seconds

Here's the first flight in Bft 2

Here's a test flight in Bft 4+