AC Developments and boats in build

[SteveC]

Aussie guys,

Your comments on the new rule IC are of interest but should not be on this thread. If you wish to start another debate about the virtues (pun not intended) of each design I suggest we do it elsewhere. This thread is for the discussion on AC development only so please respect this.

[SteveC]

Haydn,

The "canyon" did sort of develop from an existing pole from Rob which was modified, in retrospect a mold would make this a lot easier to construct and make the additonal framing unecessary. However there is a fair bit of load on this so I aired on the cautious side and as it's my first canoe its a case of knowing what I can get away with. The beams are there to make it easier to stick the foredeck down and mount the chute mouth but I may take these off if they become unecessary.

If this approach works and makes conversion easier the whole thing could be simplified with a couple of molds taken off the finished boat and end up with just a foredeck replacement.

[H Virtue]

Aussie guys,

Your comments on the new rule IC are of interest but should not be on this thread. If you wish to start another debate about the virtues (pun not intended) of each design I suggest we do it elsewhere. This thread is for the discussion on AC development only so please respect this.

Fair enough, I guess I felt I had to respond on the views posted earlier on the IC-AC issue, I wont hi-jack the thread anymore.

[Barry Watkin]

Mudman, Re your chute taking in water. I trust youve noted that Robs chutes have a drain fitted under the mouthpiece, existing the hull throught the hull adjacent to port.
When I converted 176 I couldnt do this as like you I did the marine gynaecology bit & left the decks (very pretty sepele) on during the conversion. If you limit how far your kite comes in, ie
leaving 6/9 inches out I didn't suffer too much. I might have a pic or two of the drain, if I find them I'll send them over.
On another note my reason for converting an IC appears as yours, most of us (in UK) sail the majority of time at club level in mixed fleets and if you are on tidal waters that run against the tide in the light stuff is deadly when you have spi clad boats all around you. Even Andy in his uni-rigged 'IC' finds that tough 30kgs lighter or not.
Have fun regards Barry ACbecause we like it that way!

[Steve Clark]

IF you will accept input from someone who shouldn't be commenting on this thread.....
Do EVERYTHING you can to keep the LCG ( longitudinal center of gravity) as far aft as you possibly can. You have lots of structural efficiency available by putting the pole on center line and, You should maximize this to gain the advantages you are hoping for with the improved design.
It is more than possible to have the CG of an IC hull at the mid length. In my opinion this is critical.
SHC

[SteveC]

Of course Steve, always welcome to recieve input and advice from whatever source.

Does this mean ensuring the weight of the pole assembly is balanced by weight added slightly rear of the mid point?

[Steve Clark]

Of course Steve, always welcome to recieve input and advice from whatever source.

Does this mean ensuring the weight of the pole assembly is balanced by weight added slightly rear of the mid point?

Adding counterbalance is not as good as reducing the weight in the ends. You want minimum pitch inertia so not having the weight there in the first place is the right answer.
What I was trying to do was encourage you to remove about 1/2 of the stuff you have forward of the mast step because, in the US and Australian opinion, you don't need it and it will slow you down.
Seriously, all of the bending loads and fore stay termination loads will be handled by the hull skin, your "canyon" and the two bulkheads ( aft end of the sprit and the one art the front of the Canyon. Since you already have a watertight sub deck, all your foredeck needs to be is a pretty cover over bow that keeps miost of the spray out. A shower curtain with rubber duckies on it would do the task. So go light!
It may interest you to know that US boats haven't had any athwart ship webs under their foredecks in 25 years and have held up pretty damn well.
SHC

[jimc]

It may interest you to know that US boats haven't had any athwart ship webs under their foredecks in 25 years and have held up pretty damn well.SHC

Under the foredeck of 257, which is an earlier Razorback shell, I really don't have too much and I've seen no sign of distortion when the rig tension goes on. There's a roughly 2in by .5 in cedar core carbon beam down the middle, a full height spine for the first foot or so to distribute mast loads, the 3mm ply is doubled under the jib track and then nothing else until the bulkhead that takes the forestay and jib loads. The 3mm ply is otherwise completely unsupported.

[SteveC]

Thanks for the feedback guys. Will consider your input however the stringers shown are primarily there for another purpose which may become apparent when I get the foredeck on. Having said that I may cut them down a bit although the weight saving will be 10's of grammes I would think.

[SteveC]

Update on progress with Jet......pictures in gallery at http://www.intcanoe.org.uk/gallery/thum ... =20&page=4

Now fully decked with foam ready for fairing and top layer(s). Hopefully will be a clear carbon finish unless it looks crap in which case it will get painted.

Took a bit of time working through the chute details and seat rails which are below deck level but now in place on hope it all works out. Looks different anyway.

Have a new set of spars almost ready using latest high modules carbon producing a skinny 44mm mast section and ovoid boom with 50mm spinnaker pole. Will be mounting it all on Jet soon to get layout of fittings in the correct place.

[SteveC]

Time for a bit of an update.

Jet is now fully decked and is being fitted out before final layers of c/f and/or glass and painting.

New chute arrangement now in place and so far seems to work OK. New deck layout is making control line and fitting placement interesting but is coming together. I am going to have an option for a non pump system as per Musto Skiff to see how this works out as this is one reason, it seems for the exodus from the RS700 to the Skiff due to speed in getting kite up and down. May be trickey on the narrow hull form of a canoe but worth a try as it is so much simpler and will have less friction.

Aardspars have designed and built a new high modulus super skinny mast 44mm tube and a small diameter spinnaker tube which are also very light. The mast is based on Moth technology and should have similar stiffness fore and aft as a Proctor but stiffer sideways and similar to the new 60mm tube Superspars. Also a new super stiff but lightweight oval boom.

Foils - we now have a mould for a 200mm wide 64012 section made by Aardvark Technologies which I shall probably use and Alistair Warren has offered use of his Monkey rudder mould. Main jobs left is now paint job and of course the seat for which I also have some different ideas.

Latest pictures are posted on the AC - Jet Building an new AC section of the gallery on UK website at http://www.intcanoe.org.uk/gallery/thum ... =20&page=4

[Mudman]

Hi Steve,

The rebuild looks good. I tried a non-pump system last season when I fitted a kite to my old ship and it didn't work. Unlike other boats I've sailed where the helm pulls up the kite (2 man) you can't put the tiller between your legs to steer and pull with both hands in a Canoe. You can do this in the Musto Skiff. The result was a severe lack of directional control at the point where it was most needed. You also needed to be very fast on the hoist/drop to avoid sailing over the kite, something that happened on a frequent basis. Manageable - just - in a force 2, forget it in a force 4. The boat is now being rebuilt - pics up soon - and will have a pump system. The friction is better than swimming!
And having both a Skiff and an RS700 in the club, I'd be surprised if the reason the skiff is gaining numbers is simply because of the kite system. The Skiff just looks a better boat.
Cheers,

David

[charlie1502]

Looking good Steve, can't wait to see it out on the water. I especially look forward to seeing how the under floor chute works out.

[SteveC]

Update.

Jet's top decks all finished and clear coated - just needs to be flatted back and spayed with UV resistant coating. Bottom is about to be prepared and foils fitted.

New seat and carriage design underway - it will be different and may work .

Jet slanted small.jpg (141.9 KiB) Viewed 15667 times

I have uploaded some more images to the UK website under AC development/Jet - building an AC

[SteveC]

Jet gets launched New pictures in the gallery.

She has final hit the water and the development phase is underway. Ironically the new stuff seems to work well and the basics have caused me problems - mostly an underestimation on the forces being transmitted through the rudder - readily availlable information in one location on the website or a manual would have helped greatly through this whole process. I intend to pull this information together and put it on the website in the form of various guides from what has been learned and gleened from others.

New seat seems to work really well - takes some getting used to but the ability to shuffle up and down the seat is so easy. Haven't got to the stage of hanging off the end yet which may require a different technique but so far so good. Needs some foot holes or strops added to push out on.

Haven't really used the spinnaker in anger yet but walking around the boat is now much more pleasant and in the light stuff I can now stand in the middle with the seat extended which makes balancing a lot easier. The higher deck feels different and the height of the seat is comparatively lower but it does't feel less stable largely because you don't have to worry about tripping over the sock. I put a pump system back on principally because getting the leverage necessary to pull a rather large amount of material into a small hole is tricky. If we had smaller kites, hand over hand may be worth reconsidering.

From the limited time on the water she does feel really lively and quick and seems to float a lot higher in the water feeling much more like the Morrison IC. I will be refitting the ballast later this month to give comparison on carrying the extra weight. Haven't actually weighed her yet so not sure how much lighter she is. Will do this on Saturday.