Radio Controlled Foiling America's Cup Catamaran

Since the rules were just so dramatically changed for the full size boats AND since two of us have already built boats(as AC 55's from the previous thread) I wanted to come up with basic Rules that would be as close to the new rules as possible while allowing the two completed boats to be immediately legal. John Xman suggested length and beam done to a 1/10th scale. That worked well allowing the two completed boats to closely fit while maintaining the proportions of the newfull size boats.
AC4.8RC:
Length: 4.8'=57.625" (rounded)
Beam: 2.78'=33.375" (rounded)
Tentative rules based on my D4Z:
--movable ballast system legal and may exceed maximum beam-no restrictions,
-- foils may extend outside the maximum beam.
--rudders may be transom hung
--SA up to 1900sq"
--no channel restrictions
--no foil type restrictions
--no rig restrictions
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As far as I'm concerned that is the Basic set of rules until more boats are built and an excellent foiling system or systems are developed and proven.
-No boat built under these basic rules may later be disqualified or modified in any way by later rule changes.
My primary direction now will be to complete and foil my boat with three different foiling systems as well as experiment with the Trapeze Power Ballast System. I would imagine Jim in Australia will be doing similar development .
The idea and absolute requirement for a successful RC Americas Cup foiling cat is:
1-that it foils in light air,
2-that it foils upwind,
3-that it routinely gybes on foils,
4-that it is capable of sailing a triangular or windward/leeward course faster than any comparable size monohull.
These will be tough requirements to meet but are essential for future growth of the class.
The D4Z below is one of the first two AC4.8RC cats and is nearly complete and will be under constant development. Jim in Australia's prototype is under development but is sailing and has foiled for short bursts.
D4Z Trapeze Power Ballast System 3-21-15 009.jpg
D4Z main and rudder foils ready to fly 010.jpg
 
AC 4.8RC---D4Z

AC 4.8RC---D4Z

My D4Z is nearly complete- just have to run the lines to the winches. The boat uses two RMG 280's for sheets, one 280 for F&A "Trapeze Power Ballast System" and an RMG 380 for side to side ballast system(white box aft of forward crossarm).

D4Z radio box finished-4-29-15 003.jpg
D4Z Mast Step 5-4-15 001.jpg
D4Z Mast Step 5-4-15 006.jpg
D4Z Main 3-2-15 001.jpg
 
winches corrected

winches corrected

The boat uses one RMG 280 for sheets, one 280 for F&A ballast and one RMG380 for S-to-S ballast......
 
D4Z, an AC 4.8RC America's Cup Cat

D4Z, an AC 4.8RC America's Cup Cat

Did a rig test this morning-all was good-nearly ready to sail after some work on the stand:
D4Z first test rig-5-13-15 002.jpg
D4Z first test rig-5-13-15 009.jpg
D4Z first test rig-5-13-15 014.jpg
D4Z first test rig-5-13-15 001.jpg
D4Z first test rig-5-13-15 019.jpg
 
D4Z-AC 4.8 Foiling Cat--Foils

D4Z-AC 4.8 Foiling Cat--Foils

D4Z with very experimental batfoils in place. The batfoils are surface piercing T-foils twisted from 0 degrees at center to +3 degrees at the tips. Each main foil also has an intrinsic 15 degree flap(iFlap) on each tip(whose area may be reduced in testing). The idea is to have low speed takeoff and reduced drag at higher speed. Because each main foil is canted bottom out 10 degrees it only requires a 4 degree angle of heel for the boat to fly the windward main foil, reducing drag a lot automatically.
D4Z Foils  5-14-15 007.jpg
D4Z Foils  5-14-15 006.jpg
D4Z Foils  5-14-15 002.jpg
D4Z Foils  5-14-15 011.jpg
 
D4Z, an AC 4.8RC America's Cup Cat

D4Z, an AC 4.8RC America's Cup Cat

Testing delay due to illness and family crisis with my crew-no testing until both are resolved.
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More D4Z Foils(Batfoils) :

2cz7zbb.jpg
 
D4Z First Sail-max 2mph!

D4Z First Sail-max 2mph!

I finally got the conditions I wanted for the first test sail. Unfortunately, over 2hours the wind never picked up......

24zb2uh.jpg
 
AC 4.8RC

AC 4.8RC

Foiling soon I hope.
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The "new" version of the fullsize AC rule(June 2015 ,version 1.2) states that maximum length is 49.2'(15m). Do we change the RC rule again??!! Current RC rule as of 8/18/15 is here(and tentative) : http://www.rcgroups.com/forums/showthread.php?t=2384452
The rule posted in the first post of this thread has been changed.



Full Size rule released June 2015---- https://docs.google.com/viewer?a=v&...vbXxub3RpY2Vib2FyZHxneDo2ZWMxMzBkODUyNDJiMzY5
 
Hi Doug,
i feel it's not helpful to change anytime the roules for RC multihull classes.
We have all what we need...
Mini 40 and 2m class which is open also for smaller ones.
If we get minimum 5 equel boatssizes in one class they can get easy a own classrating.

Regards

Rene
 
AC 4.8RC

AC 4.8RC

Thanks, Rene. I feel that "we" have a golden opportunity to take advantage of the full size AC being sailed in cats. I think it is very important to have a dedicated America's Cup class of RC catamarans. But it will be very difficult to meet the criteria in the first post of this thread, but doing so will ensure the success of the AC 4.8RC.
 

mij

User
As Doug says, getting a rc cat foiling reliably around a course is going to be challenging. I don't think that we should get too hung up on exact lengths yet. The few of u actually working on this class of boat are pretty thinly distributed across the globe, so I don't see there being any regattas in the near future.

I'm currently working on a new boat, but below is the boat I've had the most success with to date:


 
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