KITE BUILDING DIARY

Surfplan CAD software was used for the layout plots.

8.5 sq. m  Kite design & Foil shape from  Zero Prestige

DIARY OF EVENTS (Most recent first)

Friday 16th September 2005
New panel designed with Zip & Velcro to replace ripped section. Lots of unpicking of stitches.
Started to sew in new panels. Not much success with the Venture tape, (see below).
I have my doubts whether it would hold Cuben Fiber on its own. It sticks to sand very well but
not pieces of fabric unless you sew it as well. Any way it looks like you can now buy Kites out
of Cuben, cheaper than the material itself.

      (Click thumbnails for detail)
Detail of new closure system on LE centre panel

Wednesday 24th August 2005
Calamity with the kite on Rhosilli beach. Put too much pressure in LE bladder which caused the velcro fastener to open. The bladder then proceeded to rip the LE Dacron. Design problem!! Need to replace ripped panels and re-design the closure. Luckily the blader being oversize appeared OK.

17th July 2005 Kite Tests: Blackpool, Southshore

Video Downloads
                      Windows Media (lower quality) kite8-5-1.wmv  1.3 Mbytes
                        mpg-1 (click to save as)           kite8-5.mpg      8.0 Mbytes

11th July 2005 Re-design odd & ends

Rotated LE valves for better access and inserted plastic washer under strut valves
to prevent bladder forcing out through wide hole. The valves heads also have plastic
dust cap and foam protection secured by Velcro.

        Click to enlarge

Twin LE Valves                 Strut valve with (blue) washer.

Due to problems with  rigidity of corner between LE and struts at the tips, I decided
to remove the struts and replace with battens. The battens were made using same
construction as kiteboards. ie. Herex core/Carbon pre-preg sandwich. This gives
high rigidity and low weight. The ends were left uncovered to expose the foam core.
This was to prevent the Carbon bursting out the Dacron pockets sewn at the tips.

Battens out of bag        Pocket with Batten inserted and secured by Velcro
                                       (Click to enlarge)

29th June 2005 Cuben Fiber Samples arrived

   Click to enlarge

               
    CN2 Canopy?                               CN5   LE & Struts?

Certainly looks interesting, but the colour is a bit drab !!
The supplier suggested sticking the stuff together with  "Venture" tape
as no load was shown on stitching done on the seams using this tape.
(Apparently its very difficult to un-stick the Acrylic based adhesive also)

28th June 2005 "FLIGHT TEST"

First test of Kite, in gusty wind 15-25mph. Not ideal, but showed up a problem
with the struts on the tips. I was originally going to use battens, but as the LE
bladder was oversize, I decided to extend it into struts at the tips. My corners
need some modification as the bladder is pinched slightly due to the diameter
reduction at the 90 deg join. This causes a reduction in stiffness at the corner.

Click to enlarge (frame grabs)

27th June 2005

Cut out strut bladders from Tuftane and assembled valves.
Welded seams using iron set at 160 C. Pressure applied to baking paper
and Tuftane with an edge of aluminium angle covered in Teflon underneath.
(to avoid sticking). This seemed to work rather well as there were no leaks.

       
                                     Click to enlarge images

Prior to sealing the bladders, the valves were assembled inside, with a piece
of sticky back Dacron on the outside for re-enforcement. I gave up on using
the PVC arm-band valves as they were too difficult to seal properly.

  Click to enlarge images     

Instead I cut of the bottom of a tubeless car tyre valve and inserted it through
a 5-8mm cable gland with one side cut down. (Maplin Stock No. JR76).
The seal on the inside was made by an O-ring removed from a Speedfit Coupling.
The Nylon washer was used on the outside to tightened down onto.

15mm Speedfit water pipe coupling

Remove collet and extract O-ring and Nylon washer, (x2).

20th June 2005

Decided to try the AIRTIME oversize bladders for the LE as I was short on
material and time to make one up. They arrived from KITESURFARI within
a week from the USA and were carefully threaded into the LE from the centre opening.

Unfortunately I had positioned the valve holes too near the canopy, which made
full inflation nearly impossible as they twisted round. The solution was to patch
over the holes with sticky back Dacron and remake two new holes.
( Airtime have two centre valves only one of which was activated.)

18th June 2005

Finished sewing  the Kite at last, using up 600  metres of Polyester thread!
All that remains is the bladder construction.
Here is a aerial view of the final kite un-inflated. (Composite of 3 images)

Total cost, so far, less than 100 GBP

. Top

Underside

15th June 2005

Finished construction of LE & ribs. Used double sided tape to hold Dacron
together whilst it was being sewed. Proved a real challenge to sew the curves
on the ribs as it is so stiff. Started to sew the canopy onto the LE which again
is tricky as the Nylon stretches whilst the Dacron does not. Finally solved the
creep problem by tacking down the join with sellotape, sewing straight tacking
stitches, removing the tape and sewing triple zig-zag over the straight stitching.

    Aligning the LE re-enforcement with the canopy.
                                           Canopy rolled to allow feeding through sewing machine.

8th June 2005

"Tuftane" (Polyether TPU) sample arrived from Permali

    Tuftane TFL-1EAN 100 micron
                                       Click for a larger image

I believe its what Cabrina use in an 80 micron gauge.
Permali were quite generous with the sample so I can run
some tests on its suitability for the bladders.
It appears to have lower temperature sealing properties than Nylatron
Unfortunately Permali only sell it in 70 Kilo rolls !!
If anyone wants to go in shares for a roll, contact me.

Now have some 3.3 oz Dacron sailcloth and have finished cutting out
the LE and ribs. They do it in colours but I ordered the white as its fairly
translucent and easy to trace the pattern on to.

29th May 2005

Sewing the Canopy Panels              Close up of Triple Zig-Zag Stitch

The Canopy, (less the panels at tips) Scalloped side is the edge joined
to the LE reinforcment.

24th May 2005

Beginning to think the material I've got too heavy for the canopy and not
stiff enough for the struts & LE. At least it didn't cost anything and its good
for practice on. Might try some "Cuben Fiber" for the next one if I can get some.
Cuben's CN5K18 0.85 oz for the Struts & LE and CN2K.08 0.35 oz for canopy.
Waiting for some samples.
  

    Traced pattern of a strut                   Stitched seams

    Nearly finished strut with Elastomax bladder partly inflated.
    Blown up by lung power only.  Not certain yet if it will take 10 psi.
    Needs Velcro over the inflate valve.

22nd May 2005

Constructed test bladder using Elastomax with valves cut out from arm bands.
Seams hot cut & welded, reinforced with Aerovac blue flash tape.
Appears air tight but need to improve on seal. Any creases in film can cause air loss.

Detail of valve                                      Test Bladder

17th May 2005

Acquired very cheaply a lot of ripstop material that looks very similar to that used in kite construction
Acquired Surfplan for the layout plots and a 8.5 kite design from the Zero Prestige website with instructions.
Plotted out 169 A4 sheets and stuck them together.
Tried cutting out material with hot knife from a pyrography kit. Seems to work OK.
Bladders to be made from   vacuum bag material  from board construction  (Aerovac Elastomax)
Valves cut from from kids swimming arm-bands, (there are 4 on each pair)

Templates & Material 3oz/sq.yd  3D Simulation (Surfplan)          Using hot knife to test seal & cut
(Colours aren't too hot)                  New Colours (Dacron LE)       (Elastomax for bladders.)