Lars Madsen wrote:
One easy method could be stretching some (or all) A bridle line in the problem area or at least to check that they have not shrinked. Wingtips are less loaded than center of the kite so that may be the case. On the other hand, short wingtip area chord gets more AoA change from B to Z, so perhaps they stretch (or shrink less than A), resulting folding wingtips.
I would first stretch tertiary, then secondary and if needed primary bridle lines. I think couple of cm's more lenght to A would result quite surely.
I just got a used sonic 11 ( I have a sonic 18 from new 1 year fly perfekt) but this one fly like a hole different kite . the wing tip folding like all the time (the 18 almost never fold ind ) When I measure a and A bridle lines lokes like it about 2 cm to short, if I measure it right? So your ide with stretching A bridle line could be for me. But how exactly do you do that? Take them of an put them on something and pull? and how hart should you pull?
When I got it B was -5 and c - 10 . First time out I put b and c to zero and them to b -2 and c -4 . i am using a naish bar. The way it fly now I dont dare to jump high.
ok there is a little turbulent wind the 2 time i been out.
I just hope that the 11m could be great like the 18m.
11m kite has shorter chord than 18m kite, this makes same bar movement to have greater AoA change in 11m kite. Smaller kite is also more sensitive to changes in bridle line lengths because they are relatively bigger for it. But of course lines are shorter in smaller kite so that balances that.
If your B and C are negative, it means greater camber which means decreased stability, -5cm and -10cm is a lot. If you want more stability B and C should be longer to decrease airfoil camber. So it is possible to alter or preset airfoil camber by adjusting mixer. However there is only one position (everything in level, if bridle is ok) which does not distort the airfoil (or does it optimally). And like I wrote it is not correct to adjust whole kite's camber if problem is only in wingtips.
I would start stretching from the AIII, then A5, A6 and if necessary every primary line in that area. It is good to check B and C too. You don't have to take them off the kite, although in FS it is quite easily done because of LCL's. Thicker lines need more pull of course. Lines have loops in each end, use some rods, weights, larks head knots etc. and measure the results. One trick is to do one side of the kite first and have a testfly to see the effect.
Sonics bridle is good work, it is clear and it has well designed cascades. Problems may occur because lines are thin. Sonic is a kite with compromises some durability and usability for high performance.
All in all, it is best to get back to original lenghts and to concentrate in problem area.