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-   -   severne sails tack pully? (http://www.star-board-windsurfing.com/forum/showthread.php?t=619)

dave 5th November 2006 10:30 AM

severne sails tack pully?
 
I use a severne sail and have an issue with the built in tack pully. The three pully system on the sail does not perfectly match up to the pullys on my mast base, and the large size rollers on the sail have quite sharp edges. consequensly, when fully down hauled the rollers on the sail cut my down haul rope after about 4-5 times used. this is an extream pain in the u know what!!
has any one else had this problem as well, and what is the base pully system recomended by the sail designers??

thanks Dave
6.4m S2

Roger 5th November 2006 08:08 PM

RE: severne sails tack pully?
 
Hi Dave,
What mast base (brand....i.e. Chinook, HPL, Streamlined, North, NP)
are you using?
Are the pulleys in the sail and the pulleys on your mast base "oriented" the same way....i.e. do the pulleys on your Severne sail have the "axle" running across the board, or fore and aft, and which way is the "axle" oriented on your mast base?
How close do your sail tack pulleys and mast base pulleys come together when you have your sail fully downhauled?
Your issues could be due to how you are "threading" the pulleys, or how far away they are when your rig is fully tuned.
Also, what model is your Severne sail? I've been rigging some Gators,
and NCX's on HPL (Across the board) and Streamlined (fore and aft) with no problems.
Hope this helpps,

Roger 5th November 2006 08:20 PM

RE: severne sails tack pully?
 
Hi Dave,
Just saw down at the bottom near your name that you have a 6.4 m2
S2. Is that an '06 or'07 sail or older?

dave 6th November 2006 04:02 AM

RE: severne sails tack pully?
 
hi roger,
my mast base is a rdm carbon radz hawaii with the pull axel running across the board, the same way as the sail. the sail is a 06 model. the base pully system is however a 4 pully system, though I thread it to match the 3 pully sail block. I have done this in the past with other sail with out problems. though the severne is a different thing. personally I wish that sail makers wouldnt sew in all these different pullys as when you change sail brands you seem to have to change every thing else these days as well?

Roger 6th November 2006 09:26 AM

RE: severne sails tack pully?
 
Hi Dave,
I spent some time looking for a photo of the Radz Hawaii Carbon RDM extension so I could see the horizontal spacing between the tie off point on the LH side of the plastic base cup, and the horizontal spacing of the individual pulleys (sheaves actually) and then the horizontal distance to the cleat hole on the RH side.
Unfortunately Radz Hawaii.com says they are reworking the website so I couldn't get a look at your particular base.
What I do with a 4 pulley mast base is wrap the line from the tie off point on the LH side down and around the front of the LH most sheave so that the line leads up from the rear side of that pulley (with the axle side facing you).
This takes away the funny angle that the line must follow to go from the tie off point on the front LH side of the mast base up to the LH sheave (pulley) on the tack of the sail.
So, with the line leading up from the back side (the side that faces back toward the clew of the sail) of that first pulley, there is much less "angularity" between the mast base pulley and the tack pulley in the sail.
Then the line goes up and through the LH tack sheave from back to front, then down to the middle pulley on the base from front to back,
then up through the larger dia. center tack sheave from back to front,
then down through the RH sheave on the base from front to back, then up and through the RH sheave on the tack pulley from back to front and down to the cleat.
On some bases, you get a bit of extra angularity out to the cleat, but I think it's better if any angularity ends up on one side vs pulling the tack cleat hard from both sides which can create the situation you seem to have where the line is getting "cut" by the edges of the sheave.
Another option here is to tie a large stopper knot in the ends opf your line and simply put the line down behind the LH most pulley in the base and forget about the tie off point which is sometimes well off to the LH side and forward.
Also, what size line are you using?
Most WS bases use pretty small line so it sits well down in the sheaves.
If you line is a bit larger, you increase the potential for cutting the "cover" on the braided line.
If you coulod send me a small digital photo of the pulley and cleat arrangement on you Radz Hawaii (to my email address or as a Private message here on the forums, it would be great to confirm what I'm suggesting above. It wouldn't be necessary if the Radz Hawaill site was working so I could see one of your type mast base extensions.
Hope this helps,

DannyL 7th November 2006 07:28 PM

RE: severne sails tack pully?
 
I have the same with my Severne sails.(ncx,overdrive,c2)
I am using a NP extension.
Before I was using NP sails it this was more easy to 'line the line'

when I set it like recommended and have to pull it the whole way down it comes out of line...the lines are struggling

for me it would be much better if Severne turns the tack pully 90 degrees.Same position than the gaastra and NP.

Greetings,
Danny

Roger 7th November 2006 08:17 PM

RE: severne sails tack pully?
 
Hi Danny L,
There a 2 solutions here that I know of.
The first is a "total solution" but it requires buying a new mast base.
Get a genuine "Streamlined" mast bast (they can be purchased in reg. dia. and skinny as both Chinook and Euro Pin tops) with the "Quick 6"
fore and aft oriented sheave and cleat assembly.
Everything lines up perfectly so no more problems.
The 2nd solution should work with your NP base, and it's really pretty easy.
Bring the line up from the tie off point and run it from left to right over the front most sheave on the tack pulley assembly.
Then run it back down to the RH pulley on the mast base and thread it around this sheave from the front to the back (away from the center of the mast base).
Then thrread it up and over the farthest back (away from the centerline of the mast base) sheave on the tack pulley assembly from the RH side to the LH side.
Now thread it under the LH most sheave in the mast base from the back of the sheave to the front of the sheave.
Then back up to the tack pulley and over the center sheave from the LH side toward the RH side. Make sure you don't get the lines "crossed" here. It's the only place where you need to watch for this.
Then run the line down to the cleat on the RH side.
If your downhaul line is long enough, you should have not problems getiing all the "threading" done with little or no tension on the line.
Then pull the tension on slowly, check that none of the lines have jumped out of their sheaves and it should be quite easy to downhaul your sail with no damage to the line at all.
Hope this helps,

Then down to the

Roger 7th November 2006 08:58 PM

RE: severne sails tack pully?
 
Hi Danny L,
Guess I should not try to answer forum technical questions before my first cup of coffee in the morning.
I'm going to leave what I wrote above, but for your Severne sails, with the pulley that runs across the sail (vice fore and aft like the NP, Gaastra, Sailworks, and Windwings) it's incorrect.
The NP base that I have would seem to work perfectly with an across the rig tack pulley.
The recommended Streamlined "Quick 6" base pulley and cleat system works better with fore and aft aligned tack pulley sheaves.
Where ever possible try to get the mast base pulley system that avoids the "crossed axis" situation.
Then you can simply start at one side and "wrap" the line in each sheave progressively "across" the axle from the tie off point across to the cleat and everything lines up. If you have a 3 sheave tack pulley and a 4 sheave base pulley/cleat assembly, run the line from the tie off point under the first sheave on the LH side of the base so there is less "spreading" force on the tack pulley and the sheaves all line up better both at the top and the bottom.
So, for your NP base (which one....how many sheaves..?) start at the tie off point and run the line up and over the LH sheave in the tack block from the front to the back.
Then run the line down and under the LH most sheave in the mast base from the back to the front.
Then run the line up and over the middle tack pulley from front to back.
Then down and under the RH pulley in your base, from back to front, then up and over the last RH sheave in the tack block from front to back and then down to the cleat.
With parallel axis pulley "axles" you simply wrap your lines "across" the sheaves, starting at one side finishing up in the cleat on the other side.
Sorry for the confusion! :(

steveC 8th November 2006 12:04 AM

RE: severne sails tack pully?
 
Hi Roger,

I have been using Bill Hansen's sails (Windwings) for over 20 years, and he started using a sewn-in 3 position fairlead in the early 90s and changed more recently to a 3 sheave/pulley design. While I matched the sails up with Fiberspar mast extensions, I believe they are the same in concept as the NPs. The combination yields sail and base axes at 90 degrees to each other. I should point out that I always rig with the starboard side of the sail up, so this must be kept in mind when following the instruction below.

To successfully thread the line and avoid any crossed lines, there is only one way I found that allows a virtual mating of the sail to the base. Starting with the tie off point you thread the line up and over the sail sheave closest to the mast and down and through the top of the base sheave closest to the cleat. The line should then be run up and over the frontside of the sail sheave farthest from the mast so the line comes down and enters the base sheave closest to the tie off point from the bottom. The line then comes up and runs through the middle sail sheave from the underside so that the line ultimately comes down and threads through the cleat. The secret is that the line is worked around the sheaves in opposing directions.

More recently I bought another brand mast base that included the Streamline "Quick 6" pulley system where, as you pointed out above, the sail and base axes align. Unknowingly, I tried the opposing threading method I had been using for years. Big mistake. While I ultimately figured out the proper method, I still fought with it a number of times before getting the picture.


Roger 8th November 2006 03:22 AM

RE: severne sails tack pully?
 
Hi Steve C,
Yes, when the axis of the upper and lower "axles" are the same, it's pretty easy to thread a downhaul line. Just think of a large industrial crane. The vast majority of them simply thread the wire rope around the sheaves starting at one side and working toward the other and the upper and lower sheave are on axles that are the same axis (across the front of the crane).
So, I can see, after years of doing it the NP/Bill Hansen way (I never could figure out those diagrams very well) changing to the "Quick 6" with the upper and lower axles running fore and aft could be a challenge until you figure out that it's a simple "start at the sheave nearest the mast, on both upper and lower sheaves and simply wind the line around them like they were one large diameter tube.
I use alot of both types of bases, but my sails are all Sailworks with a fore/aft tack block, so I get to rig a few of each type of base at demos. I got to rig the new Severne 7.5 m2 "Glide" this morning on a NP base and an HPL base so I'd remember how to use parallel axles that run across the board (just like the crane).
Keeps me on my toes!


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