International AC 62RC Class

[Doug Lord]

International AC 62RC Class

The reason for 62.3" /1.58m is because the model is semi-scale at 1"=1'. There would be a lot of resistance over here to making the thing bigger. Are there any shipping restrictions on 2m models that make it excessively costly to ship?
I think this class should be built to stand alone-not be part of any other class. There is no problem with foiling at 1.58m-trust me. My F3 foiled extremely well using wands 15 years ago at a length of 56" and beam of 72".

 

[Doug Lord]

International AC 62RC Class Rules

International AC 62RC Class Rules

Chris, another thing just occurred to me about the 2m class and the AC 62RC: in an open rule class like that a tri is bound to be the fastest-isn't that true? The AC 62RC
foiling and using a Trapeze Power Ballast System might give them a run for their money. But the AC 62RC is highly likely to be beaten by a well designed 2m trimaran foiler. What do you think?

 

[Doug Lord]

International AC 62RC Class

Some thoughts in response to a comment on rc groups:

I think the rules can be a box rule with some one design components like maybe the rig(Wing-I'm leaning toward leaving a soft sail rig open within the max sail area rule), the foils and the foil control system. My reasoning is that there aren't too many people around that have the skill to design foils or a foil control system or a solid wing.
By making these items one design it may ensure that more people will be interested because they don't have to worry about these components.
--
I think hull design and beam design can be open within the minimum weight rule.
--
The first priority for the class is to get a working prototype that will:
a. foil in a 5mph breeze or less( idea-class races restricted to races where the boats can foil?)
-
b. foil upwind and downwind,
-
c. the goal should be to have the boat able to tack and gybe on foils. This will be a combination of design and skipper skill. The prototype will determine if this is realistic or not.
==============================
While I am modifying a D4Z platform to serve as a prototype to prove the foil system, there is no reason at all why anybody else that wants to cannot go ahead with their own prototype at the same length as mine (51.5") or 48" or 62.3".
I will share all the technical stuff I have. No one should underestimate the difficulty of doing this-it has never been done before. But I'm completely confident that it can be done-mainly because of my successful application of UptiP foils to my Fire Arrow trimaran.
What we will wind up with is the first America's Cup Class RC catamaran which will be a showcase of modern technology. It will not be "cheap" to do this well, but it shouldn't be outlandishly expensive for what it is.. It will be fun to sail, I mean fly, and it should be very, very fast. It will take practice to learn to race well, but that's the fun part.
==========
I've written to Ian Holt, who has done some excellent RC foiler work, to see if he would join the discussion on rc groups(linked earlier).
Do any of you guys know any of the French or British RC multihullers? Could you extend an invitation to them to join in the discussion?

 

[Le concombre masqué]

How many more boat classes ?...

 

[Doug Lord]

International AC 62RC Class

This would be a very unique class. Throughout the history of radio controlled sailboats the America's Cup has always been a draw for people who love sailing and love the pinnacle of the sport that the America's Cup is. You can find "AC" or 12 meter models all over the US and probably everywhere else.
But there is one HUGE difference: those classes are all monohull. Never in the history of radio control have multihull aficionado's had the opportunity we have now to create the first America's Cup Class RC catamaran!! This is an opportunity to draw more people into the sport, to show what multihull technology is capable of in an RC application as well as to have incredible racing and breathtaking fun flying these boats. It is something we can do together now that we finally have a golden opportunity like this-think about it: an America's Cup Class 62RC catamaran!

So the answer to your question is one-for now.......

AC 62 renders from Andrew Mason/Virtac:

 

[egi1610]

Doug,
there is in my opinion no need for a new sailing class multihull aslong as the current two (2m, and Min40) are not yet really 'flying'
I mean this in two meanings: a) we have not yet a rush to these classes, Mini40 would be smaller and thus easier for transport than your proposed design and still at our biggest event in Lake Brombach we were never above 12 boats in the race b) both classes experiment with foils, I see it absolutely bad to force to a onedesign even with fixing the foils? You would kill invention!

I would/do support you to setup a model that works, races well and can participate in either 2M or Mini40 (you would have to decide which one to pick)
and can be bought at reasonable prices, this might be good for the classes to attract more people that don't want or can not build but still want to race!

I would also like to propose (sorry for my ignorance but I think its time to say this) to go to measures in standard science: the measure system is SI (Standard International) the measure of length is there meter, the measure of force Newton...) I hate to say but I can not except a build with an odd measure like 1.56m... this is going against my feeling of harmony. I do understand your feeling of harmony comes from a 1:10 ratio of a feet class, but I do hope that you also know by now that boats don't scale down linear and making them scale in proportions would fail as the linearity of Waterdensity is not given and linearity of Wind on surface aswell not...

So from my end I do respect your idea of creating a foiler alrounder RC sail multihull but I am not in support to make this a new class and onedesign...
I like the 2M class as it allows for more weight, more crazy ideas than Mini40. I do understand the limits of transportation but if that is a limit to you then just don't sail that class. Mini40 is certainly after some experience and iteration foilable and we will soon see designs that support it (we have hydroptere actually do it, but not yet consistantly around a round course)

Eric

 

[Doug Lord]

International AC 62RC Class

Thanks for your thoughts Eric! I'm posting a copy of your comments on the rcgroups thread.

 

[Doug Lord]

International AC 62RC Class

This is a summary of the basic foil systems available to use on the AC 62RC with costs based on the D4Z/AC 62 prototype. Shouldn't be much more on the 62 since these linear servos and winches are overkill on the smaller boat. The Trapeze Power Ballast System for testing on the prototype will be the same exact version for use on the 62. Rob Guyatt(RMG Sailwinch) responded this morning about his winches capability to hold a load(when used for retract and deploy of the main foils) saying they do not have that capability now but he is building a new version that will-about 6 months before we know more.

I)UptiP foils-
A. Simplest is four foils in the water. While this may work it will be significantly slower than the Rake adjust or Fully Functional version, but will require no extra radio gear specifically to control the foils. It should do better than surface piercing foils upwind but probably not by much. And for best performance a Trapeze Power Ballast System should be used. Cost: $220 US for the winch and maybe $50 in material or less.
-----
B. Rake Adjust foils would be the same as "A" except that two Firelli linear servos will be required to adjust the foil rake. Cost: $140US. This version should be significantly faster than A, but will require[enable] the adjustment of the windward foil to neutral as necessary. This version would also require the Trapeze Power Ballast System for best performance. Cost $270US plus the linear servos, or $410US for performance related electronics.
-----
C. Fully functional UptiP foils require that the foil rake can be adjusted and that that either main foil can be retracted in one second. RMG winches will do this but the problem is that the foil in the water will be loading the winch, at least as best as I can tell. I wrote to Rob Guyatt tonight to see what suggestions he might have.
Assuming he can work that problem out the boat would require:
1- two Firelli linear servos for rake control, $140
2- two RMG winches for board retraction/ deployment. about $400
3-Trapeze Power Ballast System,as above about $270.
Total for winches directly related to a fully functional UptiP foil system=$800US
This would be unquestionably the fastest of all the versions, but after calculating the loads and adding this up even I was surprised. It would truly perform like the big boats but would have a fairly steep learning curve.
-----
II- Wand based T foils*- This would not require any radio control up to maybe 8mph(7knots) of wind. Then, because the boat is relatively narrow, a Trapeze Power Ballast system would be effective in getting the most out of the boat.
Dual independent wand systems are very effective in automatically generating RM IF the main foils are far enough apart. They wouldn't be on this boat.
So the movable ballast system would give substantial RM w/o taxing the foil system. Cost-$270 for the Trapeze Power Ballast System.
* would require a beam increase of about 6" for the foils.
=========================================
I haven't come to any conclusions but it looks like the "Fully Functional" UptiP foil system might be a step too far, but it would produce the most realistic and probably the fastest model.
The next in line would be either the Rake Adjust UptiP foils with a ballast system or the Wand based system with movable ballast.
The wand based system would ,unquestionably be the easiest to sail even with a ballast system. Look at the video I posted from Dario Valenza to see a wand based foiler with a "Trapeze Power Ballast System". I'm going to go find the video of the 18' Whisper using the same system and I'll post it with Darios video*.
* These videos are posted below.

 

[Doug Lord]

This is an A Class Cat foiling with a wand based system-found on Dario Valenzas blog:

https://www.youtube.com/embed/74YN7hPpuUM?wmode=opaque&start=0

 

[Doug Lord]

This video is the 18' two person Whisper cat using a wand based system:

https://www.youtube.com/embed/6AwfruS9aAo?wmode=opaque&start=0

 

[Doug Lord]

International AC 62RC Class

Eric, I'm sorry but I have to disagree with your thoughts on an America's Cup 62 Class. The America's Cup is special and deserves it's own RC Class, in my opinion. As I said earlier the America's Cup has spawned many RC classes, but only now has the chance presented itself to create an RC multihull AC class. I think it is a great opportunity-and I don't think incorporating this Class in an already existing class is a good idea.

 

[Doug Lord]

International AC 62RC Class

These are a series of principle's that should guide the rules and development of the AC 62 RC class . In my opinion, there can be no class until these basic principle's have been demonstrated.
A sort of Constitution of the AC 62RC Class----
--
I believe that the most important parameters for the new class should be, in order of priority:
--
1) A high performance hydrofoil sailboat that, as much as possible, replicates the foiling system used by the AC 62 Class, preferably using UptiP main foils in a three foil configuration like it's big sister. A high performance radio controlled hydrofoil sail boat that is designed as a racing boat, not as a development boat,
--
2) A high performance radio controlled hydrofoil sailboat that is capable of foiling upwind and downwind starting in as little as 5mph of wind,
--
3) A high performance radio controlled hydrofoil sailboat , that through skipper skill and boat design, can be capable of gybing while still on hydrofoils and where tacking on hydrofoils may be a developed skill.
--
4) A high performance hydrofoil sailboat capable of being sailed by experienced rc sailors or by experienced full size sailors with practice.
--
5) The design and rules for a boat as described in 1-4, should be done in a manner that facilitates the goals in 1-4 in the most cost effective manner.

 

[Doug Lord]

AC 62RC--LOA 51.2"(1.3m)

AC 62RC--LOA 51.2"(1.3m)

Some people on the rcgroups forum think the model should be smaller than 62", so how about 1.3m(51.19" Loa and .9m(35") Beam-max)? I feel that the boat should not be part of an existing class-it is an America's Cup Class model yacht and should stand on its own. But this is close enough to a mini 40 that the mods to be part of the new class are not significant. See the picture of the proto I am working on below.
I think the boat might be better off as an America's Cup Class 62.3" LOA(1" to the foot) , but I'm willing to consider this if a concensus can be reached.

 

[egi1610]

Doug,
Mini40 and 2M are developer classes. You can develop an AC like mutlihull in both 2M and Mini40 class.
Provided your offered ideas succeed, then don't you think it will soon be called the AC class when everybody tries to aim at flying multihulls?

I think your aim to make it an own class simply lies in the fact that you try to achieve exclusiveness.
Not something I think the multihull RC scenary accepts/acknowledges well...(at least I don't)

Nontheless, please proof in an existing class, that your racing ideas are on a round course (or up down, AC type of course) fast and faster than the other constructions and I am sure the 2M or Mini40 class will evolve into that direction The community here takes the races for challenge but more for exchange of ideas, to see what the individual builders thought about this or that. The evenings are full of discussion what ideas might add to performance and what not. A one design imho destroys that innovative thinking.

One design is OK for you and so far there is not really a commercial build on 2M or Mini40 widely adding to a lot more RC sailors, so feel free to sneak into that hole and fill it, if you believe it is worth it. I still heavily disagree to fit into a one design class, I want to build, I want to test ideas, I want to fail with concepts and finetune, evolve....


Eric

 

[Kampai26]

I agree fully to Eric. A OD class would be not interesting for me cause designing and building is the biggest portion of fun for me. Maybe we could make only some parts OD like the foils. These are really difficult to build accurately. Also we could then invest in real tools for them.

Chris

 

[Doug Lord]

The original idea was to make Wings one design like the full size rule does. Also, for the same reason the Wing(cost, access to the technology) is one design foils and foil control systems, and the movable ballast system would be one design..
Soft sail rigs would be legal with only area restrictions and the design of the hull and beams would be wide open.
The point of having just four systems one design was to ensure that people who wanted to race could do so without learning how design and build a wing, foils, foil control systems or a movable ballast system. The original class idea was to produce a race boat ,not a development boat, though hull and beam design and soft sails would be open(within area restrictions).

 

[Doug Lord]

International AC 62RC Class / AC 55RC Proto Class

International AC 62RC Class / AC 55RC Proto Class

John Xman has designed the first hull for the 62. He and a guy from Austria are building 62's now. Two of us are building smaller prototypes -55" including transom hung rudders. This will become the "AC 45" of the AC62RC class and any Mini 40 cat can be part of the "AC 55RC Proto Class" where the only rules are: a maximum length of 55" and the boat must be a cat- period. The idea is to test foils, wings and the Trapeze Power Ballast System at significantly less cost than doing it at 62".
Here are Johns renders-he can be contacted thru RC groups where the plans for his boat are posted:

 

[Doug Lord]

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

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

I've got the Trapeze Power Ballast System completed and ready for rigging. The radio box is complete, mast complete, sails ordered. Now I'm building foils with the first two very experimental mainfoils below.
These are some shots of the "Curved Twisted Surface Piercing T-foil" utilizing the iFlap(an intrinsic-molded in- 15 degree
flap-first tested on the Fire Arrow ama foils).
This particular foil shape was conceived of as a surface piercing T-foil utilizing the iFlap to create almost the same function as a wand controlled t-foil. The wand causes the flap to go max down for takeoff and when it reaches its designed flight altitude the wand neutralizes, reducing drag. Well, this foil should work the same way: the 15 degree intrinsic flaps produce high lift for takeoff but when the foil reaches its designed flight altitude the flaps are above the waters surface ,reducing drag.
The foil was first conceived for the Fire Arrow main foil to replace the wand controlled foil experimentally, but its first use will be on the D4Z cat where its simplicity is the greatest benefit-if it works well. It may easily allow the cat to fly the windward foils thereby allowing the D4Z to foil on only two foils. All that will be seen on video one way or another!
Projected area of these foils is 34.13 sq. in(220 sq.cm). The area of the two flaps is 25% of the total area.
The pictures below are just after pulling from the quickie mold-still needs final finishing/cosmetics:

 

[Road Runner]

Coole Sache Bitte weiter berichten, ich bin sehr gespannt

 

[multihull40]

Doug, i see the same bottlenecks as Chris and Eric, a increase of the existing classes will not help to bring the numbers of active sailors up...
But any idea is very welcome to develop the existing classes further plus PR to increase the interests on our activities...

Regards

Rene

GER 530
p.s. no idea what andreas is actual doing, still here present or busy with other things...