International AC 62RC Class

D4Z /AC 55RC--proto for AC 62RC

Here are the final specs of the very experimental main foil and rudder foil. The illustration below shows one half the main foil plus the iFlap. Each rudder foil will be the same size as one half the mainfoil-no iFlap. The main foil is twisted 3 degrees from the center to the tip. The rudder foil is not twisted but droops 10 degrees. Daggerboard extends below mainfoil, as does the rudder foil.
1) D4Z
a. design weight=9.17lb(boat plus Trapeze Power Ballast System but no ballast)
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b. sail area =1825sq.in.
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c. main foils carry 85% of the weight* for light air takeoff. (this will change if the ballast system is removed or if ballast is added)
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d. each mainfoil carries 3.9lb
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e. Sq.in. SA per lb. incl. ballast system but no ballast=199sq.in per lb all up weight.
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f. Sq.in.SA per lb. w/o ballast system= 243 sq.in.per lb all up weight.
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2) Mainfoil
a. projected span=15"/16.37" including tips.
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b. actual span=16.5"/17.87" including tips.
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c. Projected foil area=22.5sq.in. (area of vertical lift-including tips)
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d. Actual area about 24.6 sq.in.(including tips)
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e. foil loading=.173lb/sq.in.(based on 3.9lb per mainfoil/ actual loading is slightly less because this is based on projected area)
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f. Designed load is for 85% of a boat weight of 9.79lb which includes the Trapeze Power Ballast System with no ballast. Sailing weight w/o the ballast system=7.52lb.
85% of 9.79=7.79; each foil supports about 3.9lbs.
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g. Aspect Ratio=12.98/1
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3) Rudder foil(one of two)
a. span= 8.18"
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b. Area=11.25 sq.in.
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c. Aspect ratio=6/1(geometric with just lifting portion of foil-because of radius effective aspect ratio is about 12.8/1)
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d. foil loading at 9.17lb displacement=.061lb/sq.in.
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e. anhedral(droop) 10 degrees.
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Ilustration shows iFlap on tips which I will probably use. The idea is high lift at low speed then as speed increases flaps are exposed reducing drag.

 

Here is a shot of the quickie mold for the experimental mainfoils on the D4Z/AC 55RC.
The mold includes iFlaps* at each tip.

For more on what an iFlap is go to: http://www.boatdesign.net/forums/mu...f-righting-trimaran-test-model-36058-105.html post 1561

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AC 55RC(D4Z)-the "AC45" of the AC 62RC Class

Go here to read more about the first carbon "Curved Twisted Surface Piercing T-foil" : http://www.boatdesign.net/forums/mu...trimaran-test-model-36058-125.html#post716211
Pictures of #2 up-same place----

here are a couple of shots-

 

D4Z / AC 55RC foils roughed in and almost ready to assemble:

UPDATE-12/19/14- the mainfoils for the cat have been assembled-see here: http://www.boatdesign.net/forums/mu...trimaran-test-model-36058-126.html#post717858
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International AC 62RC Class / AC 55RC Proto Class

Major decision last night: moving the rig 3" forward. When I originally designed the D4Z, it was not designed as a foiler so the daggerboard trunks are too far aft . I was going to try to make it work but I came to my senses and put the rig fairly close to the same position as on my other foilers which means the mast is stepped 3" forward of the forward crossarm. It allows the foil "footprint" to be longer which will improve pitch control. I'm a bit concerned about the new experimental foils with this because they have a larger than "normal" lateral resistance component in addition to the extended daggerboard-so I'll just have to test it to see how well it works. Everything can be adjusted with my favorite grinder(!) should the need arise.
I've posted new and old working sail plans so you can see the difference.

 

International AC 62RC Class / AC 55RC Proto Class

Seasons Greetings, Merry Christmas and Happy New Year to all of you!

 

D4Z /AC 62RC Prototype

Some shots of the foils temporarily in place-they'll go about 6" higher. Also, the radio box is shown between the hulls:
More detail here: http://www.rcgroups.com/forums/showthread.php?t=2180752&page=36

 

International AC 62RC Class / AC 55RC Proto Class

One of the guys that had been working on an AC 55RC has switched and started building an AC 62RC. More can be found here:
http://www.rcgroups.com/forums/showthread.php?t=2180752&page=38 See posts 551 and 556.

 

Here is a shot of the first International AC 62RC nearing completion in Australia:
UPDATE-new picture-weight4.8kg(10.56lb)
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D4Z / AC 55RC-the "AC45" of the AC 62RC Class

Progress on the D4Z-painted today. Radio and rigging next.

click for best view:

 

D4Z /AC 62RC Prototype

More D4Z pictures and her new stand:
click-

 

D4Z Sails

Got the sails for the new cat. Made from Dimension Polyant 2.2 oz ODL(one-design laminate) The rig is reefable by rolling up the foot and there are two sizes of jib. The top of the main is a Wing Tip for masthead buoyancy and aerodynamic improvement.
The gooseneck/vang or "vanganeck" is a new type of vang that allows the main to be very low with the foot sealed by an endplate.

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Foiling AC55 RC

 

AC 62 is Out for 2017

Startling news tonight: the AC 62 will not be the America's Cup Class for 2017!
Read more under "Multihulls" in the "35th Americas Cup: Foiling Multihulls" thread.
One things for sure the America's Cup RC Project will continue-when we know what the next boat is I will ask Jeff to change the title of this thread or we'll start a new thread which might be a better idea since there is a lot of AC 62RC specific stuff in this thread.

 

ACRC Cat

Anybody interested in the Radio Controlled AC Cat is invited to make suggestions for the new boat. There are some things we know now: if they go with a 45 we won't go with a 45" model. We won't go with a boat designed and built under the Mini 40 or F48 rules though such a boat may be able to be converted to the new class. Two AC 55RC cats already exist. They were conceived of as "the AC 45 of the AC62RC class" and may wind up being THE AC RC class.
I'd like to hear anyones opinion. My enthusiasm has waned just a bit, but the fact remains we will have a Radio Controlled Foiling America's Cup Cat-and that is a great opportunity for anyone interested in technically sophisticated RC models. The same characteristics will be insisted upon: the boat will foil upwind, the boat will be able to gybe on foils. And tacking on foils is a target that may come with skill in sailing the new boat. Movable Ballast will be legal-the reason is that it can double the righting moment of the boat. Wings will be one design but, for a time, soft sails will be legal with an area restriction equivalent to the wing. Depending on the discussions we are having now, foil systems may or may not be one design. The idea is to allow new people to participate w/o having to be a foil or wing expert. Same with movable ballast systems.
The idea never has been to copy the full size boat but to develop a high performance RC cat worthy of being an America's Cup Class.
Speak and be heard or not.......