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light wind trim?

Posted: Sun Sep 10, 2017 10:01 pm
Now that we are finally getting some lighter winds I am trying to learn to use my foil kites.

In super light wind, should I be trimming the kite closer to all the way out?
Is there a rule of thumb for trim in lighter winds? What about stronger winds?

There are brief periods where I feel like I am flying well, but when I am not getting enough out of the kite I can't tell what I am doing wrong. Maybe it will just take time but right now I am at a loss as to which way my trim needs to go. Any hints?

Thanks

Re: light wind trim?

Posted: Mon Sep 11, 2017 5:43 am
You don't explain the issues you have. Backstall? Collapse? Won't turn?
So for now I can only recommend something counter-intuitive for newbies: depower the trim and let the kite breathe. Foils hate to be over-sheeted.

Re: light wind trim?

Posted: Mon Sep 11, 2017 7:48 am
"Kite breathe" means keep kite flying forwards (not locked in single place in wind window). Fly arcs in marginal wind with bar in sweet spot for the true wind. Oversheeting will reduce kite forward speed and produce less power than forward flying kite with a gentle touch. From lift equation you see that speed has squared effect for force where AoA/Camber (lift co-efficient) has only linear effect on force. So optimize both to have best speed for the kite and enough lift AoA to get the power to get to speed & plane.

Re: light wind trim?

Posted: Mon Sep 11, 2017 7:59 am
I fly all of my foil kites sheeted in (depowered) avoids backstall and keeps it moving and producing power.

Re: light wind trim?

Posted: Mon Sep 11, 2017 8:46 am
socommk23 wrote:
Mon Sep 11, 2017 7:59 am
I fly all of my foil kites sheeted in (depowered) avoids backstall and keeps it moving and producing power.
You meant sheeted OUT surely?

Re: light wind trim?

Posted: Mon Sep 11, 2017 9:56 am
alexrider wrote:
Mon Sep 11, 2017 8:46 am
socommk23 wrote:
Mon Sep 11, 2017 7:59 am
I fly all of my foil kites sheeted in (depowered) avoids backstall and keeps it moving and producing power.
You meant sheeted OUT surely?
In sailing the sheet is a rope. So I see it as the depower rope is the sheet. Pull it in to depower. Sheet in.

That's how I understand it.

Could be wrong

Re: light wind trim?

Posted: Mon Sep 11, 2017 3:36 pm
socommk23 wrote:
Mon Sep 11, 2017 9:56 am
alexrider wrote:
Mon Sep 11, 2017 8:46 am
socommk23 wrote:
Mon Sep 11, 2017 7:59 am
I fly all of my foil kites sheeted in (depowered) avoids backstall and keeps it moving and producing power.
You meant sheeted OUT surely?
In sailing the sheet is a rope. So I see it as the depower rope is the sheet. Pull it in to depower. Sheet in.

That's how I understand it.

Could be wrong
The convention with kites is to refer to the bar as the sheet since pulling on it "sheets in" the AoA of the kite. If you grab the example from airplanes, pulling the depower rope is "trimming" your wing to fly correctly within a given range of bar throw.

That being said, I'm confused whether the OP is talking about pulling the depower rope or actually tuning the bridle/speed system for a light day. Both are possible, one requires a bi more expertise to do correctly...

Re: light wind trim?

Posted: Mon Sep 11, 2017 4:51 pm
Foils need to be depowered at the trim strap in light winds. Also in general u need to push the bar out a little bit on the upstroke . I have this problem when i lend guys my foil kites first thing they wanna do is let out the trim strap. Wrong.. like everyone saids a foil kite needs to move to generate power. because of the bridle lines connected to the trailing edge they are much more sensitive to back line pressure so dont be afraid to depower a little u wont be losing power but gaining power as the kite moves freely.

Re: light wind trim?

Posted: Mon Sep 11, 2017 5:03 pm
From what you guys are saying I think I am being too hamfisted. And stalling the kite by pulling in the bar too much.
On water starts I usually get up by diving the kite and pushing the bar out. But then I often lose power/speed and drop back to the surface.
While riding sometimes I just slow down, I don't know why, and lose momentum and power. The thing that is frustrating me is I will trim out (longer front lines) and try that for a while, then trim in and try that for a while, but I don't seem to do better either way. I guess I just don't have enough feel yet to know what I am doing wrong.
The weird thing is I usually do great on jibes. I have no problem down looping and keeping speed and power through the turn. And on every 4rth or 5th waterstart or so I just take off and fly away no problem, plenty of power.
Turning

Re: light wind trim?

Posted: Mon Sep 11, 2017 5:32 pm
It's also possible to sheet the kite in so that it's stalled in the wind window, then ease the bar out and the kite will pop forward to the edge of the window and pull you out of the water.