89er

WCB

Super Anarchist
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Park City, UT
Julian,

If you don't feel like sharing I can completely understand but I'm curious about what's going on with the 49er class that's leaving you in a position to lose money.  Shouldn't the class be completely self sufficient by now?

 

JulianB

Super Anarchist
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Sydney mostly
Julian,

If you don't feel like sharing I can completely understand but I'm curious about what's going on with the 49er class that's leaving you in a position to lose money.  Shouldn't the class be completely self sufficient by now?
It's my decision to "share the pain".     We put so much effort into actually reducing the cost of the mast and the bits on the mast, to "piss that up against the wall" because of a arcane spec change process really grates.   Then you have people like Tom yesterday who send emails that lift your spirts.   The nay-sayers are probably less than 10%, and to condem far more than the 50-60-70% who really appreciate what you have done and how hard you have tried is not fair on them.  

The only down side is you carry the nay-sayers, but at some stage they realise they are f--k-wits!

The wheel turns, it always has and it always will.

If you really want me to get DM re this conversation, let me have a few more reds, and I will come back to it, otherwise leave it at that.

 

WCB

Super Anarchist
4,258
778
Park City, UT
It's my decision to "share the pain".     We put so much effort into actually reducing the cost of the mast and the bits on the mast, to "piss that up against the wall" because of a arcane spec change process really grates.   Then you have people like Tom yesterday who send emails that lift your spirts.   The nay-sayers are probably less than 10%, and to condem far more than the 50-60-70% who really appreciate what you have done and how hard you have tried is not fair on them.  

The only down side is you carry the nay-sayers, but at some stage they realise they are f--k-wits!

The wheel turns, it always has and it always will.

If you really want me to get DM re this conversation, let me have a few more reds, and I will come back to it, otherwise leave it at that.
I see...makes more sense now.  I'm sure that you've spent enough time dealing with this that I don't need to make you relive it over a DM.  I've certainly experienced something similar.

 

G30ff0

New member
11
4
Sydney
Foil moulds in the front yard, the fun begins!

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Awesome thread/build blog, just stumbled onto it today, appreciate the time & effort you put into explaining everything. I have learnt a lot & binged the whole thread this arvo

Would you be prepared to share some of the art/science on the uni/fibre angles & placement so that the boards feather vs gybe. I ask as I am going to make some new foils shortly & just banged a lot of Carbon Uni down the centre between 2 layers of Dbl Bias without giving it much thought on my last set.

Thanks in advance 

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JulianB

Super Anarchist
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Sydney mostly
Awesome thread/build blog, just stumbled onto it today, appreciate the time & effort you put into explaining everything. I have learnt a lot & binged the whole thread this arvo

Would you be prepared to share some of the art/science on the uni/fibre angles & placement so that the boards feather vs gybe. I ask as I am going to make some new foils shortly & just banged a lot of Carbon Uni down the centre between 2 layers of Dbl Bias without giving it much thought on my last set.

Thanks in advance 

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Let me get back to you on that.   Crazy 1st half of the week, in fact all of the week is madness.

 

JulianB

Super Anarchist
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Let me get back to you on that.   Crazy 1st half of the week, in fact all of the week is madness.
It's wet, and I'm bored, so I will make a start.

Form the above pictures I take it that you are sucking laminate and foam into each 1/2 of the moulds, you then mill it flat and stick the 2  ½ves together?    Made a hell of a lot of 49er foils that way, but as the sailors evolved, they pushed harder and harder and we started getting sheer line happening in the glue joints so we had to find another way.

In the case of the 49er we now mill solid blocks of foam (H80) and generate what are known a “milled cores” which are accurate to about 0.75mm, so we now layup the moulds in exactly the same way, but one laminate is left over length, it stands out at the front (and bottom) by 20-30mm, the core is then bogged and laid into the side with the stand out, it (standout) is wrapped around the core (the LE) and then the other side is vacuum clamped down onto the core all become one mass.   One of the biggest advantages of the vacuum is it virtually eliminates any voids, and bubble that’s starts as say 2-3mm³ in size ends up humongous as the pressure gets close to zero, and it quickly exits the laminate.

The reason I have gone into that detail is because feathering (or gybing) foils do twist the foils and you need good integrity of the LE joint and voids rapidly become big issues.

Possibly the reason we had to go away from the 2 ½ves milled/sucked together model of production was because of the added twisting element that feathering foils generate.  

With a 49er, it’s pretty easy to make them feather, it’s a shortish foil, so very few other issue like oscillation/harmonic vibration even though it has the potential to go very quickly, we also alter the section shape to dampen that, doesn’t take a lot, but it works.   So the actual amount of Carbon Unie directional is quite small, because it’s small, it can/is [be] stacked and you have a lot of scope as to where to centre that stack.

image.png


So this is a rough approximation of a 49er C/Board section, red is the Lift vector, and blue is the structual vector based on the Carbon stack (black) being centered at max thickness.

image.png

All I have done here is move the whole stack fwd 20-25mm, you could also move the layer within the stack fwd or both, you can then "cut" the stack fwd.

image.png

Or you can angle (and cut) the stack fwd, almost no structual downside to either of these alingments, but huge increase in tip area mobility.

image.png

And yes these are 49er profil shape, but WRT the 49er, the size of the carbon makes it quite hard to do this, plus the way we designed the shape of the foil, we basically rendered feathering not worth the effort, and no, I won't tell you how we did that.

But in a conventional foil "dare I say that" these latter 2 examples are particularly relevant because it results in a very mobile aft lower area of the fin, so it will move alot.

WRT Don't Panic, the blub end plates the fin, so the need to feather is greatly diminished, all we really want to do is make sure it never tries to gybe.   A L bulb will just about always gybe, near impossible for it not to, so again with Don't Panic using a T bulb and a very well design T bulb [if I must say so myself] then the CoG of the bulb will be close to the LE of the foil, so our biggest concern is if we alow any sort of heel, that it dose no "over" feather!

But if we are heeling that amount, then feathering will be very positive.

Like anything in sailing, it's very easy to over cook it!

                            jB

 

allweather

Member
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baltic
And yes these are 49er profil shape, but WRT the 49er, the size of the carbon makes it quite hard to do this, plus the way we designed the shape of the foil, we basically rendered feathering not worth the effort
You know, I am here to watch the awesome boat take shape and see what new, cool methods you use, but you could just as well write a 49er blog and I'd read it all the time. Fair on trade secrets though.

It's not like I have expertise or am ever going to use it(probably), but darn if these insights aren't super interesting in addition to the normal build. Certainly widens the horizon.

 

G30ff0

New member
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Sydney
The reason I have gone into that detail is because feathering (or gybing) foils do twist the foils and you need good integrity of the LE joint and voids rapidly become big issues.
Thanks Julian,

Yes that is exactly how I made the foils, with the Uni centred on max beam with stacks running down to the tip using M80 corecell.

My set from the photo’s had the failure you mention in the quote above. I assumed it was 105kg’s of gorilla jumping on it.Though it may have also been compromised from the twist before hand along with possible voids & not paying as much attention to the process that I should have or some such combination.

Also as the chord is only 200 they are probably twisting more then I would have thought as well.

To try & address the sheer of the glue joint I was considering laying a piece if flash tape & a 20mm strip of peel ply along the LE for the top 400 mm or that way  I can tab the foils together once glued up.

Makes sense re moving the stack/angling the stack/feathering the stack.

My priorities were mostly on making sure it didn't Gybe rather then making it feather a lot. Being gorilla sized I am aiming for a stiffer board then most that feathers.

Thanks again for taking the time to answer a tangent

 
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JulianB

Super Anarchist
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1,410
Sydney mostly
Thanks Julian,

Yes that is exactly how I made the foils, with the Uni centred on max beam with stacks running down to the tip using M80 corecell.

My set from the photo’s had the failure you mention in the quote above. I assumed it was 105kg’s of gorilla jumping on it.Though it may have also been compromised from the twist before hand along with possible voids & not paying as much attention to the process that I should have or some such combination.

Also as the chord is only 200 they are probably twisting more then I would have thought as well.

To try & address the sheer of the glue joint I was considering laying a piece if flash tape & a 20mm strip of peel ply along the LE for the top 400 mm or that way  I can tab the foils together once glued up.

Makes sense re moving the stack/angling the stack/feathering the stack.

My priorities were mostly on making sure it didn't Gybe rather then making it feather a lot. Being gorilla sized I am aiming for a stiffer board then most that feathers.

Thanks again for taking the time to answer a tangent
So every 49er and 29er board (& rudder) gets tested before it gets it IHC (now MCE) plaque.

I have explained before how we get to the side load and from memory it's about 70kgs at the CLR of the fin.

To test them we developed a jig, and a procedure so a board tested in Australia roughly get the same result as one tested in the UK.    As part of that process, we also load up the board well past that 70kg load.    We apply something in excess of 100kgs at the tip.     In Milan on a few occasions we applied, as accurately as we could that 70kg load at the CLR which is only something like 350-380mm down from the keel and the movement of the tip was maybe 10mm.     Now a 49er board has a cord of around 325mm and a max thickness of 34mm so its a 10.25% section if people are at max tolerance.   My point being is that if we doubled the amount of Carbon Unie we may reduce the tip movement by 2mm, so from something around 10mm to something around 8mm, and for what, what is a stiffer board going to give you????

49ers go upwind at 7-12 knts.

A knot is 1.7ft/sec (that's a Dad-isum) so,  2 knts is almost exactly 1m/sec (bit of unit jumping).

So at 10knts = 5m/sec, you are doing a boat length a sec, approx.

But far more importantly you are doing 14-15 cord lengths/sec.

My point being 2mm of greater or lesser flex simply gets lost in the wake (excuse the intended pun)

Too late at night to do the maths but it's less than a minuet of angle (I think), so what’s the point, bigger fish to fry and to worry about something approach a minuet of angle.

Foil feathering is one of the tools that we use to a) reduces drag because it reduces the pressure differential as you approach the tip,  b) reduces the depth of the CLR which increases available power and it dose it at a rate that is commensurate with speed, therefor the board ability to carry that extra power and c) stops the board gybing which has various counter productive aspects inc vibration and oscillation.

~~~~~~~~~~~~~~~~~~~~~~

I was asked some months back to do a series of video’s explaining a 49er and to a far lesser extent the 29er and how they work.    The person asking me to do this is Ellen Jiao from Shanghai (OnePlus Boats) and backed up by people from across Asia, Myanmar, India & Arabia.

So I have spent some time trying to think what it is that’s different, after all, Asian have been making boats and doing huge mass migration while pre the Spartians.

Me being me, my mind races off into tangents, possible with Dad’s training/influence I have come to some interesting ideas, that I should share with you and you can peer review it.

Ciao guys, been a crazy day, may have been wet & bored but it also has been long!     jB

 

G30ff0

New member
11
4
Sydney
So every 49er and 29er board (& rudder) gets tested before it gets it IHC (now MCE) plaque.

I have explained before how we get to the side load and from memory it's about 70kgs at the CLR of the fin.

To test them we developed a jig, and a procedure so a board tested in Australia roughly get the same result as one tested in the UK.    As part of that process, we also load up the board well past that 70kg load.    We apply something in excess of 100kgs at the tip.     In Milan on a few occasions we applied, as accurately as we could that 70kg load at the CLR which is only something like 350-380mm down from the keel and the movement of the tip was maybe 10mm.     Now a 49er board has a cord of around 325mm and a max thickness of 34mm so its a 10.25% section if people are at max tolerance.   My point being is that if we doubled the amount of Carbon Unie we may reduce the tip movement by 2mm, so from something around 10mm to something around 8mm, and for what, what is a stiffer board going to give you????

49ers go upwind at 7-12 knts.

A knot is 1.7ft/sec (that's a Dad-isum) so,  2 knts is almost exactly 1m/sec (bit of unit jumping).

So at 10knts = 5m/sec, you are doing a boat length a sec, approx.

But far more importantly you are doing 14-15 cord lengths/sec.

My point being 2mm of greater or lesser flex simply gets lost in the wake (excuse the intended pun)

Too late at night to do the maths but it's less than a minuet of angle (I think), so what’s the point, bigger fish to fry and to worry about something approach a minuet of angle.

Foil feathering is one of the tools that we use to a) reduces drag because it reduces the pressure differential as you approach the tip,  b) reduces the depth of the CLR which increases available power and it dose it at a rate that is commensurate with speed, therefor the board ability to carry that extra power and c) stops the board gybing which has various counter productive aspects inc vibration and oscillation.

~~~~~~~~~~~~~~~~~~~~~~

I was asked some months back to do a series of video’s explaining a 49er and to a far lesser extent the 29er and how they work.    The person asking me to do this is Ellen Jiao from Shanghai (OnePlus Boats) and backed up by people from across Asia, Myanmar, India & Arabia.

So I have spent some time trying to think what it is that’s different, after all, Asian have been making boats and doing huge mass migration while pre the Spartians.

Me being me, my mind races off into tangents, possible with Dad’s training/influence I have come to some interesting ideas, that I should share with you and you can peer review it.

Ciao guys, been a crazy day, may have been wet & bored but it also has been long!     jB


The only reason I was looking at a stiffer board was over the years I had read/heard that stiffer was better for bigger sailors (I cant remember where I got it from) so more then happy to hear there is bigger fish to fry/I am over thinking it.

Appreciate your help & advice & I will lay up the next set as advised above!

 

JulianB

Super Anarchist
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Sydney mostly
The only reason I was looking at a stiffer board was over the years I had read/heard that stiffer was better for bigger sailors (I cant remember where I got it from) so more then happy to hear there is bigger fish to fry/I am over thinking it.

Appreciate your help & advice & I will lay up the next set as advised above!
I'm looking at a IC in the photo, is that the boat in queastion, or are you tooling around with something else??

 

G30ff0

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Sydney
I'm looking at a IC in the photo, is that the boat in queastion, or are you tooling around with something else??
The one in the photo is josie (Steve Clark) circa 2008 design.

 I have built a new IC, a Maas 5, designed by Chris Maas which is what the foils i am building are for.

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JulianB

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The one in the photo is josie (Steve Clark) circa 2008 design.

 I have built a new IC, a Maas 5, designed by Chris Maas which is what the foils i am building are for.

View attachment 509235

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Josie is possibly the boat I sailed in Ottowa with Steve and Dave, got to be back 2008-2012 ish time frame.

IC's have such a hi power to weight ratio, that they should need very little span (depth) because they are going to get up to a reasonable speed very quickly.

Probably the biggish issue you will have will be oscilation/vibration, so some off axis fibres would probably be a good thing.

 

G30ff0

New member
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Sydney
Josie is possibly the boat I sailed in Ottowa with Steve and Dave, got to be back 2008-2012 ish time frame.

IC's have such a hi power to weight ratio, that they should need very little span (depth) because they are going to get up to a reasonable speed very quickly.

Probably the biggish issue you will have will be oscilation/vibration, so some off axis fibres would probably be a good thing.
From memory Josie stayed in Aus post the dec 2008 worlds, though she was one of 3 ‘josie hulls’ from the same mould with one of the hulls being modified at some point. Possibly it could have been Wonk, Steve’s trial boat to the proposed rules was around still then, I am not sure what other boats Steve & Dave had at that time.

Occasionally I have heard some high pitched vibration/humming on the reaches at the higher end of speeds i have managed, squaring the trailing edge reduced this a little bit as far as I can hear which is not much. Will definitely align the fibres alternating off axis every second stack!

 

JulianB

Super Anarchist
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1,410
Sydney mostly
From memory Josie stayed in Aus post the dec 2008 worlds, though she was one of 3 ‘josie hulls’ from the same mould with one of the hulls being modified at some point. Possibly it could have been Wonk, Steve’s trial boat to the proposed rules was around still then, I am not sure what other boats Steve & Dave had at that time.

Occasionally I have heard some high pitched vibration/humming on the reaches at the higher end of speeds i have managed, squaring the trailing edge reduced this a little bit as far as I can hear which is not much. Will definitely align the fibres alternating off axis every second stack!
Give me a few hours ( I'm at trivia) and I'll give you some ideas ( can't send a lightbulb)

 

eliboat

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From memory Josie stayed in Aus post the dec 2008 worlds, though she was one of 3 ‘josie hulls’ from the same mould with one of the hulls being modified at some point. Possibly it could have been Wonk, Steve’s trial boat to the proposed rules was around still then, I am not sure what other boats Steve & Dave had at that time.

Occasionally I have heard some high pitched vibration/humming on the reaches at the higher end of speeds i have managed, squaring the trailing edge reduced this a little bit as far as I can hear which is not much. Will definitely align the fibres alternating off axis every second stack!
Wonk still around.   There she is this morning.  

image.jpg

 

JulianB

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Can't remember when, probably post 2012 because that the year Dad died, and Bruce Kirby was mortified that he had not meet dad, so I was the next best thing (apparently, or he was just sucking up to me).   Bill Crane set up a great lunch, 3 hrs in some little hamlet in RI, then I ened up with Steve (Clark), stayed the night at the ranch (Steve's house) and we drove with at least 2 IC's in tow from Newport RI up into Canada and on to Ottowa to race in a weekend event, a very young Dave was with us, talking shit (Steve and I were, Dave was probably thinking "2 stupid old bastards").    They ofcourse flogged me, but that was always going to happen.   The last time I sailed a IC was one of Uffa Fox's original boats, something like 3,000 brass screws all lovinging removed and the pannels all came off, where repaired and replaced, this was somewhere near Manchester in the UK on a river, the guy (heavily into Rolex thermo plastic) could not bring himself to sail it, and insisted that I did, which I did, not sure it was ever sailed again, but the late great Ian Bruce was with me and very very envious.

In 1959 my parents had a choice, emigrate from NZ to Sydney or LA, Dad like LA, Mum liked Sydney, Mum won.    But I often think that if I had ended up in LA and the Bethwaites had ended up in "Merica" what would have been the downstream consequences.    IC's would have been in the somewhere.

                           jB

 

JulianB

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Sydney mostly
Boats all packed up on its trailer, inc the Winglets

image.png

off at Sparrows fart in the moring (5ish) to meet Davbe Lambourn who is driving down from Brisbane as I type this, load him up, talk some shit and do breakfast, and hopfully the painter will come up and have a look at the boat so he knows what he is up for late June, early July, so it's all happening.

Another call today from another person wanting a "89er", it's getting a bit scary, and it will be a lot of fun if it all comes to pass.

Other big thing, my mast is mid the ditch (Tasman sea, between NZ and Australia) and shoudl arrive in Brissy June 2nd, with any luck I will pick it up June 11th (got a wedding on the Gold Coast)

Huge week doing winglets, you can just see the gasket on the stb side, Pt side should be a breeze having learnt so much in the last 4 days. 

It's really starting to take shape.

Stanno, I will get that photo for you tomorrow, promisse, just like me beers!
 

                             jB

 
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