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Couple more images. The beam swings fore and aft for legal trailering; that is, if you don't shift hull in early hours on top of car and then the beam later. And this is early image; had to increase the size of the non-floats - as seen in above image.

frogbowbeam.jpg

frog7copy.jpg

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Sid is no more, got smashed into several pieces. All the broken stuff (7 bulging  plastic sacks) has gone to the tip. Main hull is on shore but very broken. Could be repaired, make a proa maybe ... but not by me, interest has strangely waned. Wing mast in two; could be repaired no trouble but no boat to put it on.

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Love your experiments!!! I assume you will be hoisting a mainsail up each side of the ‘D’ mast making it a soft wing(?) this is something I hope to experiment with on my bi plane rigged cat as the existing masts are round and easily turned into a ‘D’. What type of foil(s) are you using using on the main hull ( I can see a case offset on the bottom of the hull so I’m assuming there may be  two of them)? Are the foils on the floats permanently attached at that depth or is there any form of adjustment for depth or angle of attack? Sorry for all the questions but I’m totally intrigued!! Good luck with the launch and can’t wait to see it sailing. PS, I’m in the process of turning my 5mtr biplane catamaran tender into a foiler.

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Intended to sail today but I screwed up on the tiller head shaft connection (original has been lost somehow) so bodgied up a replacement from various other boat parts (of which I have a few) - anyway had to saw away cured epoxy and re-glue slightly higher on shaft.  By the time that semi-cured, tide was on the way out.

Yes, have tested hoisting the two schooner rigged mains from the Skimmer as a double luff main, works fine - but too small because they're from the 18 foot  boat. But they will give an indication of whether the setup will work.

Only a conventional dagger offset to one side of main hull (so to have a wider but still cramped entry down below). Sleeping there will be hellish - but not as bad as on Eric Eason's beyond cramped Buccaneer 24. I could put a small T foil on the dagger but that means it has to be semi-permanent ... unless you go for a swim to remove it from bottom. I'm avoiding this T foil main dagger because it would mean acquiescing to madman Doug Lord's harping on about the subject. But if Frog is slow to lift off (it won't be) will bite the bullet and become his friend again?

The float foils are fixed, main at 3 degrees AoA, upper at 6. Will suck and see. The beam could be set up to alter foil angles, if necessary.

Here's a shot of the rudder during build. Changed my mind and made assembly swing out/in for "ease of use." Formerly was conventional dagger setup. And here's the D mast.

frog4 copy.jpg

D mast copy.jpg

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Sorry to here about Sid :(

Hope you keep building and experimenting I love your work !

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Sailed today with the Skimmer's two mains set up as one to make a very reduced double luff main for Frog. Number of little problems, as expected; the rudder cam re-glued yesterday was still too close to deck so had to brutally sand deck and cam back with rasp, still not quite right but at least I could steer crudely. When gusts arrived Frog surprised by sailing with some speed and panache - slow in the light stuff though. Since the double luff main worked okay, have to get full size version built by Bill Barry; that is, if he still wants to be associated with my contraption. Have to say looking out leeward at the tiny floats is little unnerving but in the gusts the leeward float was flying clear, so foils definitely do their job. By the way, complete boat without sails weighs 127 kgs.

frogsail2.jpg

frogsail.jpg

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127kg?? - but thats without the mast?  How much is the mast?  And - lenght and the section measures? 

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No, that's including the mast - which weighs including running and standing rigging 26 kgs.

Height is 8.83 metres, including bearing and the section is 200 x 240mm.

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No, that's including the mast - which weighs including running and standing rigging 26 kgs.

Jesus Groucho ,great effort , very impressed .

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Really - well I seems to have a problem with the scale of the boat - no people onboard. But thats is a light boat....

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Had some correspondence and replied to questions from an Australian small boat expert and enthusiast; might be of interest:

"The upper foils are for when overpowered; didn't see that occur during test, breeze gusted up occasionally and then Frog felt not too bad with float lifted clear, riding on lower foil (plus rudder too of course). There was no breaching, platform is steady. I realize that the tip must be close to surface but the platform heels so it must be down enough. Early days, lot to observe and learn. The main foil area is not large and I may have to increase the span - but in past foils I've found too large an area to be pain in arse, boat starts to lift too far, then rocks to other side. So prefer smaller area. Must say Frog seems a very small and flighty boat compared to my others, whole boat with rig weighs around 130 kgs, including Skimmer's "double" sail. And will be probably overpowered with full sized main. That's okay, I like flying along in light airs, magical.
I think the double luff will work out okay; looking at rig when sailing it sets smoothly with pleasant curves off the D mast to windward and to leeward.
Reefing will lower power but then I will have some turbulence set up behind the upper bare D mast section; have to live with that. The mast has luff of 8.6 metres, which is not excessive proportionately - compared to my other boats.
A Moth has, to my eye, a very fine mast, meaning  width/chord measurement - so drag is not really a problem but larger boat needs a decent stick. Frog's is 200 x 240mm, weighs with rigging 26kgs.
I find it odd that the A's haven't got a decent airfoil mast that works; maybe they're just too small and too light a platform to handle the slightly heavier rig. Could you imagine a C Class today without a full wing? Or even 3/4 decades ago without a wing mast?
The first sail revealed a number of mistakes with Frog but I'll get them sorted and when the new sail arrives will be another steep learning curve. Looking forward to it."

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Nice Groucho.

The reason for the A-Cat not going to a solid wing is the current rig setup works brilliantly across a wide range of conditions and 10 years ago the best rig guy in the world couldn't build a wing sail that was the same weight as the mast+rig. Add to that the hassle of rigging/transport and the inevitable wing breakage in a capsize and it hasn't made inroads.

There are some efforts on the D-tube mast over in A world, so definitely keeping an eye on this. One potential issue is getting the mast to bend correctly. How are you finding hoisting the double luff sail?

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Well, the make do setup using the Skimmer's sails, meaning the double luff sails are shorter compared to envisaged full size main, creates no problems hoisting. They have to be hoisted together  and as the sails go up, (talking about the couple of times I've lifted Frog's make do main) I lash the batten leech ends together. Another way would be to first unclip the angled down boom from its position, hoist the already batten leech attached sails, then when up get in between the two sails and reattach boom to mast.

Because of D wing mast and usual teardrop shaped wing mast stiffness, there is little bend so you have to live without the flattening ability of conventional bendy rigs. Like to hear what cat experts have to say about this. Wing mast mains, I've found, are completely flat and you rely on mast rotation to alter sail shape?

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Well, the make do setup using the Skimmer's sails, meaning the double luff sails are shorter compared to envisaged full size main, creates no problems hoisting. They have to be hoisted together  and as the sails go up, (talking about the couple of times I've lifted Frog's make do main) I lash the batten leech ends together. Another way would be to first unclip the angled down boom from its position, hoist the already batten leech attached sails, then when up get in between the two sails and reattach boom to mast.

Because of D wing mast and usual teardrop shaped wing mast stiffness, there is little bend so you have to live without the flattening ability of conventional bendy rigs. Like to hear what cat experts have to say about this. Wing mast mains, I've found, are completely flat and you rely on mast rotation to alter sail shape?

This is a fantastic project - really amazing work, post more photos!

I designed some WS sails for a rotating D mast in the 90s - I designed in a basic camber flow and twist via seamshape, and was able to get controllable, dynamic leech behaviour similar to a normal slalom sail, largely due to the full batten/square top geometry. It was very fast at the bottom end of the wind range, but never really 'locked in' when maxed out - it had a kind of spongy feel that in turn created board control issues. IMO this was because it had considerably less skin tension than a normal WS slalom sail that typically rigs with over 100 kg of downhaul tension - this probably would not be an issue for you.

Having said that, I imagine the A cat sails are light years ahead of that by now. 

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The main for my cat has subtly little shape, only maybe 10mm luff curve (that's from memory, I designed it 20 years ago). It's a 30' cat and is hoisted on a 500mm *125mm wing mast that, as with your's, does not bend F&A. Shapewise the sail still looks good, mold wise it looks like something out of Waterworld, but that's another story. ^_^

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Here's the late lamented Sid's conventional single skin, flat main and 500mm chord mast. Sid got really smashed into pieces in a recent blow - but could be rebuilt - if I was completely bonkers. Beam, main hull, one float and mast all in many pieces. RIP Sid.

sid'smastsail.jpg

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On 3/22/2018 at 4:46 AM, Groucho Marx said:

No, that's including the mast - which weighs including running and standing rigging 26 kgs.

Height is 8.83 metres, including bearing and the section is 200 x 240mm.

Staggering. 

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Excuses, been drinking Cassels beer  ...  and nothing to do with Frog (maybe there is) but just a wonderful image of multihull sailing? Looking at double rig, maybe a Melanesian proa. Any experts here know?

outrigger.jpg

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Windward and leeward sides of bodgied up ex-Cox's Bay Skimmer's two separate mains to create single double main for Frog. Boat went okay this morning but that will be the last with make-do sail; next will be with full sized new Bill Barry main.

frogmain2.jpg

frogmain.jpg

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Nick Atkinson took this shot of Frog sailing past his traditional Mullet Boat moored at mouth of Motions Creek. Sail looks close to ridiculous but still moved boat okay.

FrogbyNickA.jpg

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Bump?

Frog, like the frightened mother hen, survived the recent savage cyclone winds of 110 plus knots at Manukau Heads. Didn't sleep well that night but Frog moored in close to the point survived unscathed. But Auckland and rest of the country has been smashed, trees down everywhere.

frightenedchook copy.jpg

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About time you had some luck. 

Nice one. :)

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yeah... good news for all.....  We have been seeing some crazy weather this year.....  Today in Sydney will top out at 35 degrees C when it should be more like 22 degrees C.....

the seasons looked to have shifted by 6 weeks later in the year !  Very warm ocean currents still off NSW.

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18 hours ago, xsailmakerSYD said:

yeah... good news for all.....  We have been seeing some crazy weather this year.....  Today in Sydney will top out at 35 degrees C when it should be more like 22 degrees C.....

the seasons looked to have shifted by 6 weeks later in the year !  Very warm ocean currents still off NSW.

same here in southern brasil. we should be seeing temperatures in the low to mid 20s (in°C). and it's in the low to mid 30s instead.

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Couple of 1990 shots of my old trifoiler Misguided Angel; the only time my better half set her posterior on the thing; Jim Keogh helming. Frog is just a smaller, more developed version of the Angel.

heatherJimMA3.jpg

MAstern24.jpg

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