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Spin trim help

Posted By: jody

Spin trim help - 03/22/11 01:20 PM

Joanna and I have noticed that since we have been running the goodall spin that we seem to have a very fine area where it is flying and that it seems to need to be tight most of the time. Does any one have a suggestion of any adjustments we can look at making to let it fill out some more or is this what others are finding with this spin?

thanks
Posted By: Gilo

Re: Spin trim help - 03/23/11 09:11 PM

Jody,

Do you have this feeling at every windspeed?
I had the same feeling with the landenberger spi at a very wide windrange. It also meant I had to steer higher downwind then the average cat on the race track.
2 most important things to know here is if your luff tensions is ok for that spin (too much and it might be too full toward the middle, or vice versa) and what the ideal sheeting angle is (this might differ between the Blade and viper for which the spin was made).

With the Glaser spin now used on the Falcon it is totally
different. You easily feel the sweet spot. You can easily let it out, with the result that you have massive power and steer quite deep.

Gill
Posted By: PTP

Re: Spin trim help - 03/23/11 10:21 PM

I made the mistake recently of messing with the luff line in the tape of my spin last week. Changed things some maybe not for the better since it seemed not to have much of a range. IMO one needs a PhD in spinology to really determine what the correct luff tension is for the boat, spin, and sailing style.
Posted By: Joanna

Re: Spin trim help - 03/24/11 12:54 AM

Gill-
I have issues at all the wind speeds. Feel like I have to pull it in very tight to keep it flying correctly. Have checked luff, seemed fine, but will do that again. The Glaser spin seemed to have a much larger "range", or easier to keep flying. Will also check the sheeting angles next time we are out. I noticed the difference btw the two from the start.
Posted By: PTP

Re: Spin trim help - 03/24/11 01:12 AM

What is the correct sheeting angle? 1/3 from tack? Whatever gives best shape? What is the best shape?
Posted By: Anonymous

Re: Spin trim help - 03/24/11 04:48 AM

you should play with the sheeting angle in the smae way you do with a jib. ie fwd to flatten the top of the sail and/or add shape down low or aft to add shape up high or flatten down low. put some wools on your kite it will make all the difference.
Posted By: Joanna

Re: Spin trim help - 03/24/11 10:33 AM

"wools" is that the same as "tell tails"?
Posted By: Cab

Re: Spin trim help - 03/24/11 12:11 PM

Joanna,
I think the luff on the Goodall spin is a little shorter, 6-8 inches. I remember that you guys moved the block on your mast down when you made the change. I moved the pole a little higher because I was sailing uni and not using the pelican striker. Mine seems to work fine, the same as the Glaser. The vipers carry their spin pole higher than the blades. Maybe that has shifted your sheeting angle a little?
Posted By: jody

Re: Spin trim help - 03/24/11 12:43 PM

So by lowering the spin we would have to move the sheeting angle forward I guess? Is there any special backing for the spin blocks if I move them forward?
I do think you are probably right one that Chris since we moved the Goodall job tack up a few inches the boat seems to be pointing and performing better. Also makes more sense on the lower part of the jib near the foot of the main where more power can be used (I think that is right).
So to move the spin pole up some I assume we need a shorter pelican striker?
Posted By: Chris9

Re: Spin trim help - 03/24/11 12:55 PM

Maybe before drilling holes in things try heasing the haylard off some or maybe a lot...
Posted By: pgp

Re: Spin trim help - 03/24/11 01:01 PM

Originally Posted by Joanna
"wools" is that the same as "tell tails"?


Some peope HATE tell tales on their spinnakers.

My first spinnaker came without tell tales, the second with. It's the difference between night and day for me, I have to have them.

Posted By: mikeborden

Re: Spin trim help - 03/24/11 01:03 PM

Have you measured the distance of the end of your spin pole to the top where the spin hoists to?

Here's what I have been told to do....

Measure the head of the spin to the tack. When you get that measurement, then add 1% to it. That should be your measurement from the end of your spin pole to the point where it hoists to.

Mike
Posted By: Cab

Re: Spin trim help - 03/24/11 01:14 PM

Jody,
An easy test would be to put the spin block back in the original place on the mast, raise the spin pole using a piece of line instead of the pelican striker, go out without the jib and see if the spin does better. If it does, I think it would be easy to make a pelican striker that is a few inches shorter.
Posted By: Timbo

Re: Spin trim help - 03/24/11 02:38 PM

When you are sailing downwind, are you always trying to be on one hull? I always want to be on one hull unless it will lead to a swim.

I have 2 spins. A very "full" cut spin and a very flat one. I've found it's easier for me to fly a hull using the very flat one, I can head up, get the hull up, accelerate and ride it downwind on one hull much easier than with the very full cut spin, which doesn't want to go high enough to get the hull up in medium air.

In heavier air, I run deep on two hulls usually (when running on one will most likely result in a pitch-pole) so the fuller cut spin is better for that.

It is a little counter-intuitive, you would think the flater spin would be better (de-powered) in bigger winds but actually it's better in lighter air as you must head up higher to get the hull up. The fuller spin is better for running deep on two hulls in big air.
Posted By: jody

Re: Spin trim help - 03/24/11 02:41 PM

Tim who made each spin?
Posted By: Timbo

Re: Spin trim help - 03/24/11 02:56 PM

The fuller one is an older Glaser, from about 4 (?) years ago. The flatter one is about 1yr. old Landenberger.

The fuller one is easier to keep from stalling, but as I said before, you can't go as high with it to get the hull up in light/medium wind, where as the Landy is much easier to "heat it up" and get going after the set, get a hull up and get cruising. But when it's really blowing, I don't sail on one hull.


The times I've tried to go on one hull in big wind, I seem to stuff it to the mast too often, which really slows you down, even if you don't go swimming. I've found it's more 'productive' to sail it deep on two hulls and jump over the waves rather than plow through them on one hull and stuff it to the mast.

But in medium wind I want to be on one hull all the time, upwind and down, so the flatter spin works better for that.
Posted By: jody

Re: Spin trim help - 03/24/11 04:01 PM

how tight are you running the flatter spin on the sheets.
Posted By: Matt M

Re: Spin trim help - 03/24/11 04:41 PM

Originally Posted by jody
how tight are you running the flatter spin on the sheets.


This should not matter. The sail should fly within a broad range of sheet tension settings.
Rig the sail with the luff tension “in the ball park” 45-90 degrees with a fist twist. Then sail it.
You can try different sheeting angles to see then if that is the issue or the sail is just a bad cut. If it is relatively light have the crew below and hold the sheets simulating more forward or a more aft sheet location. Forward will pull the leach and aft will pull the foot more. If it is windy it is easy to rig a quick moveable sheet point much like the old barberhauler system on my H20.

The F16 has a max hoist height and a max spin pole length, so the potential combination of triangles for the sail are pretty limited. The Viper has a higher set pole but on the Blade if you jack up the pole the jib is also moved, so watch out screwing up that sail trim in the process. I would not go drilling new holes or cutting strikers off until you know that this is the fix that will actually work.
Posted By: Timbo

Re: Spin trim help - 03/24/11 04:43 PM

Pretty tight at times, maximum in, but that's only when I'm really trying to get as high as possible, usually when the wind is on the lighter side. Normally I'm easing and trimming continually trying to keep the luff on the edge of curling.

Also counter intuitive; easing the halyard will actually make the luff a little flatter so you can point a little higher, and pulling the halyard tighter will put more of a curl into the luff, which is ok when running deep in big air, but not what you want for pointing in light air.
Posted By: Timbo

Re: Spin trim help - 03/24/11 04:49 PM

Now Jody, if you would hurry up and get down here, we could get out and practice all this stuff on days like today!

Supposed to be 88 today, 92 by Sunday, and it's blowing 13 G 25 out back right now. I'm going on a bike ride now but when I get back, I'm going sailing.



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Posted By: Gilo

Re: Spin trim help - 03/24/11 05:35 PM

You should never sheet in hard on the spin (unless you are reaching). It should always be sheeted so it doesn't fall in, even in heavy air, you will notice a huge difference in sheeting out that last inch.
Maybe your main is not sheeted correctly to your spin. Personally I use tell tales a the leech of the sail top 3 battens. I let out the main untill those are flying (this will seem quite far out, but works ok for me (mast will look quite bendy). This will generate more power and lift in the main and might work better for the spi too.
Also talk as skipper to your crew when heading up or bearing away, and crew should inform the skipper how the spin feels.
Finally go your own course. If your spin isn't made to sail high and fast don't do it, because it will not work.

Just sold a new Glaser spin to one of the Blades here, I'll let you know my experience.

Gill
Posted By: Joanna

Re: Spin trim help - 03/24/11 07:45 PM

" Now Jody, if you would hurry up and get down here, we could get out and practice all this stuff on days like today!"

Don't tempt him!!!! Can't believe he is breaking up a great team and leaving me here!!
Posted By: Timbo

Re: Spin trim help - 03/24/11 07:47 PM

You should come on down too Joanna, plenty of room, plenty of sun, plenty of water for all!
Posted By: Anonymous

Re: Spin trim help - 03/24/11 09:21 PM

Question for Matt...

Have you ever considered, or been asked to put a short track on the hulls to allow tweeking of the kite sheet leads?
Posted By: Joanna

Re: Spin trim help - 03/24/11 10:44 PM

Tim-Will consider it, but HAVE to have jobs first! Plus it is hard to beat working only Tues-Thur.
Posted By: Matt M

Re: Spin trim help - 03/25/11 12:44 PM

Originally Posted by Scarecrow
Question for Matt...

Have you ever considered, or been asked to put a short track on the hulls to allow tweeking of the kite sheet leads?


I rigged up the barber hauler set up several times as we worked to develop the spin for my boat. It would be an easy enough installation to mount a short section of jib track to the hull if you really wanted. I am not sure why you would want anything “mounted” permanent. There is way more than enough going on with lines and such on the boat now. The spin as I try to set it up is set and forget. All the way up and all the way out – then pull from 1 place smirk
A few boats have been supplied with multiple spin block attachment points. I found it does not matter except in the very lightest air – then the crew is low anyway and can pull directly on the clew.

For me the fewer adjustment I make is directly proportional to how fast I sail.
Posted By: Anonymous

Re: Spin trim help - 03/25/11 10:13 PM

I wasn't thinking of an actively adjusted track. More like a pin stop thing like they originally had on the hobie 18 for the jib. Theory being you could set it on the beach for the conditions and also adjust for different kites without playing with pole height etc.
Posted By: samc99us

Re: Spin trim help - 03/30/11 04:27 AM

Gill,

Any concerns about mast breakage when easing your main out a bit? I sailed the N20 like this in once race, previous owner saw the boat and commented that the main wasn't tight enough and your mast was bending all over the place. I took his advice as he is a far better sailor than I, but I felt the eased main was faster. During Tybee I dropped the traveler a lot and eased the main probably more than recommended, but this was typically only done when trying to out climb F18's or impending Jetty's.

I'm surprised at the variety of spinnaker cuts in this fleet, I think the F18's have all tended to a flatter cut at this point. I'm also surprised the issue of where to sheet the spinnaker hasn't come up before in other classes? Based on this information it sounds like buying the same sail as originally supplied with the boat is best to avoid drilling holes but maybe that sail shape isn't fastest.

Jody and Joanna, do you feel faster with the flatter spinnaker when its trimmed properly?
Posted By: mikeborden

Re: Spin trim help - 03/30/11 12:56 PM

What Gill is saying is just ease the Main enough to get the Tell tales to fly properly, which isn't much. The main will stall if you don't. It will help to drive the boat better.

Most of the masts that do break with the spin up are in the most extreme cases. For one instance, going downwind, stuff the hull, the main comes uncleated(eases out a LOT) and you stuff the hull. Another one is you capsize, and the spreaders aren't centered on the diamonds and then once you sheet hard going upwind the mast breaks. That situation is resolved by putting some epoxy about an inch above and below where the spreaders are connected to the diamonds.

Again, the most extreme cases....


Mike

Posted By: mikeborden

Re: Spin trim help - 03/30/11 12:58 PM

I forgot to mention,


The difference in the spins is just improvements that the sail makers do each year. It's that way with the mains too.

Posted By: pepin

Re: Spin trim help - 03/30/11 01:03 PM

On a calm day put your spi out and sheet it in all the way. Look at the sheet and the line it forms from the pulley to the clew. Basic measurement is to make sure this line crosses the luff at 90 degrees or so. It is usually better to have the pulley too far back than too far forward as you really don't want to close the gap between the spi and the main by pulling the clew down, so if in doubt, move it back.

When I changed spi from the original Stealth 'R' cut to the GP F16 one I had to change all the geometry of the front triangle: despite being the same size (17.5m2) the new spi is way flatter, with a longer luff and a clew set lower. I had to lengthen the pole by 40 cms and move the sheet pulley forward quite a bit to be able to get a good shape in it.
Posted By: pgp

Re: Spin trim help - 03/30/11 02:25 PM

Is the pole still legal in length?
Posted By: pepin

Re: Spin trim help - 03/30/11 02:42 PM

Yes, the original Stealth 'R' pole was short. The new one is right at the legal length.
Posted By: Gilo

Re: Spin trim help - 03/30/11 04:34 PM

Mike,

Indeed you need to ease just a bit. The Falcon spin is cut flatter then the original Blade one meaning it is easier to match your mainsail position to the angle of the wind (you sail higher and faster).

Just watch out if you start to head up with the main eased to make a mark for example. If you have the main eased and leave out the traveler a fair amount the mast becomes very bendy... :-)

Gill
Posted By: Tornado

Re: Spin trim help - 04/06/11 09:06 PM

Originally Posted by samc99us
Gill,

I'm surprised at the variety of spinnaker cuts in this fleet, I think the F18's have all tended to a flatter cut at this point. I'm also surprised the issue of where to sheet the spinnaker hasn't come up before in other classes?


Tornado's play with the sheet point quite bit. We typically attach the blocks to the tramp lacing points along the inner gunwales. I use a quick release Ronstan clip with lanyard on the pin. We move the blocks forward one position in light air when we can't fly the hull. Then back one posiition for moderate. Finally one or more back positions in the wild stuff.

I've always found this makes huge differences in spin power for the conditions.

When I used a new
spinny from the Canadian Olympic team for hte first time on my boat, I found it was very fussy...constantly collapsing even when sheets beyond what I like to have.
Here you can see the collapse:

[Linked Image]

And how it looked prior to collapse:

[Linked Image]

Sent these to the Olympic team I bought it from and the reply was "Luff WAY too tight"...despite using our normal "90 degree fist twist" setting. We had to let out 6-10 inches of halyard before the sail became fast and more stable.

We now have it about right and sail much lower and much faster than my local crowd of F18's in all conditions.
Posted By: JeffS

Re: Spin trim help - 04/07/11 09:50 AM

Fantastic info Mike, did they tell you how to recognise that the halyard needs to be let off?
Posted By: Tornado

Re: Spin trim help - 04/07/11 03:55 PM

Originally Posted by JeffS
Fantastic info Mike, did they tell you how to recognise that the halyard needs to be let off?

Unfortunately no...just that the pics looks way off from being right and our report of the sail collapsing every few moments/killing our race performance. The GranSegal older/more dialed in sail I put on for the second day of the same regatta got us right up challenging for the lead against the best I20 team in SoCal. We were back in 7th or 8th with the new kite the day prior.
since making the luff looser on the new sail, we are find it to be faster than the Gran.
Posted By: tshan

Re: Spin trim help - 04/07/11 06:45 PM

Does this matter?

Jody is using a Goodall spin on a Blade. The Viper (asuming the Goodall sail was made for the Viper) has its spin blocks on the inside edge of the hull. The Blade has the spin blocks mounted on the outside edge of the hull. Does that make any difference? Gotta be 10 to 12 inches differences there.

Have fun in Gulfport!!!
Posted By: Tornado

Re: Spin trim help - 04/07/11 10:10 PM

I'm sure it must matter how far inboard/outboard the spin sheet block is placed. On the T it is always at the tramp lacing points or directly to the inner gunwales. But, the T is a 10' wide boat. I believe I20's (8.5' beam) sheet from the outer gunwales.
In general terms, I would think anytime your creating an excessive curve of the clew inboard toward the sheet point, you're loosing performance (too much "belly" in the sail shape).
Posted By: Anonymous

Re: Spin trim help - 04/08/11 01:08 AM

That would make a huge difference and is probably the source of the issue. All the modern F18s sheet to the inside as well. As kites get flatter I wouldn't be surprised to see people sheeting off the tramp.
Posted By: jody

Re: Spin trim help - 04/08/11 01:48 AM

I think we are going to try the luff loosing first. Robbie had made mention I think at a clinc once it looked off and we messed with it some and it looked better but were afraid to play it much more. Is it better to let the halyard off some, the tack off or actually drop the hoist height some?
Posted By: Timbo

Re: Spin trim help - 04/08/11 02:33 AM

You forgot, "...or raise the pole tip." which would be my first choice to 'fix it'.

If you are already out on the water and it doesn't look right, easing the halyard off a few inches is the easiest thing to do, until you can get back to shore and raise the pole tip.
Posted By: Gilo

Re: Spin trim help - 04/08/11 06:06 AM

Make sure you have a fix setting that is good. In a race you don't have time to check if your halyard is ok. I let it of in races when there is very little wind and I mark it with a piece of tape in the halyard and the mast.

Gill
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