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Spinnaker Sheets

PostPosted: Mon Aug 29, 2011 12:01 am
by jray
Ok, what I thought was a great idea for running the spinnaker sheets was less then what I had hoped for. Way to much going on in the back of the cockpit. It's time to figure out a better way. I'm looking for new ideas. :?

BTW The spin ride was awesome! :o

Re: Spinnaker Sheets

PostPosted: Mon Aug 29, 2011 4:55 am
by micah202
...beutiful boat you've got!
...I was out on Ben's build,Carbon Offset today.
...the spinn sheets run from the chute to the back corner then forward to a flush-deck ratchet maybe a foot behind the cabin--seems t'work well!

Re: Spinnaker Sheets

PostPosted: Mon Aug 29, 2011 2:13 pm
by jray
That's what I'm thinking of doing, maybe not quite that far forward, somewhere six inches or so in front of the traveler controls. Another project for this winter.

Re: Spinnaker Sheets

PostPosted: Mon Aug 29, 2011 4:14 pm
by micah202
jray wrote:That's what I'm thinking of doing, maybe not quite that far forward, somewhere six inches or so in front of the traveler controls. Another project for this winter.

of course,everything's a trade-off,,,,that position would be good for sheethandler to stand by the shrouds in lightair,,,
,,,,but would cross the crew

Re: Spinnaker Sheets

PostPosted: Tue Aug 30, 2011 3:24 pm
by Kevin
My spin sheets turn at the transom and are led up to the middle of the cockpit. Basically it's 1 butt forward of the frame 169. I also have my jib sheets led aft to the same area so there is only one place for the infamous butt cleat to mess up an otherwise nice gybe or tack. So far it's worked out ok. I'm probably going to swap the ratchet blocks to the transom so the sheet will more fully engage the ratchet (that hasn't been an issue yet, but the kite has only been up in the light stuff).
As for where to be in the light stuff, forward and flat is best imho. And there is debate on which way to heel, I think to weather to project the kite out a little more. And best to favor one chine in general I think.

Kevin.

Re: Spinnaker Sheets

PostPosted: Thu Sep 01, 2011 11:38 am
by jray
I've definitely got some changes to work on in the off season. Thanks everyone for the input, there's only two more weekends for racing, for now we'll make due with how it's set up. Until next year I'm using a small spinnaker, less then 30 m2 which makes handling sets and jibes much easier.

Re: Spinnaker Sheets

PostPosted: Mon Sep 12, 2011 5:28 pm
by micah202
jray wrote: Until next year I'm using a small spinnaker, less then 30 m2 which makes handling sets and jibes much easier.


....sounds like a good plan....I'm looking forward to sailing with -anything- not oversize!
...at the moment I've got the melges20 chute in the loft,getting cut to size,,,,,and my spare is an old 49er chute,,also 3-4' long on the luff
......it's tough sailing with oversize chutes,,,and pretty tough to sail much above dead-downwind.

Re: Spinnaker Sheets

PostPosted: Mon Sep 12, 2011 11:25 pm
by jray
Since then I visited with the former owner Josh. He told me that it's a 20 m2 he used for heavy wind. It's the perfect size to train new crew, not big enough for light air days though. ;)

Re: Spinnaker Sheets

PostPosted: Tue Sep 13, 2011 12:08 am
by micah202
heh,the old 49er chute's 37sq.meters!,with 3-4' extra luff length,,no wonder I can't reach!!!

Re: Spinnaker Sheets

PostPosted: Tue Sep 13, 2011 5:09 pm
by Kevin
That M20 chute definitely has too much luff length. My math says about 3 feet to much. Something in the 30' ball park should be good. That's viper chute size for those that might find one available. I saw Ron's M20 chute last year and the conditions were so light that the luff had a huge curve just above the tack to leeward instead of projecting out to windward. I had the opposite problem of a too short luff.
Kevin.

Re: Spinnaker Sheets

PostPosted: Wed Sep 14, 2011 6:46 am
by Big_Dog
Using the ISP & JSP, the straight line luff of the i550 is 29.2 feet. I do not have the rig dimensions for the Melges 20…. yet, but the spinnaker is 430 Sq ft. The luff on the Viper 640 comes in short at only 27.1 feet, but it the shoot is listed at 425 sq ft. Based on luff, the u20 is closest with a measurement of 30.4 feet; however the published data has the kite at 452 sq ft.

What length of lines and size are the splashed i500 using for spinnaker sheet(s)?

Re: Spinnaker Sheets

PostPosted: Wed Sep 14, 2011 9:35 am
by Shazza 273
8mm and about 20 or 25 meters from vague memory on Shazza

Re: Spinnaker Sheets

PostPosted: Wed Sep 14, 2011 12:37 pm
by jray
6mm or 1/4" flight line, total length for both sheets I think was 90' which gave me a little extra which is good as I'm rerouting the sheets and blocks this winter.

Re: Spinnaker Sheets

PostPosted: Wed Sep 14, 2011 3:27 pm
by Kevin
Big_Dog wrote:Using the ISP & JSP, the straight line luff of the i550 is 29.2 feet. I do not have the rig dimensions for the Melges 20…. yet, but the spinnaker is 430 Sq ft. The luff on the Viper 640 comes in short at only 27.1 feet, but it the shoot is listed at 425 sq ft. Based on luff, the u20 is closest with a measurement of 30.4 feet; however the published data has the kite at 452 sq ft.

What length of lines and size are the splashed i500 using for spinnaker sheet(s)?


My spin sheets are 8mm. My brother handed down some maffoli swift to me which is pretty cool stuff. It's spliced to 6mm spectra (which is overkill). I like the feel of a 8mm sheet in general but it's not needed for strength reasons and my sheets are all tapered. My spin sheets are too long still so I can't comment on length.

On the spin luff length, Big_Dog, I think your numbers are not exactly accurate. I have a viper kite and the luff on the kite I have is longer than 27.1 feet. The M20 kites follow the class rules maximum which is 34ish feet (I didn't bother to go look it up the exact number but I think it's 10000mm). Keep in mind that kite area can be manipulated in many ways. My i550 kite that's too short in the luff is much larger in area than the viper's 425 sqft class maximum.

I have real measurements off my boat at home if anyone wants to compare notes.

Kevin.

Re: Spinnaker Sheets

PostPosted: Fri Sep 16, 2011 8:06 am
by Big_Dog
The dimensions given are a straight line from the tack point on the pole (JSP) to the halyard exit (ISP). Since there is more data available on the rig dimensions and some class sail dimensions (none on an i550), it is a quickly way to see if you have a chance of using a sail. On the Viper this dimension is 25 3/4" short than the i550. If you hoist it all the way the shape of the luff and sail are changed. It may sail better at a high angle, but may not perform as well at say 135 degs off the wind.

The other number that would be helpful is the angle. In the case of the Viper the tack on the i550 is closer to the mast and the sail is raised higher. This higher angle (rotated more upright) the sheeting point moves aft to maintain the same sheeting angle.

That said, I would still picking up a Viper kite if the price is right. However I would also talk to your favorite loft(s) about re-cutting and other options available. Taking an old sail and manipulating it is an art. Taking a flat piece of cloth and sewing it into a shape that gets you to the finish line faster is way we pay them so much.

Re: Spinnaker Sheets

PostPosted: Mon Dec 12, 2011 1:18 pm
by jray
A question was brought up on another thread, thought I would move it here.

Launching the kite. Outside the side stays or inside? We have been launching inside between the stays and mast. If we are not tight at the mark we extend the prod earlier before reaching the mark and then run the tack out. Everythinglays on the deck. Normally set for a starboard set, it works great to jibe the mark and then set. When all goes well its great and when it doesn't, well you know. My question is how are others handling this evolution?

Re: Spinnaker Sheets

PostPosted: Mon Dec 12, 2011 6:13 pm
by Kevin
I launch behind the shrouds and under the boom. I have a bag that I made for the companionway that holds the kite. Launch is something like this (depending on crew numbers with 3 being ideal for a fast set). Pole and tack or separate lines so you can deploy the pole early if desired. Crew 1 on the spin halyard, Crew 2 on pole out and tack. Round the mark, Grab some kite and pull from the bag to get it loosened up, haul the spin halyard as fast as possible. Kite is behind the main. Pole out as soon as hoist starts with tack line un-cleated, haul the tack line when the spin is 2/3's up. This is pretty much a one-two punch as we are only going up a 25' mast. If all goes well the helm heats it up as the trimmer grabs on the sheet after the head and tack are hoisted at about the same time. You can preset the tack line if it's marked but you have to tend the foot of the spin along the leeward side. I only a crew of 2 then the helm can pole out and haul the tack and presetting the tack being preferred because he only has to haul one line.

I do a windward douse at the moment. The lines just need to be released and run free (assuming the lines have been tidied up after the hoist). Haul the lazy sheet to pull the clew around to windward, blow the tack line and pole out, gather the foot and make the first shove with the clew and tack together, blow the halyard and haul in the kite.

Well, that's how it's supposed to go :-). K.

Re: Spinnaker Sheets

PostPosted: Tue Dec 13, 2011 8:22 am
by Shazza 273
Kevin wrote:I launch behind the shrouds and under the boom. I have a bag that I made for the companionway that holds the kite. Launch is something like this (depending on crew numbers with 3 being ideal for a fast set). Pole and tack or separate lines so you can deploy the pole early if desired. Crew 1 on the spin halyard, Crew 2 on pole out and tack. Round the mark, Grab some kite and pull from the bag to get it loosened up, haul the spin halyard as fast as possible. Kite is behind the main. Pole out as soon as hoist starts with tack line un-cleated, haul the tack line when the spin is 2/3's up. This is pretty much a one-two punch as we are only going up a 25' mast. If all goes well the helm heats it up as the trimmer grabs on the sheet after the head and tack are hoisted at about the same time. You can preset the tack line if it's marked but you have to tend the foot of the spin along the leeward side. I only a crew of 2 then the helm can pole out and haul the tack and presetting the tack being preferred because he only has to haul one line.

I do a windward douse at the moment. The lines just need to be released and run free (assuming the lines have been tidied up after the hoist). Haul the lazy sheet to pull the clew around to windward, blow the tack line and pole out, gather the foot and make the first shove with the clew and tack together, blow the halyard and haul in the kite.

Well, that's how it's supposed to go :-). K.


Same on Shazza, except we drop to leeward at the moment which is slow but effective every time. (been wondering why we don't drop to windward though lately)

Re: Spinnaker Sheets

PostPosted: Tue Dec 13, 2011 5:29 pm
by Kevin
Oh, one more thought to remember, Make sure you are going over your jib sheets and not under them. Not a issue for me with my deck layout the way it is. But I once had that issue on a open 5.70. The jib sheet has to be held in front of the kite bag so the kite goes over the sheets. If you don't then you have to hoist under the jib (assuming you take the mark to port) which is a pita and hard on the spinnaker too.
Kevin.

Re: Spinnaker Sheets

PostPosted: Wed Dec 14, 2011 2:56 am
by jray
Thanks Kevin and Josh, we will try some of this next spring. We are alwase two up and how we have been handling the launch and retrieval has been working though busy for one person. We have been retrieving down wind just before turning the bottom mark, using the main to shadow the spinnaker bringing the clew in using the lazy sheet and blowing the halyard, once all is down, tack in then pole in. Just reverse of how we have been launching. Seems we might be doing everything backwards, time to try other methods. :shock:

New spinnaker on order for next season. I still will use the pink and green for those special times but am looking forward to 10 m2 more for the other times.