ELF Product Support Questions

[Mossy 757]

I have a 15m J5, it's a heavily used kite and I'm the third owner. I can tell from what use I've gotten out of it that it's a great, balanced kite.

It has been modified over time and I want to put it back to as close to a factory a tune as possible. I got some measurements through a friend at a regatta but want to confirm that I'm looking at this the right way.

"Power Rib = N2
0, -25, +60, +300"

What I've discerned here is that I hold the line attachment knots even at the "control bar" end of the bridle, then pull the canopy tight at the 2nd power rib and measure against A:

A is the baseline
B should be 25 mm SHORTER than A
C is 60 mm longer than A
Z is 300 mm longer than A

I've drawn a terrible picture to try to explain what I'm looking at. If I'm way off base or if someone has a better guide for how to do this, I'm all ears. Both pulley lines need to be replaced, as do a couple of worn out pigtails, so ultimately if I had a complete line diagram (in English) I'd be able to figure this out myself, but I've only seen that for FS and Ozone, never Elf.

Help?

[holden]

you are on the right track. check out the pictures in this post:
http://www.foilzone.com/phpbb3/viewtopi ... =45#p91108

if you replace the pulleylines you have to recheck the trim.

h.

[holden]

how to set up the kite for trim check:

[foilholio]

What is wrong with how the kite flies?

The reason I ask is that setting a kite to standard lengths wont necessarily give the best flying kite.

The adjustment of mixers usually revolves around an even setting. Where all the bridles from the kite meet the mixer and all match each other at some combination of front and rear line adjustment.

The mixer is designed to depower the kite, achieve a flight profile and relaunch or reverse flight. If it doesn't do any of these there is something well wrong with it. All of these characteristics can be altered with how the mixer is adjusted. Of particular importance is the flight profile. A lower camber or negative camber will be more stable and have lighter bar pressure. A higher positive camber will have more lift, drag, less stable and with higher bar pressure. A neutral camber or profile will have the best Lift to Drag ratio, and will go upwind easiest. Profiles that radically pull on BC or Z and leave slack in the others will fly poorly. In all of my kites the progression of tension is B C then Z. They engage relatively close to each other with Z engaging just before the wing will stall or reverse fly.

Z is of most importance. As it usually only receives very light duty and tension, it will shrink the most. If it has shrunk a lot you can see the trailing edge of the kite becomes kinked a lot, the kite will also be unstable, tips collapsing etc with higher bar pressure. Lengthening it will resolve a lot of kite problems.

[foilholio]

Locking the mixer together like that is a good way to check for asymmetry. Dont forget to check your front lines as well! You can usually stretch most things out.

[Mossy 757]

Thanks guys...does anyone have a full line plan for a J5 15m? What about ABCZ measurements from power ribs other than 2 so I can check the whole bridle?

[holden]

this method is only to trim the mixer, so you only check the 2nd power rib and adjust the knots at the mixer. i will check if i find a photo to show which knots these are.

you can restrech each bridle line. you need to pull at each attatchment point with a certain force (between 5 and 10 kg). always stretch one point on one side and then the mirrow point on the other side right after and check if both are stretched to the same length. after that you adjust the mixer with the 2nd power rib.

there is no need to recheck with the line plan, the values would be too much off anyways.

h.

[holden]

this is where B and C are altered:

[holden]

this is where Z is altered:

[Mossy 757]

Thanks Holden!