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Melges 24 turnbuckles and tuning

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I am new to Melges 24 and reading through the tuning guides I see the instructions for rig tension and changes based on wind speed.  I found one guild that mentioned the # of turns for the wind range changes were for Ronstan Calibrated turnbuckles and tuners should use 1/2 turns if they have normal open turnbuckles.  I don't see this in any other tuning guides, I have the open turnbuckles on my boat, should I be using 1/2 turns?

Should I be using any specific tuning guide or should I only be using the guide for the sails that came with the boat from the specific sailmaker?

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If you have the newer style turnbuckles then use half turns. 

We have found the north guide to be a pretty good starting point. 

Get your rake set right and make sure the mast is straight. Once your rake is right it is easy to ensure that the rig stays properly tuned with a loos gauge. 

The goal is to keep a little bit of slack in the leeward shrouds and lowers while sailing upwind. 

When it get's really windy and you have so much backstay on that the main is just folding in half and inverting upwind, that is a sign that you need more lowers. 

Top teams are putting on as many as 40 half turns on the caps when the breeze is on. 

 

 

 

 

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If the guide you are looking at maxes out at something like 20-24 full turns, its written for open turnbuckles.  If it maxes out at something like 40+ full turns, its written for Ronstan calibrated - you can then translate accordingly.

I'd start with the guide written for the sails you are using, or if you are really just starting out, whichever guide makes the most sense to you (or, as ASP says, North aint bad).

One of the best pieces of advice we got when first starting out was "If you can't get the boat to sail flat by adjusting the main controls & backstay, go up another step regardless of the wind-speed."  And the reciprocal: "if you are not depowering at all with main controls & backstay and you're pulling people off the rail, go down a step).

Otherwise its easy to get caught up in "but thats what the guide says for 15 kts" and sail around on your ear.  As you get better at depowering without rig tension, this rule of thumb still works.

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Not to highjack the thread but have a related question. Been out enough times where the wind has exceeded my expectations and the Main sail inverts quite a bit going up wind. Is that typically a sign that all shrouds need to be tighter or just the lowers?  On the fly, is  cranking the backstay, then the Cunningham and Vang the solution?

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Idk about 20 full  turns on the open body. That's a lot.  The north guide has 20 turns on the calibrated turnbuckles, which is 10 full turns on the open body. 

 

We stick to the north guide, we like the lowers pretty soft with north at base, but at 12knots tws we add another turn on the lowers.  For reference our boat will hold tensions on the loos B gauge at 17-19 knot setting (+10  and 7.5 turns), uppers 28.5 and lowers at 27. When we back down to base we get 16 on upper and some where between 3-4 fingers on lowers.   

The keys are to carry enough rig tension to hold headway sag when breeze on, and enough lowers to keep main pulling when back stay is on.  

 

 

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12 hours ago, Brent Cummings said:

Not to highjack the thread but have a related question. Been out enough times where the wind has exceeded my expectations and the Main sail inverts quite a bit going up wind. Is that typically a sign that all shrouds need to be tighter or just the lowers?  On the fly, is  cranking the backstay, then the Cunningham and Vang the solution?

if you crank the backstay on and the main folds in half, put on more lowers until you can reach max backstay without breaking the main in half. 

Lot's of teams have special stiff battens for heavy air as well. Helps put the main to sleep in 18+

 

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Irish - woops - yes, I turned it around - you are correct.  Something like 10+ turns is all the way up with open-body turnbuckles.  Our modified guide (based on Ullman) maxes out at 13.5 turns both upper and lowers.  See attached.

Capture.PNG

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backing off 6 full turns from base in light air seems bold...

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Try it next time you are in a "struggling to keep 2 kts of boat speed" situation - we spend a lot of time at the bottom end of the scale at home and works for us.

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2 hours ago, tanzer1645 said:

Try it next time you are in a "struggling to keep 2 kts of boat speed" situation - we spend a lot of time at the bottom end of the scale at home and works for us.

We call that the Seattle setting.  

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On 6/12/2018 at 4:53 PM, Irish River said:

Idk about 20 full  turns on the open body. That's a lot.  The north guide has 20 turns on the calibrated turnbuckles, which is 10 full turns on the open body. 

 

We stick to the north guide, we like the lowers pretty soft with north at base, but at 12knots tws we add another turn on the lowers.  For reference our boat will hold tensions on the loos B gauge at 17-19 knot setting (+10  and 7.5 turns), uppers 28.5 and lowers at 27. When we back down to base we get 16 on upper and some where between 3-4 fingers on lowers.   

The keys are to carry enough rig tension to hold headway sag when breeze on, and enough lowers to keep main pulling when back stay is on.  

 

 

Couple of comments on the thread:

 

First.  Different tuning guides have different wind conditions for “base”.  So just keep that in mind.  I would also recommend you use the guide, as a starting point, for the sails you are using.  If you have North and use the Ullman guide your going to be off.

With open TB and North we have put upwards of 22 turns on.  When we had Quantum I believe we had put 24....FULL TURNS.  It’s super fast BTW....

 

If your main rags or inverts; more lowers and then you can put more back stay.  We sail with a TON of backstay almost all the time.  When I max it out or are close we go up a step or even two depending on the conditions.  

 

Most people in my opinion are afraid to put turns on the rig.  The top boats go quickly on their steps and hard on their controls.  Keeping the boat at an average of 12 degree up wind or less in breeze you will rock.

 

Travis Weisleder

USA Class Prez

Lucky Dog

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8 hours ago, danberezin said:

Travis, interesting comment. I am wondering if your jib furler still works well under such load. 

Why would it need to? Jib stays out downwind..

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Replace your bearings.   Top and bottom. If you want to get crazy, but ceramic bearings in.

We will try adding more turns too. We do well, but are always looking for a 4th mode.

 

 

Can 591

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Setting the base setting for the lowers still has me miffed. Im new to the boat so be gentle. Ive read a couple threads somewhere where you tension them to 15 on the PT 10 and then back off 15 full turns for the Ronstan turnbuckles. So when I do this the stays seem very loose. Like flop around loose. Does this sound right. The other method they suggest is to go sailing and sight up the mast and look for 3/4 inch of mast sag. I dont know what kind of eye sight combined with coordination you all have, but to sight up the mast while sailing and sight 3/4" of bend in the mast seems a bit hokey to me. How is everyone else getting base setting for the lowers?

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Brent - looking for the sag is the only way I know to be accurate.  The tension up then down thing may get you close-ish but I do not think is reliable.  To help with the sighting here is our method:

1) put small red dots on the underside of the spreaders .75 in from the mast - then when sighting the mast, you basically line up this dot with the top and the bottom of the mast (i.e.: mast base, spreader dot, mast tip form straight line)

2) sight the mast in base conditions, crew in upwind mode, and someone steering on the wind (basically, full upwind mode)

3)  put your head at deck level with your eye right next to the front of the mast (i basically lay down on deck) - this gives a better perspective then trying to crane your neck back while squatting at the mast

4) when sighting, while laying on your back, grab the windward inner and pull it till the mast is straight, then let it off to see the curve, if you do this repeatedly (pull till straight, let off to see curve, repeat), you can get a much better feel for how much sag there is.

Once you get used to this the whole process will take you 60 sec. including the tack to check the other side.

Finally, since this has to be done in base-ish conditions, the classic problem is that you take your boat somewhere and its blowing stink when you are rigging so you do not have an opportunity to check sag.  The solution is to get your shroud measurements with a caliper at home in perfect base conditions, so you can go straight to that setting at a regatta.

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Yes, you could call it "very loose" depending on what your base of comparison is, but if you got to that by using the wind-up-then-down method, I'd bet you $50 its way off of where it should be - at least based on my results with that method.

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26 minutes ago, tanzer1645 said:

Yes, you could call it "very loose" depending on what your base of comparison is, but if you got to that by using the wind-up-then-down method, I'd bet you $50 its way off of where it should be - at least based on my results with that method.

Guess Chris Rast is wrong then

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6 minutes ago, ASP said:

Guess Chris Rast is wrong then

No, I think he's probably spot-on and the method is perfectly sound, I've just never been able to use it, then go out on the water and see it anywhere close to right (not for lack of trying).  I've also seen others struggle with this method w/o results.  One of those things where I'm sure I'm just doing it wrong, but can't figure out where my mistake is.

I guess the real point I'm trying to make is that the "sighting the mast" method works for a lot of people and should not be thought of as hokey.  If you are new to the class its just probably not something you've seen in a lot of other boat's tuning guides (at least it was for me).

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