AC Developments and boats in build

Use this forum to discuss the latest changes in the class
SteveC
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AC Developments and boats in build

Post by SteveC » Tue Aug 26, 2008 4:42 pm

I have started this thread to hopefully enthuse the AC community with thinking about how the class can develop within its own envelope with a standard Nethercott hull but with plenty of things to think about in deck and systems development. The DC has rightly taken the limelight over the last year but it isn't the only show in town and the AC I think needs a boost on this site to enthuse owners in what is still by far the biggest fleet worldwide.

I am building a new AC and will be using this thread to discuss new ideas on how the design can be improved. I have spent the last 18 months with Menace and have some ideas on how it can be made easier to sail and build which I will be trying out. The trick is to use the experience of the current builders but look at things with fresh eyes to see if improvements can be made.

The main design aims are;

1. Reduce weight to a minimum
2. Tidy up the deck layout to stop tripping over ropes etc. The spinnaker chute will be under the deck.
3. Some radical new ideas on seat design to reduce weight and the physical bulk of the thing.
4. New spinnaker pole arrangements with reduced friction and recovery system for ease of lift and drop.
5. Removeable cassettes for foils and inserts as a matched pair.

I am keeping notes and pictures as I go along with templates for all parts and hopefully if the ideas work out share this information with drawings. The shell is the tricky bit which is probably best produced by the builders but a kit of bits for the deck or a complete mould would reduce build time and costs dramatically.

From general discussions with various owners at the UK Nationals and people at our club who want to buy boats, the lack of standardisation is an issue. The average club racer doesn't want the messing about factor and if something gets broken doesn't want to sit on the bank for 6 weeks whilst a replacement is hand crafted. Standard items and designs should be available for dagger boards, rudders, seat and carriage for those who want them or at least adjustable to fit different boats. Rob Michael to be fair has moved some way towards standard parts for his boats, but spares are not available off the shelf.

Through the process of planning the new boat, all information and experience is largely in the head of the boat builders and there is no central databank of information. This site does not help the amatuer builder to make a standard set of parts even a profile of a centre board for example is not available. We need to look at sites such as the Cherub for inspiration where there are articles on how to do stuff and interesting items on boat design etc.

Any ideas are most welcome.
Steve Clarke (UK)
GBR338 "Money4Nuffin

jimc
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Re: AC Developments and boats in build

Post by jimc » Tue Aug 26, 2008 11:36 pm

SteveC wrote: We need to look at sites such as the Cherub for inspiration where there are articles on how to do stuff and interesting items on boat design etc.
I'm happy to assemble material into articles if its thought desirable. I've done a bit of that sort of thing in the past.

SteveC
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Re: AC Developments and boats in build

Post by SteveC » Thu Aug 28, 2008 9:14 pm

Cheers Jim, may take a while to get info together but thanks for the offer.
Steve Clarke (UK)
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Christian AUS
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Re: AC Developments and boats in build

Post by Christian AUS » Thu Aug 28, 2008 9:30 pm

SteveC wrote:I have started this thread to hopefully enthuse the AC community with thinking about how the class can develop within its own envelope with a standard Nethercott hull but with plenty of things to think about in deck and systems development. The DC has rightly taken the limelight over the last year but it isn't the only show in town and the AC I think needs a boost on this site to enthuse owners in what is still by far the biggest fleet worldwide.

I am building a new AC and will be using this thread to discuss new ideas on how the design can be improved. I have spent the last 18 months with Menace and have some ideas on how it can be made easier to sail and build which I will be trying out. The trick is to use the experience of the current builders but look at things with fresh eyes to see if improvements can be made.

The main design aims are;

1. Reduce weight to a minimum
2. Tidy up the deck layout to stop tripping over ropes etc. The spinnaker chute will be under the deck.
3. Some radical new ideas on seat design to reduce weight and the physical bulk of the thing.
4. New spinnaker pole arrangements with reduced friction and recovery system for ease of lift and drop.
5. Removeable cassettes for foils and inserts as a matched pair.

I am keeping notes and pictures as I go along with templates for all parts and hopefully if the ideas work out share this information with drawings. The shell is the tricky bit which is probably best produced by the builders but a kit of bits for the deck or a complete mould would reduce build time and costs dramatically.

From general discussions with various owners at the UK Nationals and people at our club who want to buy boats, the lack of standardisation is an issue. The average club racer doesn't want the messing about factor and if something gets broken doesn't want to sit on the bank for 6 weeks whilst a replacement is hand crafted. Standard items and designs should be available for dagger boards, rudders, seat and carriage for those who want them or at least adjustable to fit different boats. Rob Michael to be fair has moved some way towards standard parts for his boats, but spares are not available off the shelf.

Through the process of planning the new boat, all information and experience is largely in the head of the boat builders and there is no central databank of information. This site does not help the amatuer builder to make a standard set of parts even a profile of a centre board for example is not available. We need to look at sites such as the Cherub for inspiration where there are articles on how to do stuff and interesting items on boat design etc.

Any ideas are most welcome.
Some interesitng ideas SteveC, funnily enough I am about to build a new IC designed by Geoff Harman which comes with a lot of the main parts pre-assembled in a flat pack kit form. Which, if successful gives IC sailors the chance to go down a similar path together if they want. Lots more details will be on this when we start building after the Aussie Nationals in October.
Some decisions that we have made so far include using NACA 0011 foil sections, using the other Steve C's sliding seat model and other ideas which I'll write about once we prove they work.

For simplicity in an AC layout, I would seriously look at encouraging UK sailors to see if the other SteveC still has my old AUS018. Tim Wilson built this boat for me as IC/AC convertable - it is a below min weight Nethercott with a false foredeck which all the kite gear goes underneath, we used fixed capped stays (as opposed to the adjustables in the UK) and a hog stepped mast. We built a carbon roller to guide the kite into the spinnaker sock and set the rig back in the boat to have the chute fwd of the forestay. Still had a self tacker, but I had an auto jib car control which was set by boom angle (something I kept even in IC mode as it worked really well). All this stuff worked really well, but to be honest the kite made an ugly boat of the IC to me, so I never had a kite purpose cut for it (so it still had Gareths old one). All in all AUS018 was a much simpler boat than other AC's i've seen and whilst it was really unproven as an AC in regattas it did come 7th in the 2008 Worlds as an IC.

Image
Pic showing Chute and capped stays, spinnaker cleats are on Carriage
Attachments
cracking off for the mark - shows false foredeck
cracking off for the mark - shows false foredeck
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Steve Clark
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Re: AC Developments and boats in build

Post by Steve Clark » Fri Aug 29, 2008 7:27 pm

AUS 18 is indeed still resting in a nice little shed waiting for someone to tell her that she is lovely and ask her to come home with them.
She is indeed a beautiful boat, if a bit different looking than the standard Rob-craft, but Tim builds very nice stuff and she ought to be playing with other ACs.
And Kids, the dollar ain't going to stay in the toilet for ever, so act while your Pounds and Euros are worth as much as they have ever been.
I can even be nice with the price.
Will be sending Roger's GER 78 over the pond, and if we can add some boats, it makes a 20' container sensible.
Blue Meanie, could be reconverted pretty easily by a motivated party....
And then there is other stuff.
But I don't want to sound crass and commercial.
SHC
Beatings will continue until morale improves

petermclaren
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Re: AC Developments and boats in build

Post by petermclaren » Sun Aug 31, 2008 6:02 pm

Steve (UK):

Great to hear about your ideas for your new AC. I'll be fascinated to see how you put the sock under the deck and keep it drained to prevent dragging around a lot of extra water. There must be ways of making the seat and carriage lighter: have a look at what the new ICs are doing.

Do you think you will also save costs?

Peter McL

H Virtue
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Re: AC Developments and boats in build

Post by H Virtue » Sun Aug 31, 2008 11:26 pm

petermclaren wrote:Steve (UK):
There must be ways of making the seat and carriage lighter: have a look at what the new ICs are doing.

Peter McL
My new carriage came out at just over 2.5kg, I had a design change part way through its construction if I started again I think I could take out .5kg and if I went for a really low profile design maybe a little more could be saved. It hasn't been tested on the water yet going from what I have had success with in the past and learnt recently from some very experience builders in our class I don't expect major issues from normal use.

From what other have said earlier in the thread I agree simplifying the AC setup further would be a big improvement. The AC's that were at McCrae looked to me as being so cluttered they would have to be easier to sail if the "less is more" approach was taken, not to mention the $$ saving on less hardware.

Getting the kite under the floor would be good but not an easy thing to do. I thought Blue Meanie had a good solution of cleaning the deck up with the return roller for the chute.

H.

SteveC
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Re: AC Developments and boats in build

Post by SteveC » Mon Sep 01, 2008 3:18 pm

Peter,

I will post a picture on here soon when I'm sure it's going to work but basically;

I think you need to have the base of the chute which will be water tight and made of 4mm foam with carbon and GF layers with the lower inside face falling from front to back in line with the gunwale sheerline and roughly at the same level as the existing deck. The dancing floor is therefore raised up by 100mm at the V bulkhead and 45mm at the back end of the seat rails with a fall at about 30 degress to the gunwale and a channel formed in the middle to keep kicker and daggerboard levels the same. The central groove will take the spinnaker halyard and elastic takeup out of harms ways. The wider and flatter gunwale area is also intended to give a wider area to push off from and to stand on the gunwale prior to getting on the seat and will provide better leverage for moving the carriage and give more leverage whilst standing on the boat. I am moving the carriage rails inboard by about 125mm each side to compensate. The new raised profile raises the CofG of the driver a little but I am not convinced of the arguement that this makes a lot of difference based on the existing 20 foot mast and thumping great seat stuck up in the air which is far more significant for the short time you should be stood on the deck anyway.

I have built a prototype rectangular chute profile which is 3m long with a mouth of 250 x 100 and an exit of 100 x 45 to test and make sure the kite will exit and enter without jamming. It will fit across the frames and help to support the floor and seat rails as a stressed component and should only weigh 2-3kg.
Steve Clarke (UK)
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SteveC
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Re: AC Developments and boats in build

Post by SteveC » Mon Sep 01, 2008 3:30 pm

Peter,

Sorry missed the part on costs. The biggest cost is labour as far as I can see. Although carbon is expensive, you don't use that much and in fact mixing with kevlar and glass may reduce these costs further. With standard templates, a kit of bits could be put together to make amateur construction actually quite easy. The hull shell is however the tricky bit and should probably be left to the professionals. The eventual use of a deck mould would of course make the whole thing very simple but would require investment and of course some sales to generate revenue.

My spinnaker pole is currently running in a channel down the centre of the foredeck which if it works could make conversion considerably cheaper as it is requires only the foredeck skin to be replaced and a fairly simple bulkhead in the bows.
Steve Clarke (UK)
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Mudman
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Re: AC Developments and boats in build

Post by Mudman » Tue Sep 09, 2008 10:16 am

Hi Christian,

Aus18 looks very pretty. I'm interested in the auto jib arrangement - can you give any further details?

Cheers,

David
"No easy way to be free..."
IC 206 sailing out of Brightlingsea

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Christian AUS
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Re: AC Developments and boats in build

Post by Christian AUS » Tue Sep 09, 2008 11:30 am

PM sent - but remember that AUS018 is for sale. just contact Mr Clarke of the USA
Mudman wrote:Hi Christian,

Aus18 looks very pretty. I'm interested in the auto jib arrangement - can you give any further details?

Cheers,

David

SteveC
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Re: AC Developments and boats in build

Post by SteveC » Mon Sep 15, 2008 5:04 pm

H Virtue wrote:
My new carriage came out at just over 2.5kg, I had a design change part way through its construction if I started again I think I could take out .5kg and if I went for a really low profile design maybe a little more could be saved. It hasn't been tested on the water yet going from what I have had success with in the past and learnt recently from some very experience builders in our class I don't expect major issues from normal use.



H.
Howard,

Do you have drawings or pictures of your carriage :?: Is there anywhere details of carriage and set design with details of experience obtained over the years and successful designs as guide to the budding designer :?:
Steve Clarke (UK)
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H Virtue
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Re: AC Developments and boats in build

Post by H Virtue » Mon Sep 15, 2008 9:36 pm

SteveC wrote:
H Virtue wrote:
My new carriage came out at just over 2.5kg, I had a design change part way through its construction if I started again I think I could take out .5kg and if I went for a really low profile design maybe a little more could be saved. It hasn't been tested on the water yet going from what I have had success with in the past and learnt recently from some very experience builders in our class I don't expect major issues from normal use.



H.
Howard,

Do you have drawings or pictures of your carriage :?: Is there anywhere details of carriage and set design with details of experience obtained over the years and successful designs as guide to the budding designer :?:
There are some pic of the boat over at SA, I'll see if I have some pics of the carraige and post here if not I'll take some. I've had a two issues with the carriage on the first outings nothing major just a little light so in the end I think if I started again I would be around the 2.5-2.75kg mark, I have an idea about a more elegant design whcih I need to play with to see if I can make it work if it (stay tuned although its a little way off in the future sa I have other things I need to build first like a lighter plank)

BTW its Hayden not Howard

SteveC
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Re: AC Developments and boats in build

Post by SteveC » Tue Sep 16, 2008 8:41 am

H Virtue wrote:
SteveC wrote:
H Virtue wrote:
My new carriage came out at just over 2.5kg, I had a design change part way through its construction if I started again I think I could take out .5kg and if I went for a really low profile design maybe a little more could be saved. It hasn't been tested on the water yet going from what I have had success with in the past and learnt recently from some very experience builders in our class I don't expect major issues from normal use.



H.
Howard,

Do you have drawings or pictures of your carriage :?: Is there anywhere details of carriage and set design with details of experience obtained over the years and successful designs as guide to the budding designer :?:
There are some pic of the boat over at SA, I'll see if I have some pics of the carraige and post here if not I'll take some. I've had a two issues with the carriage on the first outings nothing major just a little light so in the end I think if I started again I would be around the 2.5-2.75kg mark, I have an idea about a more elegant design whcih I need to play with to see if I can make it work if it (stay tuned although its a little way off in the future sa I have other things I need to build first like a lighter plank)

BTW its Hayden not Howard
Dear Hubert,

Yeah, I realised I got your name wrong after I posted it - serves you right for signing H :lol:

We have talked here about doing a lightweight tubular structure for the carriage in aluminium and then carbon. What is the experience here on construction?

Stanley
Steve Clarke (UK)
GBR338 "Money4Nuffin

Barry Watkin
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Re: AC Developments and boats in build

Post by Barry Watkin » Tue Dec 16, 2008 9:36 pm

Steve, Any news on your new machine yet? or have you cut out the build process And bought Robin's?
Needed to wave the AC flag a bit as we cant let these IC(DC) types rule the website ( that should of lit the blue touch paper!) Regards Barry :mrgreen: xAC176
BMW

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