Fire Arrow Foiling Trimaran Test Model - Page 14 - RC Groups
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Nov 10, 2017, 07:31 PM
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DLord's Avatar

Gitana / Fire Arrow


Quote:
Originally Posted by davidjensen
The foil cross sections must be quite different.
========================
They're somewhat different alright(FA foils thinner) but the shape of the foil viewed from forward or aft is remarkably similar.Both are designed to work like the TNZ foils in 2012/13 that had automatic altitude control. Fire Arrow was the first trimaran of any size to use the "uptip" type of ama foil. The droop tip on Fire Arrows foils was to provide more vertical lift while retaining the functionality of the TNZ type of foil.
David, what did you think of WOLF?




Look closely at the "droop tip" on both Gitanas UptiP ama foils



Last edited by DLord; Nov 11, 2017 at 08:45 AM.
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Nov 11, 2017, 01:44 PM
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As anyone who has read this thread will know one of the great advantages of the Fire Arrow Foil System and the nearly identical systems on Maserati, Gitana 17 and Banque Populaire is that the mainfoil can develop downforce-a point I've been making about the Fire Arrow for years.
Read Mr. Gabart's comments below-he's obviously been thinking a lot about a mainfoil that can develop downforce--very cool!!


Macif /  Gabart on  DOWNFORCE--from on board Macif as she races around the world:     

In François Gabart 10 nov. message :
"You have to find the balance to be able to stay in support on the central hull, but it's not so easy when you go fast. I cannot stay on the central hull all the time and I'm still not comfortable sleeping like that. It's starting to come, it will take training again. But my sleep is damaged, despite fatigue. I still managed to take a few naps."

Is it not in this case that a foil on central daggerboard, when adjusted to provide a small downforce, which can add passive safety when the singlehander is sleeping ? In case of gust of wind with a move to more heel, the inflow incidence on this foil increase instantly and can provide an extra RM which adds to the one due to the weight. And moreover in steady state condition, this foil RM component is in squared speed boat, can increase in parallel with heeling moment in squared apparent wind speed. I am right ?"

Yes, you are right! dl
     
Last edited by DLord; Nov 11, 2017 at 01:49 PM.
Nov 11, 2017, 02:39 PM
Will fly for food
davidjensen's Avatar
I would love to see this in action at the RC scale.
Nov 11, 2017, 04:09 PM
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Fire Arrow


On the Fire Arrow it works automatically and in early testing when she was overpowered the foil downforce prevented capsize.
The F3 used downforce from the windward foil to stay upright. It's a well proven concept fullsize and at RC scale.........




Last edited by DLord; Nov 11, 2017 at 04:15 PM.
Nov 11, 2017, 07:54 PM
Will fly for food
davidjensen's Avatar
Still would love to see it.
Nov 12, 2017, 07:29 PM
Thomas Armstrong
Still would love o see it - recent pictures, or better: recent video.
Can you give the boat to someone that can sail it?
Nov 13, 2017, 07:28 PM
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DLord's Avatar

Gitana trouble


From the Gitana site after she lost the Transat to Sodebo:

"On this her first trial run in race configuration and up against particularly stiff competition, the Transat Jacques Vabre has certainly lived up to expectations. The high standard of play pushed Sébastien Josse and Thomas Rouxel to their limits and has given them a better understanding of the fabulous machine that is the Maxi Edmond de Rothschild. Some technical incidents on the second day of racing, did however prevent the duo from expressing the true potential of Gitana 17 by forcing them to do battle without all their weapons. Indeed, in addition to the AIS black-out from the start, which could have had disastrous consequences in terms of the sailors' safety, the duo had to deal with repeated engine failure; damage which cost the skipper of Edmond de Rothschild many long hours in the bilges, whilst his co-skipper busied himself with maintaining the rhythm at over 30 knots. Last but not least, it's an injured bird', deprived of her wings', which has just pulled alongside in the Marina in Salvador de Bahia. Indeed, on Tuesday, after the front rolled through, the sailor from Nice informed his shore crew of serious damage to the boat's port foil. Unusable, the precious appendage was raised to avoid any further damage. Two days later, it was the turn of the starboard foil to show the same signs of damage as its twin. To put it plainly, our duo was deprived of her major assets for ¾ of the race, which explains the speed deficit everyone observed."
Nov 13, 2017, 07:32 PM
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Fire Arrow Foil System / WOLF


Quote:
Originally Posted by tarmstro
Still would love o see it - recent pictures, or better: recent video.
Can you give the boat to someone that can sail it?
==============
She may be sailed for the last time next year. The priority is to get a fullsize version built.
Nov 19, 2017, 08:15 PM
Registered User
@DLord,
excellent project

I try to build rc moth.
https://en.wikipedia.org/wiki/Moth_%28dinghy%29

some images from Bing

https://www.ecplaza.net/offers/aqua-...-water_4001055

since I plan to build ultralight moth, my project is based on
Aqua skipper,Water Bird,Water Vehicle,Aquaskipper,Waterbird,Pumpabike,Water Scooter,Sea Scooter (different name for the same)

https://www.bing.com/images/search?q...pper&FORM=IGRE