Need help for SPI setup.

Perhaps this works better for you guy's

Sorry

Meter Foot
9,63 31,59 Mast length.
8,08 26,51 Spi
9,34 30,64 Spi
4,2 13,78 Spi
25 82,02 Square foot Spi

LOL, meters,whats that??? Well the the safe place for the spin. hound is believed to be one third up,the distance between the main hound and top of the mast. I'm not sure where the stock spin. hound is on a N boat. Most seem to be half way. What boat did the spin. come from. Can you go back to that boat and measure those dimensions? I would opt for the lower spin. hound postion and if needed have the spin. recut.

Mike

The height of the spin tack-pole height, has alot to do with it.

If you're tramp launching it, put the tack lower, rake the mast back, that equals a lower hound height.

Todd and Mike,

I've became intrigued by another thread recently showing spi setups on international Tornados.

What are your thoughts on this type of attachment?

There is a hound mounted on the mast by the previuos owner, and indeed it is mounted app one third from the main hound.
When I look at other 6.0's they alway's mount between top and hound app 1/3 from the top.
I am thinking of lounching from the tramp.
The length of the Spi pole will be app 12.8 foot (3.9 meter)
And yes Kevin I am thinking of a similar hound, there is also a lot of info on this on Wouters site.
Does anyone have used a set up like this ?

I use a setup similar to the one in the picture for my Prindle 19, and it works great. I recommend it highly; you only have the one (or two) holes in the mast itself. The bail (or leash, or tether) that holds the halyard to the mast is drilled thru the luff track and does not compromise the watertighness of the mast. Further, it minimizes weight aloft, and promotes mast rotation. All good!

sail fast

I agree, have same on my Spitfire, and also had on my Hawk, allows mast to rotate fully.

I dont see that the bail, lash/tether goes into the luff track. How does it work? Does it tie thru 2 holes, have eyes on one or each side?

Thanks,
David
SEACATS

From Wouter's pages: You can see the two holes into the luff track. Knot is on outside.

Kevin, My set up is some thing like the one pictured.The only diffrence is my spin haylard is led inside the luff track. It goes over the top of the mast through two small blocks and then down to the hound block. The nice thing is I only have one line hanging around if the chute is bagged and no line against the outside of the mast. You need to keep an eye on the hound line. If you can't run it like mine then it has to be done like the picture.

Mike

As far as the pole goes,how much adjustment do have with a N boat. Does the foil restrict you?

Mike

Try the site:
http://www.geocities.com/f16hpclass/Tech_genaker_mast_setups.html

The foil does limit how high you can bring the pole. Many of the 6.0na sailors use bridle foil wires that are 4" longer than stock. (I just ordered a pair from Rick Bliss at New England Catamarans.)

Dermot,The only problem with that setup is it looks like there is 4 holes instead of just two. Am I seeing that right?

Mike

We have the same method of having a strop at the height of the required position of the pulley, if you want to have fewer holes in the mast, take the line to the top of the mast & tie it off there instead of drilling 2 holes in the sealed part of the mast for an eyelet. (See the attached pic.) The holes for the line which holds the pulley in place are in the luff track, outside of the sealed section of the mast, so no water can get into the mast.

Cheers
Steve

Wouters photo has 4 holes in the track, where the rope goes in and then out again on the same side and is knotted.
The photo that Kevin has at the beginning of this thread, looks as if the hole is just large enough to take the rope twice. It goes across the track, out, and is then knotted.
As others have said, holes in the track do not compromise the sealed mast.

I understand the holes don't enter the sealed part of the mast. My point is if two work why drill more.

Off to Miami,
Have Fun
Mike

Kevin, et.al.,

I have been posting a link to the tornado site for awhile now. MIne is rigged exactly like the pic, and my knots for the bail loop line are INSIDE my sail track. It works fine with just two holes, pull it thru, tie a knot, and slip it back into the sail track, the outside knot obviously works also.

For those who don't have the link:

http://www.acay.com.au/~bundy/layout.html

This is a good discussion, enjoy!

Quote

I have been posting a link to the tornado site for awhile now. MIne is rigged exactly like the pic, and my knots for the bail loop line are INSIDE my sail track. It works fine with just two holes, pull it thru, tie a knot, and slip it back into the sail track, the outside knot obviously works also. . . This is a good discussion, enjoy!

Todd,

Links to sites like that are sooooo helpful. Thanks. The photographs of the rigging details are great. One thing that I noted was the hardware used for attachment to the main beam. Any thoughts on the best way to source those specialty items?

On a related note, aside from old windsurfer masts, etc., it seems that there's always difficulty in sourcing aluminum tubing for poles. Yesterday I was poking around in the Thomas Register for distributors. When looking at the various specs for t-6061 drawn tubing, this question came to mind. What is the minimum acceptable wall thickness? (Say, for a 2" OD tube.)

Also, for those who run the tack line inside the pole, what do you use for blocks where the line exits near the beam? Is it an in-line, through deck block set into the pole?

Anything above 1.6 mm should be fine. = 1/15 th of an inch

1.8 mm would be prefect = 1/14 of an inch

But 2.0 mm (2/25 of an inch) is most available for tubes of the outer diameter your looking for and will work well to. Don't go for 3 mm as that is only heavy and your than better of with a larger diameter 2 mm tube. Stiffer, lighter, and stronger.

Wouter

Wouter,

Thanks for the feedback. Since my boat is still in winter storage, I pulled the 2" OD number off the top of my head. The tube I've got now is probably closer to 1.5", though. Smaller diameter tube would necessitate a thicker wall, right?

The reason I'm asking is because I came across a source for 6061 tubing, but they have only 0.55" or 0.125. Sounds like the one would be too thin, and the other would be too thick. Ideally, I'd like to find something in the .07 - .08 range.

>>>Smaller diameter tube would necessitate a thicker wall, right?

Yes, but it is a very bad relationship. Always go for bigger diameter than bigger wall thickness. The larger diameter tube is always lighter for the same given stiffness.

Indeed .07 and .08 " are good wall thicknesses as long as you mian diameter is at least 1.5" or bigger.

If you get 0.07 by 1.5 than you'll have to support it in the middle to prevent buckling but on a N6.0 you can tie th pole to the foil and solve that little issue that way.

Good luck.

An inch = 25,2 mm

Again Ideal pole will be 40 mm by 2 mm tube. Or get very close to this one.

If you can't find that

go for 35 mm by 2.5 mm or 3 mm and support that in the middle !

If you can't find that than look harder.

If you find something and you're not sure wether it will work than contact me and will do the math.

Wouter