ETNZ IACC120 Dual build thread

see:

page 1 - post 2 Zip file
page 2 - post 20 mounting drawing, here you can see also the 34.5mm you look for.
page 19 - post 188

The quote 134mm is always marked

Drawings revised recently to introduce centering new data that can be downloaded from Matthias site.
cheers
Claudio

Claudio

Just to understand things properly:

the 134mm distance you are giving between S10 and S12 as well as the 99.5mm distance between the sections s10 and s11 are for the boat NZL-92 ?

I might look a bit daft, but cant find the posts you mentioned to download the rest of the drawings for Alinghi SUI-100.

Roman

Roman,

the site is :

http://iacc120cup.altervista.org/

The distance between frames, on my drawings, is equivalent to 1/10 of the LWL of that model

The Alinghi SUI-100 plans here below

Claudio

Thank you so much Claudio, and shame on me.

I downloaded the Alinghi SUI-100 plans from that site a while ago, and never checked if there was a newer version of them available… and voila, in the Revision C all the measurements you are referring to are there…

My apologies and thank you again for everything you are doing to promote this sport and getting new boats out on the water.

a very inspired
Roman

PS: cant wait to get home from work to continue work on SUI-100

Just returned from the regatta on lake Mirabilandia in Italy, the 1,600 km drive was well worth the knowledge & experience the Italians openly shared with me.

A big big thank you to everyone including Matthias, Alessandro & Alex and the Italian IACC 120 community who are all a great group of people who are all very enthusiastic about our sport & I especially love the Italian flare and their competitive racing spirit.

The wide range of designs and ideas was very interesting and I found some common themes that have made me re-think some areas of my project with following notes:

  1. Everyone is using 6 volt Lipo (light weight)

  2. All boats are using external sheeting system for easy adjustment and no-one is using sheeting through the fairlead tube as everyone I spoke with citied that the sheeting twists around servo lines inside the hull.(re-do sheeting system)

  3. Keel fins were mostly around 100 gram range (completely carbon) with very thin cords 6 mm and less. (build new CF fin)

  4. All boats were using carbon masts (weight saving) which are relatively inexpensive from 18 Euro for round mast up to 85 Euro for foil shape mast, I paid 45 Euro for alloy mast which is far too heavy at 180 grams.

These are the modifications that I will be making on my project now.

Saturday morning practice started in very light air and progressively got stronger throughout the day, causing lots of re-adjustments between racing and the professionalism of Luca showed him leading the table with equally good Matthias second (with radio interfernece problems) at the end of the first days racing, unfortunately I was unable to stay for Sundays program so hopefully Matthias, will give us the final results of Cup racing on Sunday.

Claudio, I’m convinced that the ETNZ is the best hull design for all weather conditions …one eyed kiwi speaking here :wink: … and my Italian hero (Alessandro) gave me the opportunity to take the sticks on his new ETNZ … man-o-man what a wonderful sailing experience!!!

Cheers Alan

Don & All - Today I received a very complete and informative response to the question of “post cure”. Since this is a response that may take up a life of it’s own, I will start a new thread in “TECHNOLOGY” and post answer there. That way I will not intrude on Caludio’s forum topic with a post that may have a broader range of interest.

Hello to everyone!
I’ve been very happy to meet Alan and his sons. I hope we’ll meet as soon as possible with your new boat!!!
On my semifinal against FlY Emirates New Zealand, I was in advantage 2-0 but, cause a contact with NZL-92, I broken a front hatch and during the start of 3rd regatta my boat submerged complitely! However the boat has been get back, and grace to my good work to waterproofing the electronic after 20 minutes I was in water again to complete the races. Unfortunately the sail servo begins to work badly, especially sailing close to the wind, every time I changed the direction, I was obliged to work with the trim because the servo end stroke adjustemt changed every time… so the semifinal and the final the boat wasn’t 100% of its potential. It has been very hard for me.

This is the final results of IACC 120 Italian Cup:

I used a internet translator to share with you the review of the IACC 120 Italian Cup, it is not perfect but you can read the sense of the review enough well I hope…

http://babelfish.yahoo.com/translate_url?doit=done&fr=bf-badge&trurl=http://www.iacc120cup.altervista.org/&lp=it_en

Cheers

Mat

Here one of the semifinalists, the TNZ-92 of Alessandro. interesting, for me , is to note that this result is obtained at the first participation to the National Championship - My congratulations to Luca the winner and to the other finalist Stefano as well :

Claudio

Claudio, thanks to all participants, thanks to everybody…

TNZ is a good boat, I am sure that has great margin for improvement, having to choose a new boat, I would like this one !

My Shosholoza has reached the maturity , and these new boats are getting me nervous !

I have already taken some counter actions and I will remove the printing decoration from Hull cheasing some cents of knot, hoping tha twill be sufficient…

Alexander congratulations for the beautiful competitions TNZ vs +39 .

A personal opinion/view:

I would hate to see the class remove logos and paint in an effort to go faster. I think that a lot of the visual appeal of the class is that the models “LOOK” like the real boats.

Institute a minimum weight rule if you must, but please leave the logos and designs on so they look like boats - and not unidentifiable models.

Only my opinion, but if you remove the paint, there will be much less class appeal to spectators - in my opinion.

Dick

don’t worry , was a joke but next time the images will go under the last skin

Thanks Luca -was worried for a moment.

Dick :wink: :stuck_out_tongue:

X2. Having them look like real boats is huge plus!

Hi Luca, regarding your comments on finding more boat speed, on the first morning of IACC Cup I was looking at how everyone set-up for light air and one point that surprised me how almost everyone had shiny polished hulls and I noticed big wave along the water-line of the hulls (unwanted energy)

I asked the question of Matthias if anyone had tried to reduce the hulls turbulence flow by lightly sanding the hull/keel/rudder with #600 to #1000 grit wet/dry sandpaper to get the benefit of laminar water flow ?

When racing on big boats I was always taught to never wax/polish the hull as this repels water away from the hull which causing irregular water flow that generates turbulence and drag. When you lightly sand the hull in direction of bow to stern or visa-versa, this makes the flow evenly in one direction as the water sticks to the hull in a microscopic layer (without turbulence) which helps makes you go faster, particularly in light air.

I have sanded the hull on my 1 metre RC yacht in the direction of the water flow using warm soapy (dish washing soap) water to lightly sand with. This helps by not dulling the finish of the painted surface as much and I find the result is quite noticeable.

Does anyone else do this ? or is this an old sailors myth ?

Cheers Alan

On the past, I tested one 3M polish used also for cars, but honesty I didn’t notice differences. My opinion is that it increases the performances on our models only if the wind is very very low (up to 0.5 knots), but over the wind energy is much more intense than the reduction of drag help. A model boat is not a real boat: the ratio between wind intensity and hull surface is considerably larger than a real boat.

The final evidence is the performance of many boats that use stickers on the hull. The “step” between hull and stikers is noticeable but the performances are not affected. Shosholoza RSA-09 has stickers; my Alinghi SUI-100 has stickers and many other top boat use them and they win.

Mat

Conclusion ?

The WINNER is NOT the BOAT but the SKIPPER !

Champions change the boats but continue winning !

The lateral wave, more visible during running, is anyhow formed by the hull draft . This is why I tried to reduce on my design the hull deept hoping on some benefits.
Smothness is a complex argument where Reynolds laws are totally involved.
Sanding the surface is a sort of trial hooping to imitate fish skins without the production of polymers substances, etc. etc.

My simple suggestion for the candidate winner :

Two boats , one for low wind and one for strong wind .

“Wash and Clean” as often as possible in one day because at every race the surface will collect a lot of microscopic dirty molecules and if you run for a winning place don’t forget the TUMBS and good SAILS.

Cheers

Claudio

I thought this might be a great article just to prove … nothing ! :smiley:

Is interesting, and loved some of the background history, and am now working to get my daughter-in-law to see if she can get some “riblets” out of 3M where she works. Anyway … enjoy as it appears there is no real definitive answer of wax/polish vs. wetsanding. Enjoy the article.

What’s the Best Finish for My Boat?
© 2009 Greg Barton

I’m often asked, will waxing my kayak make it faster? There are two schools of thought here. The first is that waxing will make the hull surface smoother, slipperier and faster. The other is that wax causes water to bead up on the hull and the added surface tension actually makes your boat slower. My experience has been that neither is true, but read on for some practical ideas on how to achieve a good fast surface on the hull of your kayak or canoe.
I’m always hearing tales of how a particular surface finish will make a boat faster. I remember way back in the '70’s that a chemist told Olympic Canoe finalist Roland Muhlen that covering his canoe with Teflon would create a low friction surface and make his canoe faster. So Roland covered the entire surface of his canoe with Teflon film. While Teflon has amazing low friction properties between solid materials, it’s similar in friction to most other materials between solid and liquid (or hull and water). Roland found no speed improvement, so removed it from his hull. But it did have one side benefit - he left in on the right gunwale, which provided an excellent rub strip for J-stroking!
Such is the case with most other “low friction” surface treatments that I’ve seen. When tested, most of them make little or no difference in boat speed. I’ve only seen two things (so far) that make a significant difference in speed - and both have been banned by the International Canoe Federation for racing.
The first is a slimy polymer compound applied to the surface of the boat. This compound dissolves in the water, lowering the viscosity of the water next to the hull and reducing drag. As it dissolves it comes off until it is no longer effective (leaving contaminated water in your wake). During the early stages of the race, the polymer did its magic giving a boost in speed. By mid race, the polymer was gone and they completed the race with no further advantage. But still - they had a nice boat length or so benefit (so I was told) in the first half. The following year, the ICF banned the substances and started requiring that all race boats be launched from a single dock. That dock has a race official with a sponge and a bucket of water. He sponges some water on the hull of each boat, checking to make sure there are no slimy substances.
The other item that really works is a “riblet” material manufactured by 3M. It is an adhesive backed plastic film with very fine grooves machined into it (similar to the grooves in a phonograph record). The size of the grooves is matched to the density of the fluid (water in our case) and the speed of travel so that the grooves dampen the turbulence of the water as the flow detaches from the hull. The grooves need to be carefully aligned so they are parallel with the flow of water over the surface. 3M donated some of this to the US national team in 1986 and we tried it on a few boats. I raced one of the boats in the heats and semifinals of the World Championships in Montreal, winning both preliminary races. However, I was “outed” by a bunch of kids. After each race, the top finishers are required to go to boat control, where your kayak is checked to ensure it meets specifications, including minimum weight. In order to get a consistent weight, the boats are dried with a towel before weighing. The kids drying the boats noticed that my kayak had an odd feel to it as they rubbed the towels over the surface. The towels seemed to “track” lengthwise down the boat, and had a lot of friction (and made a “zip-zip” sound) if wiped quickly across the grooves. Soon there was a whole crowd of onlookers and officials gathered around my boat. It became clear that I would be protested and likely disqualified if I raced that boat in the finals. So I switched to another boat without the riblets for the finals. I finished 5th, just over 2 seconds behind Jeremy West, the winner of the 1000 meter event. If I had raced with the riblet boat, I likely would have won the final (although it would have been close) and then promptly been disqualified.
The ICF expressly banned riblet material shortly afterwards. However, I did win the 1000m World Championships the following year by an incredible margin of 3 seconds, paddling the newly designed Ted Van Dusen Eagle. 3M later mentioned in promotional material that they had supplied riblet material to the US Canoe & Kayak team. The East Germans immediately jumped on this, insisting that I must have used the material on my boat in the 1987 World Championships - feeling that was the only way I could have won by such a margin. The following year Norman Bellingham & I raced the same K-1’s at a competition in Brandenburg, East Germany. When we crossed the finish line, the boat control tent was swarmed with German officials armed with stereo microscopes checking every square inch of our boats to see why we were paddling so fast. They found nothing, but it made for some good excitement!
So where does this leave you? The best advice I can give is that you want the surface of your kayak to be as smooth and clean as possible. While “magic” surface finishes are unlikely to increase your speed, a smooth surface WILL make you faster. The smoother, the better. You don’t want any bumps, scratches, or dried on crud disrupting the flow of water over your hull. If your hull is rough or oxidized, start by wet sanding the surface. Use progressively finer and finer grit sandpaper, all the way down to 2000 grit if you can find it. While 600 grit is the finest you’re likely to find in most hardware stores, auto body supply shops usually carry the ultra fine grits. Once you’ve sanded the surface perfectly smooth, use polishing or rubbing compound to make it even smoother. An orbital buffer with a nice soft pad will give you the best finish. Now you’re ready to race.
Another question I often hear - rather than polishing to a mirror like finish, wouldn’t it be better to end with 400 or 600 grit sandpaper, sanding lengthwise down the boat to create a riblet effect? My answer is NO. It is impossible to sand accurately enough to keep the sanding grooves perfectly straight and parallel down the entire length of your hull. The only way you could accomplish this would be to use a CNC machine or robot to do the final sanding. If you succeeded with a machine to sand that accurately and raced it in an ICF controlled event, the stereo microscopes in boat control would pick this up and disqualify you. It’s far better to just make the surface as smooth as possible, without worrying about which way the sanding scratches are oriented.
Now you may ask “but what about wax, should I then put wax on my polished hull?” The answer is that it’s a matter of personal preference - it probably won’t make much difference! One reason it may help, is by keeping your hull cleaner. If you are the type of person that doesn’t like to clean and dry your boat, then wax will keep it cleaner (allowing water scum and other grime to slid off more easily), resulting in a faster hull. If you keep your hull perfectly clean after polishing, by rinsing and drying after each practice session until race day (and keeping it out of the sun to avoid oxidation of the surface), then you’re probably just as well not waxing it - in case I was wrong and the surface tension caused by wax really does impart 0.001% more drag!
By the way, all Epic Kayaks are polished with a high speed buffer before leaving the factory, so they are ready to go when you buy them. However, if your boat is older and you notice the finish is not as smooth or shiny after exposure to sun, saltwater and/or pond scum, then a good cleaning and polishing (with or without wax) will put some more speed back into your boat!
So go ahead and wax your boat if you are so inclined. It will keep your boat cleaner and help protect the surface from UV light (you can also products such as 303 Protectant that will preserve the finish of your boat). While the wax may not give a noticeable drag reduction compared to an otherwise clean, smooth hull, it just might give you a psychological boost knowing that you have the shiniest hull in the race!

Oh - by the way, I “AM” positive this Beneteau could use “something” !
Photo courtesy of SAILING ANARCHY !
:scared: :smiley:

The video of IACC120 Italian Cup 2009:

http://www.megavideo.com/?v=NGXE5IKD

Cheers

Mat

Yes your right Claudio, at the end of the day it’s comes down to 80% hardware (boat design & set-up) and 20% brainware (the skipper)

Dick a very interesting article thank you, I was reasonable close to an Olympic water sport quite a few years ago in which our team won gold, the wooden hull of the boat was sanded by hand, whether it played a significant role is obviously no clear … everyone to their own uh ! but love the barnacle example of how not to look after a hull.

After my IACC trip I had long think about making modifications along the lines of the Italian boats and decided to stay with internal my continuous sheeting system. The reason is that I want to keep weight as low as possible and eliminate as many possible water entry points on the deck.

Therefore sheeting stays, leading through a single fairlead CF tube and is joined it to the winch line below deck with a small swivel. Have tested it for few hours and cannot get the line to twist or tangle. If I run into problems later I will change to external system on my second boat.

Today I was planning on closing the deck (epoxy to hull) and last minute precaution walked down to the local village water trough for water testing the hull, if there was going to be any leaking I was expecting it to around keel or rudder fin area, but I found after not more than 1 minute water migrating through the fibreglass where are no fittings or holes in the hull !!! :confused:

Looking at the pic below you can see water formation, the hull has 4 layers of Fibreglass and has been primed with undercoat paint, repeat test 3-4 times with same result.

Further checked the hull with magnifying glass :magnify:and there is no obvious hole :confused:

Can some-one give me some idea why this is happening and how to properly fix the problem. :help:

Cheers Alan

Alan -

I had this happen only once before - and I felt it was due to using 6 oz. glass instead of customary 4 oz. that I usually selected. The pinholes seemed to come from either dirt or fabric coating. I was able to sand the area lightly on the inside of hull, and then used thinned epoxy to paint on. (Used acetone for thinner) It seems the epoxy eventually found the pinholes and filled them. On my 1 meter multihull, I still have one that has a bit more leakage than yours - but over the course of about 2 hours of sailing. I tried fixing that - but gave up and just use a sponge. Some are difficult to track - much like a roof leak. The water could migrate between layers of cloth coming out far away from where it entered.

Perhaps - mark the areas where you see leaking, and use a “Q-Tip” applicator - or vinyl glove and finger and smear epoxy only in those areas. Exterior gel coat might work - but adds weight. Most all “big boat” fixes required a bit extra resin to be added (smeared) on the pinholes to stop leak. My Gougeon book (WEST SYSTEM) suggests it could have been a spot in glass where the weave wasn’t quite filled with resin, or in a sharp corner/bend - but your “appears” to be coming on a curved but relative smooth surface.

Best advice I can give - since one fix worked for me, the other didn’t.

Dick