Greetings - I have the complete range of 2021 NP Free Flight sails, like them (previously on Sailworks Flyer). The Free Flights are higher aspect and have much more draft than the Sailworks Flyer. However on the Free Flight's when going upwind fully powered to overpowered I'm experiencing a lot of mid section leech flutter Still chasing the solution with different downhaul settings. Anyone having similar experiences or solutions? Masts are NP from 2014 to 2017. Thank you
All the best,
Blunt

Did NP change the bend curve on the 2021 masts for the 2021 sails? Have you adjusted the battens per manufacturers recommendations? Try contacting NP.

I've only have got the np freeflight 5.7m
also experienced leech flutter and also mid sail panel flutter with the sail.

In an attempt to try something I moved masts from 2021 SPX 90 rdm to 2021 TPX 100 Sdm, by changing the rdm to a sdm cam.

Contrary to NP saying the mast bends are the same.. the Sdm is much stiffer through the boom and mid leech area than the rdm of the equivalent size.
The sail is much more powerful, has a more forward draft and depth.
my boom length drops by 4cm moving from rdm to Sdm.

I prefer the Sdm for this sail size as it's my largest I use with my FoilX 125.
so I want a powerful sail to push the Starboard HA wings I'm now using.

The leech flutter really hasn't gone away, but the sail is great to use.
I prefer it the sailworks flyer in a similar size, as for its size it's much more powerful.

I wonder how much real world development and testing went into the 2021 range due to Covid restrictions.

Ive also got problems with my 8m v8 flight:
there's also a mid panel flutter, similar to the freeflight- which to me indicates that the monofilm panel hasn't been designed correctly
The cam rotation is really bad on the top cam above the boom... even though it's on a 2021 spx 95 mast.
I didn't feel the desire to spend ?650 on a new TPX 490 ... even if I could get one.
Various fixes were suggested, which by altering the length of the mast extension the perimeter tension was changed. This helped a little but still wasn't satisfactory.
I eventually unstitched the inboard plastic batten end, which the cam rests on, through the luff zip pocket.
I carefully cut the luff panel and restitched it 5mm back in to reduce cam loading.

The sail rotates perfectly now.

Presumably this would have been sorted if the sails had been out on the water, rather than just the photo shoot at Lake Garda.

Stick on popsicle sticks to the leech with a piece of tape to make some mini battens. Might not look pretty, but will probably fix your problem & increase your sails durability (and also reduce drag! Leech flutter = considerable drag). If it works you could consider having something similar done professionally.

These freefoil sails (also from other brands) have the problem because of the huge panels & few battens. I dont understand why not all brands put mini battens at the leech in high risk areas to prevent flutter. Probably a weight thing.

From the pictures at the NP web site, it looks like the Free Flights have 2 mini battens in the top panels. They also seem to have quite a lot of looseness, which is typical for other NP sails.

The most similar sails I have used are old North Idol freestyle sails, which are also 4-batten sails. Most sessions, they are great, without any noticeable flutter. But I remember a couple of sessions with strong gusts where the noise from the top panel was pretty bad. Releasing downhaul helped somewhat, but the main problem was that the sail was just way too big in the gusts. I never had the same problem with a 5-batten freestyle sail (Severne Freek).

Comparing a 3-cam foil (Foil Glide) sail to a 3-cam freerace sail (SwitchBlade), there's a big difference in looseness. My speeds relative to the wind are similar with both sails, and they work beautifully for what they are intended for (but much less so when switched). The much tighter foil sail reflects that the wind-height gradient is steepest near the water surface. By moving the sail up a foot or two on the foil, you eliminate the need for a lot of the twist you need in sails for finning.

Looking at the picture from the NP web site, they show looseness almost all the way to the mast near the top:

Even in the middle panel, the looseness goes about 3/4th into the panel. IMO, that's too much. For comparison, the Severne Freeks have shorter mini battens, and work great for foiling when trimmed so that the looseness ends where the mini battens end.

Some sail designers seem to have a pretty hard time to adjust their designs for foiling. Some of the earlier foil-specific sails were very low-end oriented and often described as "unstable at the high end". Could be that NP, coming from the soft-top-mast, "lots of loose" end of the spectrum, has to adjust more than others. I'd put the Free Flights in masts with harder tops and see how they work.

Hmm, I suppose you are correct boardsurfr! I think minibattens only really help if they extend further into the leech than the loose cannopy does? If you get my meaning?

I have the V8 Flights 7.0&8.0. Only used them once each and not noticed any issues. Both on SPX 90 masts, 460&490. I'll keep and eye on the leeches. I rigged them to spec DH & with adj OH so maybe +2 there.

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BSN101 said..
I have the V8 Flights 7.0&8.0. Only used them once each and not noticed any issues. Both on SPX 90 masts, 460&490. I'll keep and eye on the leeches. I rigged them to spec DH & with adj OH so maybe +2 there.

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BSN101 said..

BSN101 said..
I have the V8 Flights 7.0&8.0. Only used them once each and not noticed any issues. Both on SPX 90 masts, 460&490. I'll keep and eye on the leeches. I rigged them to spec DH & with adj OH so maybe +2 there.

Nice boom

Man those sails are pretty..

Nice looking sail, but would not get a sail without 100% X-ply, I hit those panels with hands and knees occasionally and would probably break out a mono-film panel with my weight of 86 kg.

The NP sails are quite robust In comparison to some manufacturers without any foot reinforcement... I've heard some longevity issues with the severnes iqfoil sail

There is very limited choice for large recreational foiling sails... what else is available on the market without having to get new masts to match the luff curves?

Never mind the restriction in being able to get any new equipment anywhere at all.
Ive had an order for a NP freeflight 4.8m in the UK, for 3 months now, and it will hopefully arrive this week.

The NP range seem reasonable. .. they are powerful for their size and work well.
They hopefully will evolve and become more refined, as perhaps more R and D time is spent on them.

It's the panel with the np logo, which seems to make all the noise

Tricky to tell from the pics but the second batten from the top in particular looks a little tight maybe. Something a little odd about the vertical lines running between the 2nd and 3rd battens, loosen them both a touch and see what that looks like.

I've a 2020 6.2 V8 which is also really difficult to get a nice set on, wondering if they've been having some build consistency issues over the last couple of years.

On the foil specific sails, while there are some nice ones out there I'm not convinced they're that necessary other than for the high end racing sails. I use a 7.7 and 6.2 regular V8 for blasting cruising sailing and then switch to Atlas and Combats for windier freeride stuff and they perform just fine. I've tried the V8 flight and it was nice but not enough of a difference to make me want to switch.

Your batten tension might be too high. I recently tightened the battens in my 10 month old Severne Glide 7. Before tightening there was no leach flutter. Now there is. I'll try backing off the tension in the battens and report back on whether it works.

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RuddeBos said..
It's the panel with the np logo, which seems to make all the noise

Very long harness lines