John_p,
Do the t-foils prohibit (by aserting force) the use of standard kick-up stocks? What about a one-off Stealth stock that would fit the Blade gudgeon? I'd be glad to test it for you - just to see of course!

General gelcoat layers are 1 to 2 mm thick, mast coatings are measured in microns. Takes a whole lot longer to wear 1-2 mm down then a few microns.

Besides I have recoated/rebuffed and repainted my hulls a few times but never my alu mast.

Now I'm not saying carbon is bad, never did, just that I'm suspecious of carbon "simply" being superior in most aspects among which durability. But I'm happy to agree to disagree. No disrespect intended on my part.





Indeed, we can wait quite a few years for that. And labour costs needs to come down as well. Humm, this is maybe a bit too sarcastic, Please don't take offense, none intended.

Sure alu masts costs when only building a handful of boats, you have to order a minimum of 40 mast, but when building around 20 boats a year or more (all the succesful classes) then extruded alu masts can be inmensely more cost effective from the builders perspective then carbon masts. We can easily be talking about a 1000 bucks difference per mast. Now I know that you Darryll have a different opinion on this and I understand your reasoning. Indeed in a batch of 40 mast you will have several crooked ones that you need to through away. However I've been involved in several superwing mast orders and I know exactly what it costs. Even with the discarded mast and shipping the costs of aluminium is very attractive compared to carbon when building a series of boats beyond 20.

It will not be easy at all to see carbon masts beat that.

However, Stealth Marine is doing it and they are, afterall, the most inexpensive F16's available (big credit to John Pierce and Sue). And I'm looking forward to you putting on carbon masts on your F16's as well.

The secret here is in-house production of carbon mast. If you have to get them from a supplier then forget about any serious cost reductions. These supplier will have you pay for their carbon masts.

With knowing the costs of a 40 mast Superwing mast batch I can tell everybody that I don't see carbon mast completely replace the alu ones anytime soon.

Wouter

I think it is ronstan. And I have a ronstan personally and I'm fully satisfied with it. It certainly doesn't jam wioth sand and salt like the Harken recirculating ball rails. Hate those.





I thought/think that one of the stiffest setups is :

-1- inner bolts all the way through with a spacer in the beam.
-2- Outer bolts sunk into the beam with large filling piece between lower inside of beam and the head of the bolt. This piece must be of a material with a high compression resistance.
-3- Shaped beams (not round)

Of course the stiffest setup is the one used by the Blade F18. Stiffness on that boat is simply unbeleivable.

Wouter

What did they do different and can it easily be incorporated into the Blade F16?

Sorry, it can not be easily incorporated into the VWM Blade F16.

They took large round alu tubes and rolled them into a more rectangular section with large corner roundings. A bit like a boxed oval. This extra material and the stress hardening makes the beams stiffer for the same frontal area. The also ended up with a flat section on top and bottom of beam and used that to fit 4 bolts per side. The beamlanding is probably more rigorously reinforced as well. All together this lead to a very stiff platform.

VWM Blade F16 beamlanding doe not have the shape that will take rolled beams. Neither is there room for 4 bolts per side and we can't chance the stiffness of the beam landing much after the hulls have been cured.

Having said all this, I feel we must not loose ourselfs. The Stealth F16 is a very stiff boat in my personal experience. A very good achievement since F16's are build very light, less material to play with

My own Taipan (homebuild) is much more flexible. However I do not feel that my boat is too flexible for the racing I do. I feel both boats have ample stiffness for good performance and handling, just one has alot more stiffness. The Blade F16 of VWM should be noticeably stiffer then my own boat, while still being less stiff then the Stealth. In this way the blade should have more then enough stiffness for good performance and handling. I think johns test experience underlines this.

Lets not get obsessed with it.

One thing though, as standard the Blades are delivered with only washers under the bolt heads. Having a large block as depicted earlier should make the connentions stiffer (when a proper material is selected for the blocks). You could try that.

One other thing we must not forget is that during the first season you need to tighten the bolts a few times. The bolts will unscrew themselfs when they are still really clean and a bit greasy. Dirt and old grease will lock them up better. ALso the laminate work and bolt-beam setup will deform a little initially under the first full loads.

I had to retighten my bolts 5 to 6 times in the first season and each time I won alot of stiffness, and loose it again after 2 to 3 times of sailing. For all we know the Singapore boat could have been in need of that. After the boat has been properly broken in everything should settle down.

Also don't degrease your bolts when they are new. These Stainless steel bolts can fuse (cold weld) themselfs tight when they are too clean. You can never again undo them and you'll have to cut them out. So have them lubricated dureing the first season and just tighten them often. Following season everything should be alright.

Wouter

To add my comments, I sailed on the Blade the following day in Singapore. Thanks for the shorter tiller extension Jalani. I was told it was shortened the previous day.

Anyway, my immediate concern for the Blade and its potential is the stiffness of the platform. Coming from the Taipan, it is really, really soft in comparison. The hulls would move independently a couple of inches in different directions from each other. And the wind and wave conditions were very mild. To be competitive, you need a solid and stiff platform. Also the front beam needs to be able to bent upwards 4 or 5mm so when the rig tension comes on it moves to be horizontal. Can't quite get this with current dolphin striker arrangement.

Other things, removed the jib barber haul. This had been placed on to limit movement of the self-tacker jib along the track. Not really in my opinion necessary. Found that with different sheet tension the jib would find its own spot on the track, and with the barber haul any ease in the job-sheet would lose all power in the jib, and height.

Cunningham/downhaul really not a great system. Needs an internal cascading system which has been discussed at length on this forum.

We used the normal Blade-supplied rudders and they felt good. I actually had these on my old Taipan so good to use them again. Tacking and gybing smooth. Gybing a lot quicker than the Taipan, tacking about par.

Rig and sails essentially the same as Taipans (common mast).

Overall, the Blade has the potential to be a great boat. Just a few things that need to be overcome. All new designs do have some level of teething problems and the Blades are going to be easy to fix (I hope).

On the centreboard size, was the boat ever tested with long and narrow boards? The flyer A-Cats, Capricorns and the other new wave-piercing cats have gone to this trend. Interested to know if they were tried or not.

Again, this is was opinion from a couple of hours of sailing. My background has been on Taipans so that is where my base-boat comparison is based on.

In other news, I am in Europe. Once it warms up, should be around for a sail on the F16s. Will be based in London so the Stealth guys are the nearest to me.

JC

Seems like the Blade hull design has some great potential but the platform still needs some work starting with the steering....

That's not strictly true, or fair, Flying_Cat. The only reason that I was having steering problems was because of misaligned, borrowed rudders. The AHPC rudders were borrowed from a Taipan, but naturally, the T4.9 tiller bar was too short for the Blade. So we had to use the Blade tiller bar adjusted down as narrow as it would go to get the AHPC tiller arms in far enough so that the rudders were parallel when centred. Unfortunately it wouldn't adjust far enough, so (when centred) the rudders had roughly 2cms of toe out on the leading edges when compared with the trailing edges. That is a LOT! Despite this the boat sailed and handled pretty well (considering).

The VWM rudder/stock combo as supplied looks excellent and JC seems to confirm this above. It was just a shame that the Blade's owner was working on them when I used the boat...

JC - sorry about the tiller extension. I just wasn't quite able to get it out of the way as we had one of our 'moments' and I bent the end off it! It was just one of those things....

We didn't use the barber hauler either when we were sailing and I agree with your comments. If it was 'on' then that was after we came ashore. While I obviously agree that the Blade was not as stiff as expected, I don't feel that it is a 'major' failing. A lot of the Blade's ride comes from that movement and the boat responds well enough to gusts etc. I prefer a boat to be stiff but it is something that can usually be built into a boat afterwards if necessary. I did just that with my first, very old, tired and tatty Tornado. Just a weekends work with an angle grinder, epoxy, glass, aluminium blocks and assorted tools. Where previously I had been able to lift one bow about 6" before the other bow started to move, I reduced it to about 3"...
It is also entirely possible that David Adams needs to torque his beam bolts up again as that boat has been out in several breezy days over the last few weeks.

That should not have been the case. I wonder what causes this.

I did the math work on the beams myself, a favour to Phil and god knows I'm still no way close to leveling on the favours. And the beams of the Blade (both the homebuild and VWM versions) are stiffer than the Taipans in all aspects. So we should not find the cause here.

Phill tested three boats to check the math and he found the following ratios :

AHPC glass Taipan : 100 %
Homebuild timber epoxy Taipan : 97 % flexing of glass Taipan
Homebuild Timber epoxy Blade : 70 % flexing of glass Taipan.

(Stealth F16 felt at least twice as stiff to me, maybe more)

This is comparable to what the math showed.

The measured Blade was wider then both Taipans and using the round 80mm x 2 mm Alu tube for both beams. VWM uses a 90mm x 1.8mm at the rear and also a stiffer section in front, both beams are stiffer then the measured Blades round sections. And I fully expect the VWM Blade to be stiffer then the measured prototype.

The Blade should feel noticeably stiffer then the standard Taipan. That is also the comment of the testers. The Timber epoxy Blade that was build here in the Netherlands feel stiffer then my own boat and even the glass Taipan of Geert. Additionally the vertical flexing of the blade, in the used test setup, was measured in 1 inch plus something. If you felt a couple of inches flexing then something is definately wrong.

I wonder what it could be.

I think I will e-mail David Adams and find out.

Wouter

Thanks,

I noted this down.

Both Bart and I felt that something like this would be the case. The only uncertainty we had left was whether it was possible to hurt speed significantly but not having the boat in the right attitude. I mean what if you sat to far back on the boat that is still kept level by virtue of the T-foils ? There is no way of telling whether the weight balance is just right, with the T-foils only engaging momentarily, or whether the weight distribution is off but corrected by permanently engaged T-foils with related additional drag ?

What are your experiences on that ?

Wouter

Yes, I'm sure it's possible to hurt the speed of the Stealth by sitting in the wrong place, and forcing the rudders to do unnecessary work (just like any other boat).
It's easy however to find the right place to sit... if you pull the securing pin out of one of the rudders, when the T-foil is running parallel to the surface and doing no work it will just slide up and down in the stock as you go over waves. If it's permanently stuck down you are too far forwards and if it just slides up you are too far backwards.
However because the T-foils compensate, fore and aft trim though still important, isn't as critical as it is without the T-foils.

Going back to the C/Al mast point - one of my club's Hurricane sailors wrecked his (Al) mast when a shroud managed to escape from the spreader. He had to wait over a year to get a new one as there were no blank sections available anywhere and the company that makes them wouldn't make any until they had orders for (I think) six. If it was a C mast (a) it might have been fixable and (b) he'd have been able to get a replcaement made straight away.

Working on them?

Hi John,

I think you have sold me on T foils, downwind is a major problem on Altered in highwinds. I think I may have to look into them.

Yeah I know I am a slow learner, it's only taken capsizing downwind every second race for a year, to convince me that Altered needs T foils.

Regards Gary.

Hi there,

I am following the discussion about the carbon mast, to explain a littlebit we (my father and me)are making carbon masts for A-class all around the world and there is a note that there are only weak , medium and stiff masts but this is not right. If you want we are building the mast to the spec of the sailor, this means weight of the sailor, sailmaker and type of boat and there is no price difference between this. There is also a note about the strenght of the mast, the carbon mast now a days is much more superior to the alu mast. The weight reduction is one of them but when you build the mast the right way with the right material it is stronger ( can load more stress) and bends the way you want it and even on the place where you want to have the bend. This comes with an experience of building masts for 1996 and takes ofcourse a lot of years to find out. When you do a pitchpoll the older mast could break but now a days the masts we are building don't have that problem as far as we know, only when you fall with you complete weight in the middle of the mast then there is a change of breaking. The last comment is that mast we are building from 1996 are never been spray paint or so ever and there is from 1996 up to know nobody who ever did this to protect against UV because the resin itselfs is designed with a maximum possible resistance to UV. This is ofcourse not 100% because that's not possible, every resin has influence of UV, even gellcoat (the reason why gellcoat gets a littlebit yellow after a while). I am sailing with a mast of 4 years old now and there is no problem at all with that mast. My upinion is that when there enough carbon avialable next year or so that the carbon mast get cheaper and that it will replace the alu mast. Specially when you are talking about classes where development is one of the issues in the class.

Thanks,

Hans Klok

From personal experience Hans, I couldn't agree more. The questions/critisism that has been expressed about carbon masts mostly seems to be "theoretical" coming from people without any personal experience/use of masts made from carbon - a little like someone talking "expertly" about "the joy of sex" without having experienced it.
After you sail for a while with a carbon mast, I don't think that you would ever go back to aluminium, even if it is just for the comparitive ease of stepping it, let alone for the other "joyous" characteristics from it under sail compared to aluminium

Our initial moulds for T foil rudders and stocks are in their final stages GARY. When they are finished we will be putting them to the test to work out what could be a few "unknown" eccentricities with their “rake angle” on the boat, they are of a similar principle to the “Stealth” system, that is they are push up, push down vertically in the stocks. This in itself MAY need some refining as the percentage of the leading edge of the rudder relative to the extended pivot point of the gudgeons varies with their relative height position in the stocks and when one hull is raised out of the water a similar thing happens which may affect the steering detrimentally. Until we fully test the system we won’t know the final outcome, although from all reports, none of this seems to be of any concern with the Stealth system. When we have the system fully functional we will make them available to anyone who wants to put them on their cats. The stocks being moulded in carbon makes it a relatively simple job to adjust them in the lay-up stage to suit any catamaran transom.

The daggerboards i've seen for my future boat are tested for strength, one person can easy stand on it. I've ordered a carbon Blade and the daggers are also carbon but not the mast. I haven't sailed on many catamarans before and hope the boat doesn't go upside down.

Mirjam
the Netherlands

Welcome to the forum, Mirjam. When do you get your new Blade? Is it coming from VectorWorks?

Paul

I ordered my boat in the Netherlands where I live. the company is Dynautic and they build the Blade and other carbon parts.
Mirjam