Spinnakers for rc sailboats are few and far between mainly because the recognized AMYA and most development class rules prohibit them or tie them down with unrealistic spinnaker pole requirements. The exceptions are the 36/600 Class,the Formula 100 Class and the new 3 Rater Class each of which allow spinnakers with no artificial pole restricions and no area limitations.
I’ve designed several rc spinnaker boats and have had about 8 years experience sailing/racing on a regular basis with these sails on rc sailboats. They add a new dimension downwind-mandating tackng downwind in many conditions where a “normal” spinnaker-less boat would sail a more or less straight course.Using the Hoyt-Lord spinnaker system allows the spinnaker to be carried as high as a beam reach ; allows gybing at will ;allows a set in about two seconds and a douse in about 2.5 seconds. You can find sketches of this system under “innovations” on microsail.com. Though the system is patented I make it practice to encourage individuals to use the system free of charge if they would like to. At least two boats are being built now to use this spinnaker system-one in Germany and one in Australia.
It is a simple ,robust system that is loads of fun to sail but especially race with.
The beauty it adds to any race course is unparalleled: a fleet of 4 spinnaker boats rounding the windward mark at nearly the same time and popping multicolored spinnakers is an awesome sight to behold!!
Note: see some more spinnaker discussion under the “CBTF-canting ballast without the ballast” thread in this section.
UPDATE: 12/2/03: title changed from Spinnakers! to RC Spinnakers
Doug Lord microsail.com monofoiler.com
High Technology Sailing/Racing
Interesting question! Rumor has it(albeit from a VERY knowledgeable source) that part of the reason the Marblehead or 10 Rater(forget which he said) don’t have spinnakers now is that someone had developed a working Code Zero; of course a CodeZero is an upwind light air spinnaker/genoa that was used to good effect in the Volvo 60 class(fullsize).
In models the only classes that allow spinnakers are the A Class,the AC class the 36/600 class, the new 3 Rater Class and the new Formula 100 class.None of these rules makes reference to WHEN(as far as I know) the sail may be used.Most of these classes allow unlimited sail area in the spin. The A class, to some extent, and the AC class for sure put unrealistic(taken from big boat practice) restrictions on the spinnaker pole making carrying the spinnaker in those classes as high as a beam reach nearly impossible so far.
But in the other classes anything goes : symetrical or asymetrical, Code Zero etc. The value of doubling the upwind sail area on a 36/600 or on an F100 would be negligible EXCEPT in VERY light air, I think. The Code Zero type sail in either class would be a real hassle simply because of the sheet eating winch required to gybe an asymetrical or tack the “code zero” as the case may be. Probably a sort of self regulating rule until ultra miniature super powerful winches show up…
This “rumor” has been repeated for close to a year now and has never been backed up. The people currently in charge of the international classes who write the rules have never heard this story. General understanding is that the spinnaker provisions were removed from both the M and 10R class rules a number of years ago as part of a general major rule update and that the spinnaker provisions were removed as a holdover from the old vane rules and because virtually no one anywhere was using a spinnaker. Either the alleged “source” should come forward or the tale should stop being told.
The source of the story asked for my word that I would not reveal his identity ; I have honored his request for several years and will continue to do so. I believe his story but, at any rate, it is water under the bridge.
From a development standpoint the aforementioned classes made a humongus change to their class rules when they removed the spinnaker: they reduced potential sail area by 50% or more; hardly a minor tightening of the rules. It(the rule change) ,in my opinion, violates the spirit of both classes put forward by their founders who made the spinnaker legal. It is a profound illustration that new ,forming, classes should look closely at: when the class rules are left up to a variable democracy in a development class instead of being locked in stone from day one like some newer class rules then this kind of “backwards” move by a class can occur. Nobody who voted in either class wanted to go thru the expense or development hassle of a spinnaker(or the defeat possible if someone made a spinnaker work in either class); so what to do, what to do: get a bunch of your closest friends together and change the rule so NOBODY can use a spinnaker–it didn’t happen exactly that way but, as I understand it, a minority of owners(not of voters) in both classes passed this change to the rules.But regardless of why and how many voted for the rule change it was passed ; the real tragedy was that it COULD be done at all! After 50 years of being legal! Against the express wishes of the founders of the classes!New development classes beware: lock in your rules so that under no circumstances can they be changed except by an overwhelming number of the owners of the class!!!Make “basic” rules untouchable!
For the life of me I can’t understand why the two premier development classs after being around for 50 years would all of a sudden decide to eliminate the spinnaker!!! Why all of a sudden? Maybe somebody somewhere WAS getting close, maybe not–I believe my source and the logic(or illogic) of what actualy happened tends to make me believe it even more.
The fact is that if a working spinnaker of any type was made to work in either class the cost for a competitive boat ASSUMING the spinnaker was competitive would go up $300 or so. And every boat w/o one would be obsolete–the price of development and less than 10% of the cost of either boat bought complete ready to sail…Nevertheless could be heavy motivation to screw with the 50 year old rules that were, coincidently(?) changed just a few years ago…
[-crzwom] Gee Darryl: this was no conspiracy-just a bunch of guys trying to save money-and maybe stave off any embarrasment that might result IF someone made the sail work competitively.
Of course, the cost conciousness came at great expense to the noble traditions of each class–but anything to save money, right?
[:-jump]
Note: more discussion on spinnakers under the “CBTF-canting ballast without the ballast” thread.
For those contemplating a spinnaker here is some history and detail. Garry Hoyt inspired the Hoyt-Lord System(HLS) with his design on the old Freedom boats of a spinnaker pole pivoted in the middle then slid to one side for storage.
When I looked closesly at some of the rules in existence 10 years ago it was apparent that working within those rules you would only be able to carry a spinnaker about 20 degrees either side of dead downwind. I considered that unacceptable particulary for models since the wind can be so fluky at so many different venues. So I worked on the idea of a system that would be able to be carried like a fullsize spinnaker: from (at least) a beam reach to a beam reach; instantly gybable.(90 degrees above dead downwind on both gybes)
What I came up with is a system that uses two poles each mounted on the centerline at the forward most point of the boat. They are trimmed using a relatively small servo with 180 degrees of travel. A 3003 Futaba works on a 50" boat; a 3801 works on a 65" boat.
The spinnaker trough(deck opening and stowage tube) opening in the deck was found to work best IN FRONT of the forestay.
On my spinnaker boat designs the emphasis has been on having a spinnaker that is usable in the widest range of conditions; that usually results in a fairly small(and high aspect ratio) sail compared to a masthead spinnaker but they can be carried from 3 to 20 plus MPH wind and still add 50 to 100% to sail area. Competition systems could be designed that allow up to three (or more)different sizes of spinnaker to be used but that gets expensive.
The basic system is quite simple with the most important “ingredient” being the inducement/removal of slack in the spinnaker downhaul. This is critical and effectively makes the downhaul 9-12"(on 50 to 65" boats) longer than the halyard so that when the spinnaker fills the downhaul does not produce a pucker in the sail. This is accomplished by having the winch maker make up a three winding path drum : two winding paths operate a continuous loop that moves a double set of blocks on deck exactly 1/2 the length of the spinnaker hoist.The third winding path pulls in on a line attached, on the back deck,to the spinnaker downhaul in such a way ,using a block, that as the sail is doused this third winding path pulls in on the line and removes slack from the downhaul. When the sail is set this third winding path turns the opposite direction INDUCING slack into the downhaul.
The spinnaker poles are set up with a spring that pulls them out automatically when the sail is set; thereafter they’re held in place by a combination of spring power and wind pressure. The sheets ,in this system, place no continuing loads on the trim winch which makes a relatively small trim servo possible. The front end of the spinnaker poles are also worth noting: they are based on an invention of Garry Hoyts(another one!): the Hoyt jib boom. The first two inches of each pole is made of stainless and is bent so that the SS end goes thru the deck. The SS acts like a vang that makes the poles hold their position and not swing up under load from the sail.Thru experimentation I found that the spinnaker trough(opening in deck and tube under deck) should be around( no less than) 2.5" in diameter(.4–.5oz. spin material). The tube under deck is sealed from the inside of the boat and has a drain both at the front and the back end. This eliminates having to have a complicated cover for the deck opening. See the sketch at microsail.com under “innovations”.
I have also devised two forms of asymetrical spinnaker.The first type operates very much like a full size setup and requires a retractable bow pole; I used this system on a Melges 24 model 53" Loa with a 14" bow pole that completely retracted. This system is more complex and expensive-by double- than the HLS because in addition to requiring a Guyatt winch for the halyard it also requires one for spinnaker trim.And it requires a method of inducing and removing slack from EACH spinnaker sheet. On full size boats the asymetrical is simpler than a symetrical
system; not true for models except for the following system (and some possible new developments)that can only be used on una rigged boats: This system requires a retractable bow pole AND a sort of jib boom. The front end of the jib boom is done just like a Hoyt jib boom; the back end curves up and has an integral line run from the curved end to the spinnaker halyard/mast intersection. The boom is done this way to avoid snags.
When the sail is set the clew is attached to the back end of the boom like a jib; the tack to the front end of the pole(a spring pulls the pole out along with the spinnaker tack). The jib boom is sheeted using the same winch used for the mainsail. Takes a while to work out the trim ratio’s but once set up you have an asymetrical that can be carried higher than a beam reach and gybed at will while using only one Guyatt and no other servos(except the mainsheet servo you would need anyway)…
e-mail me with any questions: lorsail@webtv.net
I have been contemplating something along the lines of a code 0 asymmetrical spinnaker for an F48 project that I have had on my drafting table for over a year now (Dick L. - I promise that I will build it someday).
Basically the rig for the boat is a unstayed wing mast. The Code 0 would be used in light wind as an upwind sail (when the wing sail would suffer due to reynolds number effects) and in stronder winds as a downwind sail.
Because the wing mast is unstayed, there is no forestay to have to get the sail around during a gybe thus reducing the overall size of the trimming winch.
I am contemplating a system with a roller furler that would allow me to douse the sail by rolling it around an airfoil shaped headstay. Since the headstay would be the luff of the sail you would not need to gybe the sail around it. the main issue with that system is that you would have a relatively draggy furled sail forestay to carry around upwind. So I have devised a scheme where the headfoil would be hoisted to the top of the mast just before rounding the windward mark and then “unfurled” as you round the mark. when not in use, the headfoil and furled sail would lay diagonally from the bow to the back corner of the boat.
The system would be removable (since the F48 rules only allow spinnakers for exhibition). but since there are no other boats in my area to race against, I would probably use this sail most of the time when I was out sailing for fun.
On the F3(and X3 probably) hydrofoil an optional asymetrical spinnaker is offered. It uses a manually added bow pole along with a much longer version of the Hoyt jib boom to allow the spin to be TACKABLE as well as gybable-works good and permits speed reaching without having to lug around an extra winch or two; sheeting is tied in to the main.Jib is removed and spinnaker added on the beach; sails upwind when required…
In addition to the cross references noted in the original post in this thread see the discussion under:"the America One " thread under New Classes on this site.
Matthew, the snuffer surely could be used but is illegal in the F48 class and too heavy in the multiONE class-for now. A problem arises when you start to use an asymetric on a boat with main and jib: you need two Guyatts one to set/douse and one to trim. It might be possible to adapt my symetrical system but it might not
work too well. Asymetrics on models are generally twice as heavy and twice as costly as a symetric for the above reasons. My foilers are offered with hand attachable asy spins that are sheeted from a large(long) version of the Hoyt jib boom so they can be tied into the mainsheet winch; the jib is removed ,the spin attached and away you go–good for blast reaching!
Sorry about my phrasing: spinnakers are illegal in the mini 40 class for racing and EFFECTIVELY illegal in the F48 class for racing. Dick must be right but I don’t remember that provision…
The snuffer system is very similar to what I have been contemplating. If you are on a trimaran, the snuffer tube would be installed inside the hull (like Doug has done on his Spin 50 and America One boats).
Doug is right that the asymetricals require two big (heavy) winches. There is a lot of sheet to wind in/out. But with an unstayed mast with no Jib, the sheeting gets a lot better - to the point where more resonable winching systems become practical - It is even possible to think of an arm winch system.
I have read the F48 rules as Dick has - that a spinnaker would count as sail area. And since the sail area is limited to 1392 sq. in. if you use a spinnaker, the combination of the spin and main must be less than 1392 sq. in. Thus, the main would be very small by itself and you would pay a big penalty around the course.
It would be interesting to “define” some F48 races / regattas as “speed trials” in the SIs in such a way that spinnakers would be legal. I don’t see why a speed trail has to be limited to a reach on a single tack. Why couldn’t a speed trial consist of a windward leeward course, twice around with a start and finish line?
See rule D. SAIL (s) #3. “Spinnakers may be used only during one way speed trials…”
“…no limit to spin size shape or area”
UPDATE: it appears there are at least one or two major loopholes in the F48 rules.These may or may not be addressed by a technical committee-contact Dick for more info.
It appears that you can carry a sail that looks and acts like a spin ,say a screacher, as long as the area comes out of te legal 1394 sq. in.; at first second or twentieth glance (at least to me) this appeared to effectively rule out a spin BUT sails of any type or design are also allowed so for rough conditions it might prove beneficial to carry a main or main +jib and spinnaker ,I mean screacher as long as the total area was kept at the legal limit…
Doug Lord microsail.com monofoiler.com
High Technology Sailing/Racing
A asymetric kite would help stability downwind anyway, a fullsize cat with a kite is less likely to dig in the leward bow, so in small rig conditions a kite would allow you to sail faster and lower, while keeping inside the sail area rule. Could you ditch the un-used winches when you change to the top rig for light weather tho? Lot of fiddling about but it would be sooo quick in heavy weather!
