Will: Good luck in your experimentation. One word of caution. Boats are designed so that they float on their lines at a specific weight. Even minor changes in weight can have major performance effects on r/c boats. Taking a pound off the weight of a Venom would radically effect the hull as it would now be sitting way above the design waterline. You might think of talking to Bob Sterne the boat’s designer to get his opinion on what would happen.
Will, A problem with the Venom might be that this one of the only US1Ms that I know off that has the mast just about directly over the keel. Don’t know if this would cause problems for you or not. As you probably know, it’s more common that the mast be in front of the keel by at least 3/4" or so. If I were you, I would absolutely look into the Saber. To me this would make a better hull for what you are doing. Since you are planning to be running the hull at a lot of heal, then the best design would be the ORCO, but that would be a hard hull to work with in getting all your mods. in.
John,
Wow, really good looking work. I applaud you on going for this. Please understand that what I?m about to say is not a put down, but with all that stuff coming out the bottom of that hull, I think I might be able to take you with my Soling 1M. I just see SO much drag there! Being that I have done a good amount of experimenting with wings, I can tell you that any addition of drag is real killer with these RC boats.
I really would love to see success in these boats you all are building as I think new technologies is a very cool thing. I just have great doubts though that there will be success in racing these boats with any great success. Will has already mentioned in his few post above on this page 4 that there are some difficulties with putting the sticks of the TX just where they belong all the time.
I look at it this way. One would think that the simple addition of a jib trim would be a major advancement in sail trim. The full size boats certainly would never think of having their jib sheet and main sheet on the same winch would they. How slow would that be! But in RC sailing a separate jib trim does very little for performance as far as my experience goes. Yes, I am sure that some will disagree, but the fact is that I do not use one on my Star, mainly because it?s something that I seem to always have set wrong and I forget to reset it, and I win quite a few races with it.
But, great luck to you all, and I admire your skills! I sincerely hop to see you prove me wrong here. I look forward to seeing some sailing results from you boat John. THANKS FOR THE GREAT PHOTOS!
Greg et al, anyone who is seriously interested in the potential of CBTF can read the design reports posted in the articles section and under “New Classes”. Graham Bantock has done an intensive study of the factors involved in CBTF from the extraordinary power developed by the canting keel to the overall wetted surface of the hull/ foil combo etc.The info is there as well as a discussion of the tradeoffs involved in producing this design and the final conclusions reached by the designer.WHETHER IT IS microSAIL! OR JOE BLOWS BOTATYARD CBTF DONE TO THE LEVEL OF GRAHAMS DESIGN WILL REPRESENT A QUANTAM LEAP AHEAD IN RC MONOHULL PERFORMANCE!
microSAIL! has just concluded a deal with David Hollom a world renown aero-hydrodynamacist who has designed foils for Graham Bantock among others as well as
doing foil optimization on many full size projects including America’s Cup campaigns.
The addition of Dave’s expertise to the F100CBTF brain trust is a major development since the foil design on a CBTF boat is critical.
I’m proud to have Dave helping us on the F100CBTF as well as other special projects…
Doug Lord
microsail.com
monofoiler.com
High Technology Sailing/Racing
OK, I?ll try and get my point across once more here and then I?ll do my best to just steer clear of this.
Once again, yes, maybe reading these computer (I?ll leave the word friggin out as it seems to be more offensive to some then I intend it to be grin) results is interesting, but my point is that I just don?t predict success on the water. If you all are trying to make the fastest monohull on the water then you might be heading in the right direction, but on the racecourse, during a regatta, I think this concept will surely be doomed.
An example, again, ?.
The Wheelers were coming to the east coast for the 2003 Nationals, so a couple of skippers in region 1 decided to get a couple of boats. Two, pretty beat up Wheelers were purchased, one by Jim Linville and the other by Herb Dreyer. Jim had to do quite a bit of work on his boat to get it to sail well and mentioned to me how excited he was that the class rules had no restrictions on the amount of servos and there functions. He was all prepared to try and use up his seven channels with separate jib and main winches, backstay, traveler, boom vang, etc. etc. I told him to just stay with a rudder servo and a single winch for both sails, ?don?t even use a jib trim? I told him. Well basically this is what he did, not for my suggestion but because he had time constraints to do deal with.
So there?s Jim out on the racecourse with this beat up, rough hulled poorly rigged Wheeler sailing against the likes of George Ribeiro and the others from the West Coast, all of whom have been sailing these boats for years. Most of these skippers were running duel winches, backstays and other stuff. Jim basically blew them all out of the water that first day. Last over the start line and first one around the first mark usually. I watch as jibs were being trimmed in and out, as mains were not hauled in very well for the first few boat lengths and more.
OK, it was a long winded example, but what I?m getting at is that I sincerely doubt that the CBTF will be successful simply due to the fact that there is just TOO MUCH to think about when in fact you need to be focusing just about 100% on sailing rather then trimming this and adjusting that, let alone doing it efficiently. I?ve been there myself and have seen it time and again.
So, predict what you will about how awesome this technology looks on the computer. Just let me know when these boats hit the water and are ready to sail against fixed keelboats of the same general size. I?m more then ready to be proven wrong, but not by some computer program please.
I can only speak about my boat, the F100CBTF, in detail though I have been in frequent contact with John Beavis and I believe he is doing a first rate job.
In my philosophy of actually introducing CBTF to the rc sailing world first comes the science ,then comes the practice. It’s got to be abundantly clear to anyone who bothered to read the frequent reports and summaries I have done about Bantocks design that many areas of the design were studied ,tradeoffs compared etc. This ,in my opinion, is critical to the potential success of the boat. I have brought in possibly the worlds foremost rc yacht designer(Graham Bantock) and now one of the worlds foremost experts on foils(Dave Hollom) to help get the science part right.
In discussing this boat from its inception there were down times when it didn’t look good for CBTF and where certain “experts” said that Graham would “never recomend CBTF for production”. Then the elation of the final results that encompassed not only Grahams expertise but that of one of the great technical design institutions the Wolfson Unit.
You bet I’m enthusiastic and I’m confident of Grahams design but that is the first step. Now comes the optimazation of the foils ,the construction of tooling and finally the testing of the finished design.
Unfortunately, most people that contribute to this forum have NO experience sailing a canting keel/movable ballast boat: I have tons of experience doing it and so does Grant McKinnon designer and builder of the fabulous Ultimate Warrior(see his contribution under “Sailing a Canting Keel Boat” under “New Classes”) and I know that racing a boat with a canting keel is extraordinary fun and can be mastered by almost any sailor with some practice. I’ve also had lots of experience racing spinnaker equipped rc boats where handling the spinnaker also takes practice -and if you’re not reasonably good at it you lose.
I’m afraid that the reluctance of some to think that a canting keel boat can be raced effectively is based on a simple lack of experience–lack of foresight is not part of it but it is hard for some to envision sailing any differently than the way they are used to–that is human nature but conclusions can be drawn from those that have had the experience of racing both “normal” boats and modern multi fucntion boats. There is a huge difference between having a multichannel boat where you have ,backstay,outhaul,jib trim, etc-thats a lot to remember. But you can’t forget a canting keel: it is intuitive to sail with after practice…and loads of fun! As to what is possible under radio control look no further than the rc helicopter pilots using 9 channel radios flying $5000 machines. Surely if those guys can master the technical intricacy’s of helicopters we sailors can handle 4 or 5 channels!!! People can learn more than they now know; they can do more than they now do–you can’t possibly be saying that the rc sailor has reached his limit of evolution and anything further is impossible,can you?
Much of the controversy about this technology stems from a limited veiw of what is possible-thats why I have brought in experts such as Graham Bantock and Dave Hollom to help with the technology(science) part of the project and that is why I have posted so frequently and in such detail about CBTF-to try to help those seriously interested to understand the science so they’ll be ready to sail the boat. There is more information-detailed information-on this website than on any other forum regarding the science of CBTF both in full size and in rc applications than can be found anywhere else on the internet as far as I know. Further, I’ve made the effort here to describe under “Technology Discussion” the newest and most novel forms of movable ballast systems so that those interested in technology can find the information that might help them.
As I said: science first,then pratice–the F100CBTF project is well under way and is making great progress evey day–the sailing part is getting closer all the time and a rock solid technilogical program has been laid down to insure the best performance possible when sailing a CBTF boat.Stay tuned–
Doug Lord
microsail.com
monofoiler.com
High Technology Sailing/Racing
Greg,
You are absolutely right that whatever you do needs to be simple and intuitive. The more your head is in the boat, the slower you will be around the racecourse.
I have a sail trimming system on my Fairwind that allows me to dump the main without easing the jib. Basically, in the last few degrees of travel on the arm winch the jib sheet will over-center whereas the mainsheet will not. So moving the servo that last few degrees does not produce any change in the jib trim but I can trim the main in and out by about 10 degrees.
When I am sailing to windward, my sail servo stick is at the full in poosition and i adjust the sail trim with my fine tune slider. I keep one thumb on the fine tune and play it, much the way thatt you would play the traveler on a full sized boat. It works so well, that I can usually steer the boat by trimming and eeeasing the sail. This is a very fast way to steer the boat as the rudder causes a lot of drag whenever you use it. My college sailing coach used to make us practice without tillers on the boat so that we would have to steer the boat with sail trim and crew weight.
I can regularly sail entire windward beats using only my sail control fine tune. In my college dinghy days we could even roll tack without the tiller, but I have not figured out how to do that with my RC boat yet, so I still use the rudder to tack.
I credit this system (in part) for my win at the National Championships this year. Most of my competitors were also convinced…
As doug indicated, the canting keel control needs to be intuitive. I think it can be. I think that by putting the ballast (or canting mast control in my case) on the side-to-side channel of the sail trim stick, it will be very intuitive to increase the cant. Remember that increasing cant is very similar to shifting your crew weight to weather as the boat heels. So I think that you will respond by pushing the stick in the same direction that you would push your weight in response to heel. Once you have maxed out your hiking, then you need to start playing the traveler down as you get more and more pressed. since you are on that stick already, you will feel it hit the stop and then you will start to pull the stick down (or push it up depending on how you like to setup your Tx) to ease the sails.
Bottom line, I think it will be very intuitive to sail the boat. Especially if you are used to dinghy sailing where you respond to a puff first with body weight and then with easing the sheets.
Like doug says, shifting you ballast in response to heel is much more intuitive than adjusting backstay or cunningham tension to get better sail shape (something that is hard to see from shore) or adjusting jib trim to get better pointing or whatever.
- Will
Will Gorgen
We have been down this road a whole bunch of times already. For r/c racing there is a balance between speed gain vs. the distraction of additional functions. It is not a question of what functions can be controlled, its whether you get a significant advantage from the added complexity. I think if you ask most active racers they will come down on the side of Greg V.–the fewer adjustments the better.
On a seperate point about the “science” of yacht design --I don’t understand how you could obtain an accurate picture of a boat’s performance if you haven’t designed that boat’s foils.
And finally, I very much agree with Greg that the proof of all of this will be on the race course.
Bantock designed the boat and foils and at his suggestion David Hollom will be optimizing the foil section-and planform to the extent he finds it productive to do so;Graham is the doctor; Dave is the specialist…
Some individuals criticize new technology thru the back door listing all the problems in designing, building and sailing and emphasizing that due to the myriad requirements that need to be addressed the technology will never work-at least not in this century.
The fact is that such criticism made that way talks more to the personal limits of the individual making the criticism than it does to any limits of the technology–facts and the experiences and reports first hand from excellent sailors with experience in canting keel sailing both here and in New Zealand are discounted by individuals with ABSOLUTELY NO EXPERIENCE SAILING modern canting keel boats. Judging from the way some treat the already known facts it is unlikely that any “new” facts no matter how compelling will be treated any differently… I have a feeling that if a CBTF raceboat proves to be as fast as predicted in the science phase of the project the negative elite will simply say:“what do you expect–it has so much more sail area”!!!
Doug Lord
microsail.com
monofoiler.com
High Technology Sailing/Racing
Just thinking about this whole thing about computer modelling, and a thought came to me.
In the last America’s Cup, there were a total of 10 teams. Each one spent significant amounts of money on designing an ACC yacht - design efforts that, AIUI, without exception, all used input from computer modelling and tank testing.
Each design team drew the boat that they, and their VPP told them was the fastest.
One boat won. And won not only because she was sailed by very skilled sailors, but won because she had a speed advantage over the other boats.
Ed,
I think that if someone had seen all of the VPP and computer model predictions of the speed potential of the boats in the last AC, it would have been pretty obvious which boats were going to be fast and which ones had no chance. But of course none of the teams shared their performance predictions with any of the other teams so no one knew for sure that their boat was fastest. They knew that their boats were faster than the boats from the previous cup, but all of them expected the other boats to be faster too.
I think the VPP would have shown that New Zealand had the fastest boat in most wind conditions. If they had been able to tune it properly and build it so that it did not fall apart, most people feel that they would have won the match. Alinghi would have been shown to have a very fast boat as well, although I bet that Oracle’s boat would have been predicted to be a bit faster in certain conditions. The remainder of the boats would have probably been ordered in about the same positions that they finished…
In the case of Doug’s F100 program he has the VPP of his competition - Graham’s current IOM designs which are among the fastest on the circuit. So I am confident that the VPP predictions are right about the speed potential of Doug’s boat.
Of course getting a boat to perform up to its potential involves proper tuning, and a skilled skipper as the America’s Cup demonstrated quite clearly. This is why Joe Schmo cannot just buy the fastest boat on the market and expect to win races. But if you take two very talented skippers and give one a fast boat and the other a dog and give them both a chance to tune their boats, the faster boat will win the day. And the VPP would have predicted that.
Will Gorgen
<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by wgorgen
Ed,
I think that if someone had seen all of the VPP and computer model predictions of the speed potential of the boats in the last AC, it would have been pretty obvious which boats were going to be fast and which ones had no chance. But of course none of the teams shared their performance predictions with any of the other teams so no one knew for sure that their boat was fastest. They knew that their boats were faster than the boats from the previous cup, but all of them expected the other boats to be faster too.
I think the VPP would have shown that New Zealand had the fastest boat in most wind conditions. If they had been able to tune it properly and build it so that it did not fall apart, most people feel that they would have won the match.
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
Will, do you really think so? I think that NZ is the perfect example of computer misguidence. No way do I believe that they had the fastest boat at all! I will never forget those images of water squirting out of that Hula nor the fact that the boat almost sank! I just don?s see how that can be called a success at all.
<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>
In the case of Doug’s F100 program he has the VPP of his competition - Graham’s current IOM designs which are among the fastest on the circuit. So I am confident that the VPP predictions are right about the speed potential of Doug’s boat.
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
I have all the respect in the world for Graham, but the facts are that he has not designed a winning boat for the last four or five years now. Maybe this is not where his head is at at this time, but the facts are that his boats are not making the podium in major events these days. Correct me if I?m wrong, please, for I don?t claim to no all of the latest results.
<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>
Of course getting a boat to perform up to its potential involves proper tuning, and a skilled skipper as the America’s Cup demonstrated quite clearly. This is why Joe Schmo cannot just buy the fastest boat on the market and expect to win races. But if you take two very talented skippers and give one a fast boat and the other a dog and give them both a chance to tune their boats, the faster boat will win the day. And the VPP would have predicted that.
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
Again, I restate paragraph above. If this computer program is so correct in it?s predictions, then why are the Bantock designs not on the podium? Again, please, no disrespect to Graham
Graham Bantock missed the Worlds in Canada due to a personal issue(he would have loved to have been there) but he did win the English IOM Nationals in convincing fashion just a few weeks ago.
The attitudes expressed about VPP’s and computer aided design are unfortunate but when minds are made up despite the facts it is useless to discuss it…
But it is enlightening to realize that in an attempt to discredit the F100CBTF project someone would have the incredible lack of wisdom to try to imply that another reason it won’t work is that Graham Bantock has lost his touch!!! Of all the ridiculous and absurd charaterizations I’ve yet heard that takes the cake!!!
Not only is modern computer analysis discredited by some in a continuous attempt to show the futility of CBTF for rc sailing now the negative elite has turned on Graham Bantock -one of the best sailors and designers ever to be involved in rc yachting.
There seems to be no level too low for some to sink…
Doug Lord
microsail.com
monofoiler.com
High Technology Sailing/Racing
Doug, you are correct and I believe I misspoke on my last post. The Italico is a fast boat, but the fact is that Graham is probably about the best skipper out there. I will be patient and wait and see how your boat goes this next season.
I?m sorry that you feel that there is only one side to this computer discussion being that you seem to put all doubters in a class of misguided individuals and feel that there is no use of discussing it. I think that you have put yourself in this position by making claims that ?..The F100 final design is shown to be faster in every condition and by large and consistent margins -some approaching 500 seconds per mile!!! In light and heavy air! …? without so much as laying a hull. Strong statements such as these are like placing a target on your back. Don?t take it so personally when some of us have doubts, or just want you to ?show us the money?.
I am a woodworker by trade so I have an artistic mentality that keeps me from depending on the computer, or believing that it can do something better then my own hands. I have made several appendages for my boats that have proven faster then ones that have been computer driven. These appendages are all hand shaped from wood with no drawings to say the least. So, I still have doubts that computers can predict what will happen in our real world environment.
Doug, your edited post came up as I was writing mine.
Now I think you are being a bit of an ass. I never claimed that Graham has lost his touch, ever! You seem to continually interpret things in your own way.
Graham is very talented sailor who can beat the pants off of just about anyone. My claim was that his boats are not as dominant as I think you have lead to. Yes, when Graham is sailing his boat, you can bet it will win, but other?s seem not to be as lucky with the Italico, as I have heard that it is a difficult boat to sail.
It amazes me just how quickly you can turn on someone because they choose to discuses this issue and express their own opinions. This is one reason I have tried to stay quiet on this topic, and any other one that you are involved in. You are proving to be a dangerous guy Doug when you take my post and twist it like you have.Greg, you’re not even reading what you write ,it appears. You quoted me speaking about the F1OOCBTF DESIGN–those are the facts–but in no way was I trying to say we had a finished boat that had done that. Geez-that was a report of the actual results Graham found in his exhaustive modelling of the final F100 DESIGN-not the finished boat!!! I also had reported the earlier findings when it appeared that the CBTF system wouldn’t work on a model-almost at once a couple of the most negative of the “elite” pounced on that report saying basiclly “see ,I told you it wouldn’t work” and one went so far to say:“I predict that Graham will not recommend the CBTF boat for production”. Then later when the final results came in saying the DESIGN will work there is basically silence untill you use the quote from my report of Grahams findings to show that I go too far!!!
As to your remarks about Graham losing his touch I was not the only one that read it that way–it sure appeared that you were implying that the work Graham has done on the F100 is suspect because he is not winning anymore-your words more or less.
I guess I am a little touchy about comments that seem personally directed or directed at someone of Grahams caliber; there is a lot of hostility on several forums toward CBTF with one guy the other day linking a tragic death on SF Bay to CBTF and even when confronted with the facts still refused to retract the statement.
It’s flat out amazing to me…
Doug Lord
microsail.com
monofoiler.com
High Technology Sailing/Racing
Doug,
Greg questioned whether or not Grahams head was into designing fast boats lately, not that he had lost his touch as either a designer or a skipper.
Greg,
Without having sailed any of Grahams boats, I cannot comment on his boats. My comment was based on his reputation. It is interesting that Graham’s latest boat seems to be quite fast when sailed a certain way and not so fast when others attempt to sail it. This is something that VPP cannot calculate. This is where tuning and refining the boats comes into play.
So VPP tells you a designs potential. but it may not reveal how sensitive the boat is to off design conditions. This is a shortcoming of VPP (what little I know about it). The same is true of CFD. It will tell you boatloads about a particular condition but unless you run an analysis of every concievable set of boatspeeds, windspeeds, wave conditions, etc. you may not see a huge hole in the boat’s performance.
As far as the America’s cup goes, yes, I think that New Zealand had a very fast boat - especially in hull speed limited wind conditions (12 knots +). The extra waterline length of the Hula gave them the ability to design the boat outside the rule and put them at a distinct advantage. Their sail inventory left a lot to be desired and their structural design execution was shoddy at best. The biggest problem they had was poor tactical decisions. In more than one race they made the wrong call on the first shift and never recovered.
Not having an elimination series to tune their boat hurt them and I don’t think they ever got their boat up to its full potential. They showed huge speed in the race where they broke their boom (before they took on all that water). They showed amazing speed in some other races, but breakdowns and tactical mistakes will always cancel out speed…
Having said that, I feel that the Kiwi Strap-on was a huge cheat and was a big step backward in America’s Cup technology. This same cheat will become the norm the next time around (much like the double knuckle bow did) unless someone outlaws it. I think this will be distracting and will hurt rather than help the development of faster boats for the next cup.
Will Gorgen
Greg,
I want to respond to something else you said. VPP is a predictor of velocity, not an optimizer. You still have to come up with a fast design to feed into the VPP. So having a VPP at your disposal will not garantee that someone else will not come up with a faster design.
But what it does do is tell you if one design is faster than another. So if you feed it enough good designs it will pick out the best of the bunch. so, if you had a lot of time on your hand you could parametrically change a given design and feed these small changes into the VPP until you found the optimium. but again that would be the optimum within the design space that you varied your design within.
The bottom line is that the VPP will tell you the potential of a given boat design. And it will tell you with some degree of accuracy whether one design is faster than another and by how much. THere are a lot of assumptions in there, but it basically does a good job. If it didn’t, no-one would use it.
- Will
Will Gorgen
Will: There is no such thing as a single “VPP”. There are in fact many velocity prediction programs at many levels of sophistication. The more sophisticated, the more computing power required. Moreover, all are based on different assumptions and different base data. Some test hulls with standard appendages and rigs, others allow custom rudders rigs and keels. Some are based on steady wind speeds, others take into account acceleration and deceleration and tacking speed. Some are based on “flat” water assumptions others take into account various levels of waves. At the most sophisticated levels the base assumptions for setting up a VPP are exteremely proprietary. Further, in the case of model boats there is a much higher degree of uncertainty because there is less base data for boats around various courses then there is for say IACC boats around the course in Auckland. One thing I know is true, if you put a series of designs into a VPP you can not guarantee that it will tell you if one design is faster than another in the real world. It is a predictive tool, but not a substitute for the racecourse. I know for a fact that when many IACC syndicates put the “Hula” into their design software they did not obtain significant positive results and I think that was proved out on the racecourse. Moreover, in talking to many designers, I think there is a sense that the Farr Oracle boats were “faster” than Alligni but where not able to be actually sailed faster out on the race course.
As to Graham Bantock. He is one of the best r/c designers out there. On the one hand his boats did not do well at this year’s IOM Worlds, on the other in the past many of his designs have done very well in a wide variety of classes. Like everyone else, he (and his work) is not perfect. It was wise of Doug Lord to seek out someone experienced to design his boat; it will take a real boat in the real world to prove the concept.
I’ve never actually used any VPP software, but I do know a little bit about them. Roy is 100% correct that there are many flavors of VPP programs out there - most of them proprietary. They are all semi-empirical and as such they tend to fall down when you get too far outside their empirical basis.
In general most polars are generated by VPP programs. My experience with polars in full sized boats is that they tend to be pretty accurate. So I tend to feel that VPPs do a pretty good job of predicting the fundamental target boatspeeds for most boats. Then again all the boats I have sailed tend to fall well inside the established design box.
This is probably the biggest weakness in using VPP for RC boats. The database needed to establish an empirical performance prediction is probably fairly weak, as Roy said.
I followed with some interest the news that several teams had looked at the Hula. What I was able to glean out of their comments was that they found that as a pure add-on it was pretty marginal in terms on increasing performance. New Zealand on the other hand designed their boat with the Hula from very early on and therefore moved their boat design to a slightly different place in the design space. As such, they found an advantage that the others did not explore because their designs were complete already.
Of course the entire America’s cup fleet was within a very small boatspeed difference of each other. So you would probably need a pretty sophisticated VPP to really sort it all out. And all that would tell you is the “potential” of the boats. It is still up to the teams to be able to extract that potential from their boats. But then I guess that is why they get paid the big bucks.
- Will
Will Gorgen