Finn rigging

WCB

Super Anarchist
4,394
857
Park City, UT
When that boat was built you weren’t permitted to have a range of adjustment. But the pivot bolt location and range are the Sam e, so I suspect it’s fine. The tolerance was millimeters, not centimeters.  So a range of 3/8”.  New rigs with stiffer masts probably have a placement different than the Needlespar set up.

SHC
I read the modifications done to the 1976 Vanguard from the link the Craigslist thread. The author mentioned that change and it was the first that I heard of it.  He also modified the boat for carbon masts, that makes more sense now.  Just lots of curiosity on my part.

 

BIYC

New member
10
4
So Cal
Steve,

Peter Harken brought one of the first Vanguard Finns to the Newport Beach boat show in 1975, he said a big effort was made to achieve minimum Lamboley numbers on that boat. By spring 1976 at Nationals half the fleet and the winner were sailing Vanguards. Just wondering if they were able to hold that tight tolerance as production ramped up. 

BIYC

 

surf nazi

Super Anarchist
What's the story with the centerboard being able to move fore/aft?  How much travel does it actually have?  I set up a friend with a '91 Vanguard to race next weekend at the PCCs and I doubt that the centerboard can move though I can't say for sure. How does one measure for such a thing?  Meaning, do we measure from the transom corner to the trailing edge of the centerboard when fully down when the boat is on its side?  
Max travel allowed for centerboard under rules is 2 cm about 3/4 of an inch. Max aft is 2050 mm from bottom of transom to aft edge of centerboard. Depends on weight, stiffness of boat, wind speed and sea state as to where you want the centerboard. Basically aft is depowered and forward is powered up. 

 

WCB

Super Anarchist
4,394
857
Park City, UT
Max travel allowed for centerboard under rules is 2 cm about 3/4 of an inch. Max aft is 2050 mm from bottom of transom to aft edge of centerboard. Depends on weight, stiffness of boat, wind speed and sea state as to where you want the centerboard. Basically aft is depowered and forward is powered up. 
Thanks so much, @surf nazi It will be interesting to measure where it's at.  Is anybody measuring boats at the PCCs?

 

Steve Clark

Super Anarchist
Surf Nazi:

+/- 10mm is bigger than I recall, but not an unusually large tolerance in the world of measured one designs.  In fact =/-10 is the usual tolerance. It unusual to find tighter tolerances.  This is the design space people use to develop faster models within a one design class rule.    Vanguard Finns were right on the tolerance at a few places. Notably high in the bow they were as narrow and low as possible and still be a Finn. There are standard tolerance tweaks that happen in all one design classes, low and narrow above the waterline forward is #1.  A long diatribe on how not MOD racing classes are measured could follow.  It is arcane knowledge, but it is amusing. 

Almost all Finns were 10 kg ( maximum correctors) light.  We didn't place the correctors until we were actually doing the Lamboley.  The way to get a quick visual is by looking at the relative placement o the inspection port in the double bottom.  We were also very concerned about keeping the Longitudinal Center of Gravity as far aft as possible. There definitely was a range where most of our boats fell.  The only thing I recall being further from optimal than the others was the CG height.  and I couldn't determine if this was good or bad.  Ultimately we were building boat for customers and didn't mess around trying to find the perfect Finn. There are multiple variables, I don't have the records, but I recall there was a pretty close grouping of the results. It is hard to say what was just right because it depended on a particular sailors felt was good and not on any scientific basis.   Measuring the pitch frequency of the hull is only part of the total problem.  Changing the mast ( different weight different height cg)has a huge effect on how the boat pitches. Rake also effects the rig CG and thus how the boat pitches.   No one ever paid us to test complete rigged boats, which is what you would have to do to really understand what was going on.

When we built the fleet for Barcelona, we were more preoccupied by being consistent and making sure there wasn't a lemon in the bunch. Our QC has the exact weight of resin for each and every operation and I'm pretty sure the whole fleet was within a Kg of itself and didn't vary more than 5 mm.

SHC 

 

Steve Clark

Super Anarchist
Yes you want bungees to hold the centerboard down.  When you turn turtle the need will be readily apparent.

I think in this case the orange bungee goes around the front of the trunk and repeats what it does on this side.

SHC

 
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Bungees on either side of c/b case?   How are these attached & are they needed?  
 
Kevin

This is how it's set up on the Devoti's: blocks on the side of the centerboard trunk, bungee goes around the front and back through the block and hooks onto the crossbolt. You might have a 2:1 setup, if you go around and hook it back to itself

FinnCBBungee.png

 

BIYC

New member
10
4
So Cal
Surf Nazi:

+/- 10mm is bigger than I recall, but not an unusually large tolerance in the world of measured one designs.  In fact =/-10 is the usual tolerance. It unusual to find tighter tolerances.  This is the design space people use to develop faster models within a one design class rule.    Vanguard Finns were right on the tolerance at a few places. Notably high in the bow they were as narrow and low as possible and still be a Finn. There are standard tolerance tweaks that happen in all one design classes, low and narrow above the waterline forward is #1.  A long diatribe on how not MOD racing classes are measured could follow.  It is arcane knowledge, but it is amusing. 

Almost all Finns were 10 kg ( maximum correctors) light.  We didn't place the correctors until we were actually doing the Lamboley.  The way to get a quick visual is by looking at the relative placement o the inspection port in the double bottom.  We were also very concerned about keeping the Longitudinal Center of Gravity as far aft as possible. There definitely was a range where most of our boats fell.  The only thing I recall being further from optimal than the others was the CG height.  and I couldn't determine if this was good or bad.  Ultimately we were building boat for customers and didn't mess around trying to find the perfect Finn. There are multiple variables, I don't have the records, but I recall there was a pretty close grouping of the results. It is hard to say what was just right because it depended on a particular sailors felt was good and not on any scientific basis.   Measuring the pitch frequency of the hull is only part of the total problem.  Changing the mast ( different weight different height cg)has a huge effect on how the boat pitches. Rake also effects the rig CG and thus how the boat pitches.   No one ever paid us to test complete rigged boats, which is what you would have to do to really understand what was going on.

When we built the fleet for Barcelona, we were more preoccupied by being consistent and making sure there wasn't a lemon in the bunch. Our QC has the exact weight of resin for each and every operation and I'm pretty sure the whole fleet was within a Kg of itself and didn't vary more than 5 mm.

SHC 
Great insight from Steve Clark

 

blunderfull

Super Anarchist
Kevin

This is how it's set up on the Devoti's: blocks on the side of the centerboard trunk, bungee goes around the front and back through the block and hooks onto the crossbolt. You might have a 2:1 setup, if you go around and hook it back to itself

View attachment 390832
Yes, it’s funky looking but not wanting to leave my c/b off Pt Loma, I’ll wrangle it a bit .

BTW:  Thks Dino for the F’book drawings.   That’s pretty much how this Newport is rigged.

 

Dino

Anarchist
820
17
Ireland
Here’s my old Pearson Finn project. I think she’s a 1960’s boat. It was in Ireland since new as far as I know. Sail number IR10. 
It came with an old wooden mast.

I’m looking for a Needlespar mast and boom and a sail if anyone in Ireland or the UK is selling one. 
I’ve started to strip the boat back and I’ve done some sanding. 

F74A4E67-4A28-4E26-96A1-5A4CF3A02008.jpeg

F02FDFEA-773E-4E8D-9E73-4AF21D77F903.jpeg

29EDB527-D789-40EC-B197-558281838A96.jpeg

 
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Here’s my old Pearson Finn project. I think she’s a 1960’s boat. It was in Ireland since new as far as I know. Sail number IR10. 
It came with an old wooden mast.

I’m looking for a Needlespar mast and boom and a sail if anyone in Ireland or the UK is selling one. 
Ask Rodney Cobb at Suntouched or look on the Finn Buy/Sell/Charter Facebook Page

 

WCB

Super Anarchist
4,394
857
Park City, UT
Anyone talked to Mike D about Friday nite trailer drop-off in yard?   Apparently not w/o SDYC permission according to RN.   
I emailed Mike D last week about the delivery of the boat for my friend, Ryan, who is sailing it.  It comes in tomorrow and he said no problem.  There's also mention on the PCC registration that there is storage on site until the 16th.

 

surf nazi

Super Anarchist
Surf Nazi:

+/- 10mm is bigger than I recall, but not an unusually large tolerance in the world of measured one designs.  In fact =/-10 is the usual tolerance. It unusual to find tighter tolerances.  This is the design space people use to develop faster models within a one design class rule.    Vanguard Finns were right on the tolerance at a few places. Notably high in the bow they were as narrow and low as possible and still be a Finn. There are standard tolerance tweaks that happen in all one design classes, low and narrow above the waterline forward is #1.  A long diatribe on how not MOD racing classes are measured could follow.  It is arcane knowledge, but it is amusing. 

Almost all Finns were 10 kg ( maximum correctors) light.  We didn't place the correctors until we were actually doing the Lamboley.  The way to get a quick visual is by looking at the relative placement o the inspection port in the double bottom.  We were also very concerned about keeping the Longitudinal Center of Gravity as far aft as possible. There definitely was a range where most of our boats fell.  The only thing I recall being further from optimal than the others was the CG height.  and I couldn't determine if this was good or bad.  Ultimately we were building boat for customers and didn't mess around trying to find the perfect Finn. There are multiple variables, I don't have the records, but I recall there was a pretty close grouping of the results. It is hard to say what was just right because it depended on a particular sailors felt was good and not on any scientific basis.   Measuring the pitch frequency of the hull is only part of the total problem.  Changing the mast ( different weight different height cg)has a huge effect on how the boat pitches. Rake also effects the rig CG and thus how the boat pitches.   No one ever paid us to test complete rigged boats, which is what you would have to do to really understand what was going on.

When we built the fleet for Barcelona, we were more preoccupied by being consistent and making sure there wasn't a lemon in the bunch. Our QC has the exact weight of resin for each and every operation and I'm pretty sure the whole fleet was within a Kg of itself and didn't vary more than 5 mm.

SHC 
Thanks for the knowledge. Very interesting. Max corrector weight is now only 5 kg. 

 

WCB

Super Anarchist
4,394
857
Park City, UT
@blunderfull look for this Finn at the event.  Skipper's name is Ryan.  The boat just arrived to SDYC and he'll be there working on it off and on over the next couple of days, maybe sailing Friday.

IMG_9408.JPG

 




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