Author Topic: The ART 999 Thread  (Read 56903 times)

bigmtn

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Re: The ART 999 Thread
« Reply #15 on: September 24, 2021, 11:00:27 AM »
Rode it yesterday for first time both prone and wing. The thing pumps amazing. When you push down, there's like a spring that pops you back up. It's fast, so you can cover large areas with minimal effort.

Winging its a glide machine. Perfect for smaller waves and wind bumps. It turns well enough for a big wing, but if I'm in bigger waves I'll obviously be using something much smaller like the 740.

I didn't feel much flex. Used alu mast, but I did feel that bird wing feeling. It just feels like a spring when you're pumping. It just shoots you back up after you press down on your pump. Makes it easier to stay high on the mast.

PonoBill

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Re: The ART 999 Thread
« Reply #16 on: September 26, 2021, 05:25:08 PM »
Okay, so this is fucking weird. I'm not that entranced by tails. I use a 390 and a 340. Had some others, they didn't seem important, so I stick with what I'm comfortable with. but when I ordered my 999 I also ordered a 400, because everyone said it's the one to use.

So I went with that yesterday, and I stalled and stalled until I got going fast enough, and then it was very fast and glided forever. When I pumped it to connect through lulls I absolutely felt the "flappy" thing that others have commented on. I didn't feel that the first time. And when I ran out of wind, and it got slow enough, it would just drop suddenly. Bam. What the fuck is with all the stalling. So I went back to the beach and put on the 390. and now it won't stall, no matter what I do--come up too steep, go too slow--won't stall. but it also isn't crazy fast. It was great, turns better, I don't feel the flappy thing, it's just a well-mannered, fairly fast wing that glides forever and makes jibes easy.

I thought it might all be in my head, so I switched back to the 400 with a little better wind, and I stalled and stalled getting up. Once I was up it was all good until I hit a big lull and it dropped out of the sky despite my pumping, I mean really, WTF? Swapped back to the 390, and it's completely a different wing. I don't get it. What is going on??

I don't trust my head for this, I know I can bullshit myself.  if you've got both tails, please try them and let me know what you think. Could the tail change this thing so radically??
« Last Edit: September 26, 2021, 05:28:16 PM by PonoBill »
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Hdip

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Re: The ART 999 Thread
« Reply #17 on: September 26, 2021, 05:37:14 PM »
Tails make a huge difference. Almost as much difference as a board makes. And the board isn’t even in the water and it’s huge.

VB_Foil

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Re: The ART 999 Thread
« Reply #18 on: September 26, 2021, 05:38:20 PM »
Pono, is there a chance there is a difference in the inherent AOA between the two tail wings?  Sounds like a pretty drastic change. Great find! A buddy of mine is waiting on the 999, so I’ll pass on this intel.
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StephenZ

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Re: The ART 999 Thread
« Reply #19 on: September 26, 2021, 10:10:59 PM »
I don't trust my head for this, I know I can bullshit myself.  if you've got both tails, please try them and let me know what you think. Could the tail change this thing so radically??

I'd also love to hear the answer to this.
I was reading your original messages about it not stalling for anything and thinking that just didn't correspond with my experience. And I'm quite a bit lighter  ???

I am also finding that if you get too slow it can suddenly drop out on you. This make things like tacks more challenging - if you lose speed you go down, really got to drive through it.
I'm riding with a 420, but also rode it with a 400 and from that point of view felt similar.

I'm amazed that a tail wing could make such a difference to this.

Califoilia

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Re: The ART 999 Thread
« Reply #20 on: September 26, 2021, 11:13:06 PM »
Okay, so this is fucking weird. I'm not that entranced by tails. I use a 390 and a 340. Had some others, they didn't seem important, so I stick with what I'm comfortable with. but when I ordered my 999 I also ordered a 400, because everyone said it's the one to use.

So I went with that yesterday, and I stalled and stalled until I got going fast enough, and then it was very fast and glided forever. When I pumped it to connect through lulls I absolutely felt the "flappy" thing that others have commented on. I didn't feel that the first time. And when I ran out of wind, and it got slow enough, it would just drop suddenly. Bam. What the fuck is with all the stalling. So I went back to the beach and put on the 390. and now it won't stall, no matter what I do--come up too steep, go too slow--won't stall. but it also isn't crazy fast. It was great, turns better, I don't feel the flappy thing, it's just a well-mannered, fairly fast wing that glides forever and makes jibes easy.

I thought it might all be in my head, so I switched back to the 400 with a little better wind, and I stalled and stalled getting up. Once I was up it was all good until I hit a big lull and it dropped out of the sky despite my pumping, I mean really, WTF? Swapped back to the 390, and it's completely a different wing. I don't get it. What is going on??

I don't trust my head for this, I know I can bullshit myself.  if you've got both tails, please try them and let me know what you think. Could the tail change this thing so radically??
Only a guess since you didn't state which "400", but since most are using the 400HA on the HA wings where the 999 tops them all..I'm going with that in my WAG.

As such, I think it's the smaller surface area of the 400HA (196.24 cm²) compared to the surface area of the 390 (254.52 cm²) that's causing the stall issues at slower speeds. I find that the higher AR I go with front wings, the larger tail wing I need to ride. For instance, with similar sized front wings - the 910, 880, and 890 - I ride the 380 with both the 910 (6.8 AR), and 890 (6.43 AR)...but need the little extra tail of the 420 with the 880 (7.17 AR).

With the 999 in the surf I felt a similar stall problem during takeoffs when trying the 400HA last time out instead of the 420 which has only a slightly larger surface area (212.63 cm²), but it was really noticeably different.

The stall speed while pumping is still ridiculously high with the 420 and the unsuspecting sudden drop-off is a PITA, and makes it hard to connect waves since you have to keep the speed up when making the turn, and with it being so wide that's somewhat difficult to do.

So tmrw I'm going to throw in the regular/older 400 (291.18 cm²), and see what that will do pump/stall wise, cuz I'm thinking it'll turn just fine or even better being shorter that the 420, and still with some tips...just have to see if it'll be too slow. Should be fun no matter what, looking forward to tmrw morning. 👍🏽😊
« Last Edit: September 26, 2021, 11:33:10 PM by Califoilia »
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flkiter

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Re: The ART 999 Thread
« Reply #21 on: September 27, 2021, 03:18:39 AM »
I've found using the rear shim helps with the stall at lower speeds. I was having the same issue with the 980 V1 and once I added the shim, the stall went away so now I ride all the black series stuff with the shim. I like the 370 with the 999. Rear wings are as important as the front wing. Different stance, weight forward or rear foot, speed that you ride at, ECT.... All those things make a big difference in what rear wings work correctly.

Solent Foiler

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Re: The ART 999 Thread
« Reply #22 on: September 27, 2021, 06:41:40 AM »
Different stance, weight forward or rear foot, speed that you ride at, ECT.... All those things make a big difference in what rear wings work correctly.
Which makes recommendations difficult! Argh, I might just have to see how the 380 works for me and take it from there but it sounds like it's going to be on the small side for me, even at 65kg, unless it's moderate breeze or more...
Keeping a close eye on this thread so thanks for feeding your experiences back everyone. Tempted to order a second, larger tail to pair the 380, to arrive with the 999 though...
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jondrums

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Re: The ART 999 Thread
« Reply #23 on: September 27, 2021, 08:57:31 AM »
I'm willing to bet it has to do with the angle of attack of the tail rather than the size.   For a given tail, I found the need to mess with shims adjusting the angle of attack through .5deg increments to find its ideal setting for the way I ride.  If you're stalling suddenly, go with a bit more shim (more downforce or more negative angle of attack).

flkiter

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Re: The ART 999 Thread
« Reply #24 on: September 27, 2021, 09:32:22 AM »
Different stance, weight forward or rear foot, speed that you ride at, ECT.... All those things make a big difference in what rear wings work correctly.
Which makes recommendations difficult! Argh, I might just have to see how the 380 works for me and take it from there but it sounds like it's going to be on the small side for me, even at 65kg, unless it's moderate breeze or more...
Keeping a close eye on this thread so thanks for feeding your experiences back everyone. Tempted to order a second, larger tail to pair the 380, to arrive with the 999 though...

You'll be surprised with the low end of the 999, I feel it easily has the low end of the 1010. I'm still amazed that it puts out so much glide and lift for such a small wing.

Hdip

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Re: The ART 999 Thread
« Reply #25 on: September 27, 2021, 10:30:42 AM »
I'm willing to bet it has to do with the angle of attack of the tail rather than the size.   For a given tail, I found the need to mess with shims adjusting the angle of attack through .5deg increments to find its ideal setting for the way I ride.  If you're stalling suddenly, go with a bit more shim (more downforce or more negative angle of attack).

More shim to raise the rear of the tail wing? Or to lower the rear of the tail wing?

clay

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Re: The ART 999 Thread
« Reply #26 on: September 27, 2021, 10:47:25 AM »
My best wild 2 cent guess is that bigger tails don't push through the water, they hold altitude and this keeps the front wing from hitting a sudden high angle of attack and immediately stalling.

I despise the 390, but it helps in really light weak wind when I'm desperate and wouldn't be able to fly otherwise.   Reminds me of the slingshot 48 in that they are both super slow and hold altitude.
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jondrums

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Re: The ART 999 Thread
« Reply #27 on: September 27, 2021, 11:03:00 AM »
If you're stalling suddenly, go with a bit more shim (more downforce or more negative angle of attack).

More shim to raise the rear of the tail wing? Or to lower the rear of the tail wing?

yes, raise the rear end of the tail.  This will do a few things: 1) increase the downforce of the tail, which in effect requires you to move forward a little bit on the board 2) because the balanced center of gravity of the board/rider is now further forward - the system is now more stable in pitch. 3) the tail will have a bit more drag


bigmtn

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Re: The ART 999 Thread
« Reply #28 on: September 27, 2021, 02:00:12 PM »
I use a kane tail with mine, no shim.  dropped off foil once while pumping back out, but I think that was more to do with the size of the previous set, and the amount of water that was flowing out the channel that I was trying to pump out.  Winging, I have no problem going slow when making turns and trying to hold my ground while waiting for the next wave to come.  So far I've been very happy with this wing.  Rode it on some easily head high waves with the wing, and never felt like I was about to breach, and have had some of my better downwind pumping/riding sessions.  Really looking forward to an even smaller faster size.

Pono, try the 400 tail with some of the other front foils you have, and see if you have the same experience.  Also try adding the rear triangle shaped shim to the 400... You might just need a larger stab for your size.  Or just go faster all the time  ;D

Dontsink

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Re: The ART 999 Thread
« Reply #29 on: September 27, 2021, 02:42:10 PM »
Trying to see the logic in this,here is my wild A guess.

At low speed (close to stall) the tail provides little or no downforce.Adding shims to make it do so should,on paper,make things worse not better.More downforce on the tail means more load for the front wing to lift plus it creates a pitch up moment that puts you even closer to stall angle.

I recently read an article that talked about airplane tails creating upwards lift at very slow speeds, i think some competition glider pilots have played with this.It is certainly not a safe way to fly but it surprised me that it was even doable.

Maybe the ART999 tail that is giving lower stall speed and refusing to stall is doing something like that?.
If it provides upwards lift at low speeds/high AOA  it commands a pitch down plus it reduces a tiny bit of load from the front wing.Maybe enough to make a noticeable difference?.

But it does not fit very well at all with the other tail being faster and more glidey.Duh.

Maybe,as Jondrums wrote,you are just feeling the better pitch stability and dampened reactions that bigger tails provide.

 


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