49er rigging problem

feffe

New member
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There is probably a 5% chance that tweaking luff line tension will rectify the issue, again it's a 10 year old spinnaker, regardless its worth the try.
Thanks @JulianB for the good advice as always. I'll make a try next days! I also have a pretty good spinnaker from 2019 still never used by me, I can try it to clear my doubts.

And what about the lenght of the spinnaker pole? I can quickly modify it tweaking an eye splice and it can change a lot. Is there a reference measure?

 
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JulianB

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Sydney mostly
Mast rake is defined by a class rule, so I can comment on that.

Pole lenght is not, so I can't comment on that.

But I would suggest you allow your pole to extend as far as you can without doing some dumb rigging idea to over extend it.   It will be limited by the hole the pole extension line is terminated in, that can't go past the alloy collar/guide, so that is your maximum extension.

Under extending the pole will roll the luff out, so it becomes flatter, allows you to go higher, yes it's a bit "nervous" but you are compensating that by the sheeting angle becoming more vertical so that gives you greater control over the leach.

Over extending the pole (which you basically can't do) rolls the luff up, makes it more bull nose, and in lighter air, that will get you lower soon but you quickly get to the point where you over run the spinnaker, and that aint pretty. 

 

JulianB

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short answer is no.

But as I did sail those rigs, I know that Forestay went up to 34 even 36 in a breeze, some went as far as 42, think the max I went was 37-38 but it had to be blowing oyster of the rocks to get to that.

Caps went to 21, some took it higher but I thought that was pointless.

D1's where simply set to get the right lower mast bend.

 
short answer is no.

But as I did sail those rigs, I know that Forestay went up to 34 even 36 in a breeze, some went as far as 42, think the max I went was 37-38 but it had to be blowing oyster of the rocks to get to that.

Caps went to 21, some took it higher but I thought that was pointless.

D1's where simply set to get the right lower mast bend.
Ok thanks, No clue what caps are but im sure i'll figure it out.

Thanks your a legend

 

allweather

Member
400
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baltic
No clue what caps are but im sure i'll figure it out.
Cap shrouds are the ones going to the top of the mast. Then you have main ones running through the spreaders and the lowers(sometimes diagonals I think).

Also, you did have a look at the old "49er owner's manual?" http://www.49er.org.uk/cms/upload_area/downloads/49er-owner-manual.pdf
They have a basic setup for the rig...

Really wished that the class association published something similar for the new masts and generally updated setup. Knew more than one guy that struggled with setting up an older boat when they didn't have personal contact to the race circuit. Sure, they(old guys often enough) won't go for any medals, but still sometimes feels like a missed second hand market opportunity...

 
Cap shrouds are the ones going to the top of the mast. Then you have main ones running through the spreaders and the lowers(sometimes diagonals I think).

Also, you did have a look at the old "49er owner's manual?" http://www.49er.org.uk/cms/upload_area/downloads/49er-owner-manual.pdf
They have a basic setup for the rig...

Really wished that the class association published something similar for the new masts and generally updated setup. Knew more than one guy that struggled with setting up an older boat when they didn't have personal contact to the race circuit. Sure, they(old guys often enough) won't go for any medals, but still sometimes feels like a missed second hand market opportunity...
Thanks, yeah i did but as i mentioned it only covered a very specific wind speed for the setup.

 

feffe

New member
18
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Mast rake is defined by a class rule, so I can comment on that.
Is this the only driving rule for the mast rake?

[SIZE=20.2655px]C.9.3 DIMENSIONS [/SIZE]
[SIZE=18.7644px](a) The forestay[/SIZE] length is controlled by laying the forestay along the forward
[SIZE=18.7644px]face of the [/SIZE][SIZE=18.7644px]mast spar[/SIZE][SIZE=18.7644px] and measuring the extension of the forestay[/SIZE] beyond
[SIZE=18.7644px]the mast heel. This distance shall be taken between the forward extension of [/SIZE]
[SIZE=18.7644px]the bottom of heel tenon and the bearing surface of the forestay[/SIZE] pin and shall
[SIZE=18.7644px]be minimum 425mm and maximum 435mm. [/SIZE]

Under extending the pole will roll the luff out, so it becomes flatter, allows you to go higher, yes it's a bit "nervous" but you are compensating that by the sheeting angle becoming more vertical so that gives you greater control over the leach.

Over extending the pole (which you basically can't do) rolls the luff up, makes it more bull nose, and in lighter air, that will get you lower soon but you quickly get to the point where you over run the spinnaker, and that aint pretty. 
Got these tips! I will try tuning it during the next water session (no wind so far)!

 

JulianB

Super Anarchist
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Sydney mostly
Feffe, +/-5mm, you x by approx 5 to get the movment at the hounds.

So basically you move the hounds +/-25mm.

Let me just clarify a few things re wires and placxments because names change across the world.

First you have the "D" system.   D = Diagonals.

D1's are the first set of "diagonal" wires as you go up the mast, D2's are the 2nd and D3's the 3rd.

Then you have Lowers, Shrouds, and Caps, Shrouds resolve somewhere near the forstay, and are sometimes also the Caps (confusing)

The Hound is where the Forestay meets the mast.

OK, Lowers = D1's, that's simple, in the case of a 49er, Shrouds = D2's and they resolve (come into the mast) at the hounds as dose the forestay.

Caps = D3's and they "cap the mast" which is where there name came from.

OK, back to Feffe, moving the hounds +/-25mm will move the CoE +/-15mm and given the CoE is trailed (behind) the CLR

 https://9eronline.com/library/49er working sail dynamics.jpg

113mm then 15mm is quite a bit, so it will alter your feel and your balance.

If you are starting out, then I would recomend that you have it as short as you can, and BTW, you can make the forestay from Synthetic's and that in turn allows you to make this adjustable, via a sliding splice.   M4 of even SK78 has a BS of 2000kgs (2 tone) where as M3 wire has a BS of 1 tone, so just season the wire and you wont have a issue.

The reason you have it short is it makes the boat far more forgiving coming out of a tack.

Re Rake and keeping the nose out, downhill,  that if far more governed by the Caps/D3's, so what would end up happening is they would be, instead of say 19 (long f/stay), you would have them at 20 (short f/stay).

(Some would say that rake fwd (short f/stay) = nose diving, and that is partially true, but extra tension in the caps overcomes that)

~~~~~~~~~~~~~~~~~~~~~~~

In 2 hrs time I will be in the estemed company of Emmett, Euan and Malchom looking at the (hopefully) final version of the 3Di sails, and I will attemp to again get some pearls of wisdom (re tensions) from them to grace these pages.

ciao, jB

 

JulianB

Super Anarchist
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1,304
Sydney mostly
Ok, I'm getting a list of setting for the old alloy mast and the SS mast of Emmett.  We joked about the old mast and people chasing quite modest tensions and the boat simply bending. He gut WRT the alloy mast was 26 in very low, under 8knts.   27-28 is a far more "reasonable " number, up to 33, you just about never go over 33-34.

Biggest thing out of today, is it highly likely you will bend the boat more than you bend the mast.    Let you know when I get the list.

         jB

 

feffe

New member
18
1
OK, back to Feffe, moving the hounds +/-25mm will move the CoE +/-15mm and given the CoE is trailed (behind) the CLR

 https://9eronline.com/library/49er working sail dynamics.jpg

113mm then 15mm is quite a bit, so it will alter your feel and your balance.

If you are starting out, then I would recomend that you have it as short as you can, and BTW, you can make the forestay from Synthetic's and that in turn allows you to make this adjustable, via a sliding splice.   M4 of even SK78 has a BS of 2000kgs (2 tone) where as M3 wire has a BS of 1 tone, so just season the wire and you wont have a issue.

The reason you have it short is it makes the boat far more forgiving coming out of a tack.

Re Rake and keeping the nose out, downhill,  that if far more governed by the Caps/D3's, so what would end up happening is they would be, instead of say 19 (long f/stay), you would have them at 20 (short f/stay).

(Some would say that rake fwd (short f/stay) = nose diving, and that is partially true, but extra tension in the caps overcomes that)
Thanks @JulianB for share these infos! Really helpfull as always. I will try the dyneema forestay if I find a fitting for the mast.

Hope to get a satisfying rig setting next weekend!

Federico

 
Hi Federico,

I use 616506f from Bluewave, should be available online from most countries within EU.
6165xxF_web-2-ox4sqhzc00gufyv1h6x9ogwocjx1wa3dwj8b3gpa2o.jpg


https://bluewave.dk/products/small-t-rope-eye/

I will try the dyneema forestay if I find a fitting for the mast.

 
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