Loos & Co. tension guides Inter20

I am looking for guidelines in the Loose & Co. measured tension setting on my diamond stays on Inter20 alu mast. I have now set to 35 (= average wind settings?) that I got from the tuning guide.

More wind, more tension, and if so how much more would I use?
Is there some sort of reference table around?

Additional setting: (We weight 160 kg (= 353lbs?), I have spreader set to approx 4.5 cm). Still figuring mast rake, bridle - half way rudder?


Any help, experience, links to info etc. is appreciated

Tx all!

I think your charting fairly new territory here with the aluminum rig. Please keep us updated on your findings.
Wish I could help.

We have some well documented numbers for the Carbon stick. But the alum one is, like Tawd says - uncharted territory for us all.

Didn't the guys in Singapore document some wingmast settings on a blog? Seems like it had posts abt cats, motorcycles and all kinds of stuff..... the author used to be fairly active here.... am I making this $%#@ up?

Scott McCook. I'll see if I can dig up his blog address.

Here's his blog but I don't know if there's any tuning info present on it.

https://boatsbikesboards.wordpress.com/

You're thinking of DucatiScott - http://www.catsailor.com/forums/ubbthreads.php?ubb=userposts&id=4559

He has a couple of blogs -
http://boatsbikesboards.wordpress.com/
http://prosailing.wordpress.com/

I THINK, the best starting point is going to be to hoist the main and get the mast curve to fit the luff of the main through a combination of diamond wire tension and spreader rake. Are you running a double spreader rig with single or double diamond wires?

Most of the N20 tuning guides are for the carbon mast; we don't go much above 42 on the Loos gauge on the carbon mast. I'm not saying the aluminum will bust when you go higher than this, but for right now (until someone who's done it chimes in), I would stay below this value.

Ahh ... I stand corrected. Apologize or the rabbit trail.

TVS gets mentioned here

I sure wish you guys would boil down your tension readings to lbs using the table on the gauge. It would make the "brand / type" of gauge a non-issue (at least within the accuracy of the gauge).

Amen. There's at least 3 or 4 different gauges. Even ones of the same model vary.

You shouldn't need to go as high with the alluminum mast since it will bend somewhat easier than the carbon, depending on your spreader rake.

You could talk to Mark Smith, since he has spent some time tuning the rig, and could probably get you in the ball park . . .

I agree and I apologize for using the spring scale numbers instead of the conversion to lbs...my scale happens to be 2 hours away so this makes things a little difficult. Also, arguably a bigger problem is the variance between one scale and another OF THE SAME TYPE. This problem is so bad the Olympic sailors use 3 Loos Gauges and average them; then they all wised up and bought a more accurate and precise digital scale, at the tune of $300+.

Best bet is to talk to someone whose done it before, which is no one in this thread to MY KNOWLEDGE. Another good starting point is an infusion sailor since they use the same mast section AFAIK.

Along these notes, we seriously need a good tuning guide for the N20. Of the three I've seen, only the factory one is concise but it is very conservative and all of them are several years old. Maybe nothings really changed, but I'm sure there are better methods to obtaining a fast boat.

@all: tx for reactions and info.

fwiw:

I have been sailing in Aruba (Carribean) we had 32knots wind, and used 41 on scale Loose & Co. (the expensive one with the two weels - sorry no conversion lbs at the moment. That number was advised by Sander Pols who we sailed with. Sanders is a fine person (he sails really well, and is very friendly). He is involved with Nacra Europe as one of the owners. As first timers on this Heineken regatta we were offered lots of help and advice.

(yes, that 32 knots was way to much for us, broke spipole twice, lots of other damage to ourselfe and gear ;-) and had the wildest ride of our lives. Never actually raised the spi. At least we had off-shore wind, or we would not have lived to tell ;-)) It was a learning experience, to put it mildly.

I guess I would start at 35 at 20knots, and work upwards in increments of 2, hoping not to reach 41 again.

>>I THINK, the best starting point is going to be to hoist the main and get the mast curve to fit the luff of the main through a combination of diamond wire tension and spreader rake. Are you running a double spreader rig with single or double diamond wires?

Yes, that is a good idea, will try that.
We are running a single spreader with single wires, like described in the Singapore threads offered by MikeMT (tx for those).

Tx for info on blogs, will start reading.

Mbalhizen... Are you talking about an infusion mast?
I'll tell you our range on our infusion is pretty much 37-42 and we've gone a bit higher when it really starts honking.
We usually sail around 39-40
Most of the other infusion sailors I know have a similar range and average.
I've never gone below 37 and don't know if I would.
With the new mast base it is essential to carry a wrench on the water so you can adjust per conditions on the water.

In case anyone is wondering how you do this, you set up the boat on shore (including correct stay tension for conditions and adjust the mast to various loos gauge settings, counting the quater turns on the nut as you go. Then when you are out on the water you keep a running count up and down on the nut as you adjust it between races to stay within the upper and lower limits. Like card counting - but easier...

Chris.

Hu? What about F18 class rule C.9.6:

Chris... making a scale with a reference point on the diamond wire is a bit easier. I use both where the end of the swage fitting comes out of the mast and a piece of tape around the diamond wire. I have small scales on each. I have 2 because above 40.5 the swage fitting goes into the mast and that becomes useless.
Pepin... that means while racing, you do this between races.

Yes Pepin technically you are correct, but the new rules weren't released to us until two days ago (Tuesday). In Chris's defense the old rule had the 'while racing' verbiage.

And while we are on the subject and before you drop some coin on the new Velocitek devices you probably want to look at rule C.5.1.b.3

2010 F18 Rules

So what does that mean now that it doesn't have the while racing wording?

I have always wondered about this when people are talking about doing that. Wouldn't you want the curve of the luff to match the curve of the mast only when max downhaul is on? Theoretically, the sail matching the curve of the mast would make the sail as flat as possible, right?

I've fired off a request for clarification along with several other questions to the international committee.

Technically, but the way I understand it is you want the mast to be set up to match the sail such that as you increase down haul, the wrinkles in the luff come out evenly. Spreader rake has effect on this as well. I've also READ that the Tornado and 49er guys don't change this setting much if at all on the same mainsail. I also know our boat was equally fast with a setting of 41 over an 8 month period and many regattas, ranging from super light air to 20-25kts. We are still looking for the mythical 6th gear, but I think its going to come from better driving, mast rake and tension adjustments, foil perfection etc., not from diamond wire tension.

So the F18's are banning GPS's (SEND or RECEIVE) except in distance events, yet requiring a magnetic steering compass? I can see the $100 bills in the TackTic executive pockets growing larger by the sentence...

You can buy a magnetic compass at walmart for less than $5.

I'm aware, I've probably bought 3 or 4 in my days of orienteering. I also don't consider those steering compasses...sure they'll tell you where north is but unless you mount it properly its a bad joke.

All I'm getting out of these absurd rulings is a ban on GPS, and thus a ban on Velocitek or similar devices.

Sam,
You type more words without stating anything new than anyone I've ever seen on here before. You deserve an award, I'll get on that. The annual Chronic keyboard diarrhea award. Done

Fixed it.