SEQ titles

sorry Dan to over-rule you but this thread just got interesting.
Peter, square tops. the wind gets up, you let the top twist off, instant de-power. Your square top rigs were most likely too unresponsive at the tip, look at a modern winsurf rig and you will see exactly what I mean. The vesion that I built of dougs rig can be made to work so the top feathers in the gusts and comes back in the lulls-as a sqare top rig should. My Rs600 (full size boat) carries somthing damn near a square top, I have sailed in force 7 winds without reefing in relative control. If it had been the same size pointy top there is no way I would have been able to control it.

Luff 'em & leave 'em.

<font color=“red”>edited by Mod…Wis</font id=“red”>I will just point out that I’ve asked Will Gorgen to post here and enlighten us all. He is an aerohydrodynamicist and a rocket scientist; we all may benefit from his post. Of course, given the nature of things lately he may decide not to…

<font color=“red”>edited by Mod…Dan</font id=“red”>
<font color=“red”>promo</font id=“red”>

Doug Lord
–High Technology Sailing/Racing

Thanks for the unlock -

as to where I was heading - it is hull shape - not sail shape that aids (or detracts) from tacking. Just like a car engine has no bearing on steering ! (???)

A long straight hull is fine for straight-line performance and tracking, while a short, curved bottom is what makes changing course (turning) easier. Simply look at a variety of boat hulls - whether long rowing/pulling boats, kayaks, or racing canoes. For straight line speed - a flat long hull - for turning ability a short curved bottom !

None of these are impacted by what they use for power… sail, motor, peddle power or oars/paddles !

The current accepted method for around the buoys racing - regardless of what you read - for a multihull, is still straight-line speed. I’ll skip the rest of the questions for sake of flaming! My point is that it is strictly hull length and rocker (amount and location) that controls the manner and ease in which a multihull tacks. The ONLY time I will concede a sail plays any importance is if a jib is backwinded during the tacking process. This backwind (holding the current leeward jib position until it is sheeted to weather after the hulls cross the eye of the wind) helps “push” the bows across the wind - which is why sailing a uni-rig cat (A Class, uni-rig NACRA 5.5 , Inter 17, 18 Square, or C Class) tacking is done carefully, controlled and as few times as possible.

I’m sorry Doug - regardless of how many hours you “say” you have sailed an r/c multihull - until you put in “numerous hours” of actually sailing a full size catamaran I have to say your concepts and beliefs in what you read and what is being done makes your statements (or suggestions) a bunch of “hoooie”.

Perhaps, you really need to get out into the real world - attend some races, with your boat or borrow someone’s and try to put your theories into real life situations. Once you have done that, and have proven your theories on a consistent winning basis, … then perhaps you can base theory on experience. What you read in a magazine whether it is Sailing World, Latitude 38, or heck - even Popular Mechanics is generally printed to sell copies - it is not necessarily gospel as you often suggest.

Will be most happy to put you into contact with a few more experienced small beach cat sailors and they too might be able to straighten out your misunderstandings about tacking many times or only the needed minimum. Or - you can post to “CATSAILOR.COM” forum and find out for yourself! Matt Struble, past Worrel 1000 multi-time winner and Formula 18 US Nationals winner would be an excellent resource. I know him as an acquaintence from when I sailed in Michigan, and his skill and experience is second to none here in the US.

While I have no reason to doubt Will’s ability to discuss formulas, science of aerodynamics, or wing concepts dealing with sails and low speed foils (as in sails - not hydrofoils) - I doubt that the design of sail profiles has much if anything to do with the ability of a multihull to tack quickly. Matt Lingly recently found out that ideas, thoughts and conceptions about tacking a Tornado greatly changed (as did his opinion) after having actually sailed on one.

As most other offers made, I am sure through my network of cat sailing friends and acquaintences I could find you someone local to your area to let you demo a real catamaran so you can see for yourself - what you think is the new wave may not be so. Just let me know, and I’ll have someone ready near Orlando in a short period of time. Assuming like other offers, you are too busy, can’t make it, have other plans, then I would suggest you visit your library or marine chandlery and check out several good books on the basics of catamaran sailing. You will, in fact, find location of moveable ballast to play a greater part in efficient and fast tacking than any sail profile design.

Now - if Will is willing to spend time educating us on sail design for efficient power, I would be most interested in hearing his thoughts, theories and reasons - and would definitely keep an open mind.

Get out on the water and sail a boat. R/c multihull sailing is a hell of a lot different to sailing a full size multihull and s*** loads different to sailing any monohull whether full size or r/c.
Being about the only r/c multihull sailor on here that actually races the things, I will not listen to so called experts that sprout about how good this and that is. Until you actually try out these systems on a r/c boat BUT OUT.
I have been designing my own sails for quite a while now and I can tell you they work very well, they sometimes need re-cutting. The square top one that I used was the only one that was not made by me. It was made by a professional sail maker that races r/c boats. He was present every time the boat was sailed, and came to the same conclusion as me.
Square top sails(or whatever else you choose to call them) have a wind limit on r/c multihulls. I have already stated that square top sails are very good but they do have wind limitations.

As per usual on this forum, Lord has had people with differing opinions to him and he doesn’t like it.
Matt us usual comes to his defence not knowing JACK about racing r/c boats. Your experience and comments always relate back to real boats. This is a topic relating to r/c multihull’s.

Wake up to yourselves you don’t need to be a rocket scientist to work out sails. Basic geometry teaches you that.

Peter

Will correct me if I?m wrong, but there is no such thing as a ?rocket scientist?. It?s a made up term used to describe scientists working in the aerospace industry.

And Doug, Peters comments though a little harsh are still valid. You got yourself into a situation, claming to know what you?re talking about, because you read it in a magazine, and now that people are questioning you on it, you need Will to bail you out. If you can?t back up you claims with some kind of realistic proof, don?t say anything. In the future post of this nature will be deleted. Because just as in this case, all they do is piss people off.

On a side note magazines aren?t a place to get reliable science information.

-Dan

<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by lorsail

<font color=“red”>Since the square top rig is so much more efficient than a conventional fully roached (H16,for instance) rig the boat enters a tack sailing higher and faster</font id=“red”>; that is helped by the optimized high aspect boards and the combination of the two result in a boat that tacks faster…
I’m still trying to find the article…

Doug Lord
–High Technology Sailing/Racing
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
Doug - you post these stupid remarks without thought - don’t you?

  1. A Hobie 16 you reference is a very strict one design class which began in the mid 1970’s. That sail design technology for multihulls has long since passed - might want to try to keep up with the new technology if you want to make intelligent comparisons.

  2. Comparing a modern (late 1990’s) fat-head to a 1970’s Hobie 16 LOW ASPECT RATIO sail/rig combination isn’t worthy of discussion or consideration. It’s like comparing a 1970’s car to a 2000 year model - NO COMPARISON!

  3. A Hobie 16 was not known for it’s tacking ability. It also was not known for hull volume, anti-pitchpolling, or great speed (although for it’s time it could … nawww - the Prindle 16 could whip it in moderate to heavy winds!)

  4. For a boat with so little stability, they stayed with a low aspect main to keep center of effort lower than the center of effort in your proclaimed Fat-head/Square-top. It is easy to understand for even us non-scientists that a center of effort higher on a fat-head makes for less stable sailing. Peter also pointed this out in his posts.

If you must use comparisons of class boats you know nothing about - try to at least keep the designs in the same decade?

By the way - Hobie 16 was/is the ONLY multihull beach cat, (to my knowledge) that used full battens in the slightly overlapping jib. This was a big mistake in light air ! Not only did the battens NOT pop over to the other side, the batten tips extending beyond the jib leech tended to catch on the front of the mast during a tack ! Thus a crew person was always responsible to manually pull the jib across and give it a hearty shake to pop battens to the leeward side of the sail.

Please - at least use a boat that was known for innovations as example - not one that was simply the “FIRST” !
<hr noshade size=“1”>Hell - after sailing a Hobie 16 for 2 summers for a dealer - <font color=“green”>I forget the most important point </font id=“green”>- since you WERE discussing tacking… <font size=“3”><u>The Hobie 16 DID NOT have daggerboards or centerboards ! </u></font id=“size3”>Any modern beach cat sailing today that is performance oriented (ie: Fathead main) uses a daggerboard!

Of course there is a difference in tacking ! DUH!

Gee, Dick, the whole idea was to compare old technology(the H16) with new technology (the F18).
To show the progress made in tacking and tactics and to ilustrate how important the squaretop rig and highly efficient daggerboards were to that improvement…

Doug Lord
–High Technology Sailing/Racing

DOUG - read my lips …<hr noshade size=“1”>
<center>the SQUARE TOP mainsail had NOTHING TO DO WITH IMPROVED TACKING

  • like I have been trying to tell you all along! [:-banghead] </center>
    <hr noshade size=“1”>
    <center>[:-dunce] It’s the boards Dummy, and the hull profile shapes … NOT the sail profile !</center>
    <hr noshade size=“1”>
    You are jerking my chain - right?
    [:-crazy]
    You can’t be serious about what you are posting - right?
    Meds haven’t kicked in yet - right?
    Peter put you up to this - right?
    You are just posting to see my reaction - right?
    You really don’t believe what you are posting - right?

hey guys I picked up on what Lordy, Lordy,Lordy has been trying to do with this for a while now. He needs some-one to mention about crew weight on the “real” boats so that he can p*** us all off with the movable ballast system and the foiler rubbish etc. Then when it does come into it and we complain he will then say that we bought up the crew weight arguement.

I see that the original straight forward questions still haven’t been answered.
Still can’t find the articles to back you up hey?

Peter

Good Morning Gentlemen (I use that last term loosely).

First, to answer Dan Sherman’s question: “Rocket Scientist” is a term that was coined when rocketry was still an experimental field (Von Braun, Goddard, etc) It has long since passed into the realm of engineering with much of the basic science now reduced to computational fluid dynamics, structural engineering and combustion modeling. So it is a term that perhaps no longer applies to those of us who make a living designing jet engines and rocket engines. But, since it has been adopted by the common culture as denoting someone with superior technical know-how, we wear it (jokingly) as a badge of honor. If you must know, by “job title” is Engineering Specialist… How dull is that?

OK, I just spent 15 minutes reading the last few days worth of posts and I am totally lost as to what you guys are arguing about! Near as I can figure there are three argument:

  1. What affect does hull shape and the number of hulls have on the ability of the boat to tack.

  2. What affect do the appendages (rudder(s) and daggerboard(s)) have on the ability of the boat to tack.

  3. What effect does the sail shape have on the ability of the boat to tack.

It seems obvious to me that all these peices must be working together in ways that you cannot really seperate in order for the boat to tack well.

Tacking a boat (any sort of boat) requires that you have enough momentum going into the tack to maintain speed (and therefore steerage) all the way through the tack even as the drag of the hulls, appendages and sails try to slow the boat down. I am going to ignore a common technique that we used to use in the Nacra 5.8 in extremely light wind which was backwinding the jib to “push” the boat through the final part of the tack as I think this is not a techique that is easily incorporated into RC boats…

The momentum of the boat depends on the mass and the velocity. The more speed you have before you enter a tack, the better chance you have carrying that speed through and maintaining steerage as you come out of the tack.

We all know that when you tack a boat it does not pivot about a single point, but instead follows a arcing course through the water. The degree to which the hulls must be pushed sideways through the water depends on the tightness of the turn and the beam of the boat. One of the biggest differences (in any type of boat) between the best sailors and the hacks is their ability to tack the boat well. If you “slam” the boat through the tack it is slow. If you turn too gently that is also slow. The best skippers know how to ease their boat into the tack and tighten the turn just enough to get the boat around without spending too much time but without bringing the boat to a stop. This applies to RC monohulls, multis, full sized dinghies, keelboats, multis, scows - every boat I have ever sailed. They all respond a bit differently and finding the best rate at which to tack each kind of boat takes practice.

But assuming that your tacking technique is pretty good, there are aspects of the hull design which can affect how much the boat slows down during the tack and thereby affects how much distance you loose by performing the tack. In a monohull, the amount of rocker can have a significant effect on the tacking ability. But rocker has effects on other aspects of the boat handling (pitch resistance and wavemaking) so you must comprimise all of these aspects to get the a boat that is fast when sailing a straightline course as well as when tacking. There is also a tradeoff between draft and surface area. A boat with low hull draft might skim over the surface of the water when you are tacking but the extra surface area will cause more viscous drag.

In a multihull, there are some other aspects that will effect the amount of resistance created by the hulls as you tack. The beam of the boat will have an effect since the wider the boat, the tighter the inside hull must turn and the more the inside hull will be pushed “sideways” through the water. With a trimaran, one of the amas is out of the water at all times, so the seperation between the two hulls in the water is less than a cat would have. This helps the tacking of the boat. I think this is what you were getting at Dick, right? Second is the hull shape. Since there has been some discussion on the Hobie 16, I think it is useful to take a look at those hulls as an example here. The Hobie 16 does not have daggerboards (as Dick stated). This means that the hulls mush generate the lateral resistance to keep the boat sailing in a relatively straight line. In order to help this, those hulls are designed with a lot of rocker and a sharp “V” shaped cross section such that they form a sort of long, shallow draft keel. If you try to turn this hull shraply through a tack, it creates a lot of drag because of this shape. The Nacra 5.8s that I used to race had a much shallower “U” shaped cross section with gentler rocker and less draft. Much of the lateral resistance on that boat was created by the daggerboards. This made the hulls much less resistant to turning sideways through the water and therefore had less resistance while tacking. I think this is what you were getting at earlier, right Dick? The position of the daggerboards dictated to a large degree where the hulls pivoted during the turn and therefore how much hull length forward of that point had to be pushed sideways. So the fact that you have daggerboards allows you to design a hull shape that will tack more quickly. The position of the daggerboards works together with the hull shape to dictate how much drag is created during the tack. So the hull shape needs to work together with the appendage design to effect how the boat tacks.

Rudder design can have a big effect. About 10 years ago, I was contracted by a family freind to design a new set of rudders for his A-scow. The oringinal rudders (designed in the 1920s) were about twice as long as they were deep and basically rectangular in planform. They were flat plates cut out of 3/8" sheetmetal. And they were way too small. We referred to them as the “postage stamp” rudders due to their shape and small size. They basically didn’t work. The skipper could push the tiller all the way over and the boat would barely turn. The only way to tack the boat was to have the jib man ease the jib while the skipper pushed the rudder. This created a lot of drag during the tack as this low aspect ratio “postage stamp” tried to push the boat around with massive amounds of ventalation and tip vorticity. I designed a high aspect ratio elliptical rudder with an airfoil shape cross section. The rudder had the same surface area as the postage stamp, but because of its shape was able to create much more lift when deflected while at the same time generating much less drag. Just after leaving the dock on the initial sea trials, the skipper decided to “wiggle” the rudder. The amount of control authority of the new rudders caught him off guard and his “wiggle” caused the boat to turn so violently that the crew all ended up getting thrown into the bottom of the cockpit. But the biggest change was in the tacking ability of the boat. The lower drag of the rudder allowed the boat to maintain much more speed during the tack which caused the boat to exit the tack much faster than with the old rudders. The jib did not need to be eased in order to tack which allowed the boat to carry more power into the tack. The tacking ability of the boat was greatly improved by incorporating a more efficient rudder design.

Now what about sail shape? Well the sails will have two effects. First, they will dictate how much speed you have going into the tack. Doug’s example of the H16 to F18 is perhaps not the best, but if you put a sail that was of similar shape to the F18 sail onto the H16 with the same sail area that the H16 has now, it would probably be faster which would allow it to tack easier. Secondly during the tack, the sail is luffing and creating only drag as the wind passes over it. To a very small degree, a more efficint sail planform will have lower drag and therefore help the boat maintain speed through the tack. But assuming the sail area is the same, this must be considered a very small effect compared to the drag on the hull… So unless the more efficient sailplan carries you into the tack with more speed, it will only have a small effect on tacking ability.

So, let me summarize what I believe are the most critical factors that will dictate how well a boat tacks. First, a trimaran due to the lower lateral seperation between the hulls that are in the water (center hull and ama) will have less resistance when tacking than a cat (and a monohull will have less resistance than either of these). Secondly, a boat with daggerboards will be able to hull shapes that are much easier to turn. Thirdly, the rudder shape is very important. Finally, the main influence of sail shape is to allow the boat to have more momentum when entering the tack which keeps the boat moving through the tack.

I’m not sure what I have added to this discussion. It seems like you were all saying pieces of what I just said. Perhaps by putting it all together I have helped? Maybe I have just created more controversy. I don’t know. I hope you don’t need to be a “rocket scientist” to understand these things…

  • Will

Will Gorgen

“I’m not sure what I have added to this discussion. It seems like you were all saying pieces of what I just said. Perhaps by putting it all together I have helped? Maybe I have just created more controversy. I don’t know. I hope you don’t need to be a “rocket scientist” to understand these things…”

Will…

thanks a lot for this reply…very clear,and very easy to understand(at least for me [;)])

Again thanks a lot…you are more than an engineer…you also know how to make things and explain things more easily!

Thanks

Wis

_/ if it isn’t broken, don’t fix it! _

http://wismerhell.esmartdesign.com/index.htm

Will - you pretty much summed up all of the various points I had made.

My only comment (as a personal observation) seems to be the issue of sail profile shape and speed. I would find it highly unlikely (could be wrong) that there is a significant difference in hull speed on the same size boat (class) whether the top of the sail is fat or pin head.

My experience - (Traverse City, MI - September 1983 - US Nationals 18 Square Meter Class) was the pin head sails provided by the Skip Elliott/Harry Pattison sail loft in California were easier to control and provided the same boat speed as the fuller top (not fat head) Sails on several boats that came from the Randy Smyth sail loft in Florida! Of course, there was a difference in skipper skills, but on a long leg to windward, there was little decernable difference between the two types of sails. On the one day when winds were up around the 17-18 mph range, it was easy to see the guys with the Smyth sails needing to twist the top off considerably to reduce heel - as the sail area was too high in the air for the wind conditions. The only cat that provided consistent speed, control, and sufficient power in any of the week’s wind conditions was the solid wing sail on WILD TURKEY - the cat from California. And to add a bit of additional conflicting information, to the above topic of sail shape … the wing was 28 feet high, while the other soft sails had luff lengths ranging from 30 feet to 33 feet in length.

It has always been my (personal) contention, that a lower aspect ratio sail that could produce the same power upwind as a taller, high aspect ratio sail would become better and better as the wind increased, as there was less tipping/heeling to be concerned about. No different than adding beam to a cat - a 12 foot wide platform will be more stable than the 7 1/2 - 8 foot wide platforms like your referenced NACRA 5.8 !

I think it has been mentioned by various people on this form (Matt Lingly and maybe John Storrow?) that two low aspect ratio sails would seem to have better performance than one tall rig with the same sail area in conditions as wind increased.

On the disussion of hull rocker, daggerboard design and placement, this photo taken during the Formula 18 Worlds clearly shows the most current design in lightweight, BUOY RACING multihulls.
Download Attachment: [ F18_DartHawk02.jpg](http://www.rcsailing.net/forum1/data/dick lemke/2004527102740_F18_DartHawk02.jpg)
57.67KB
These are not design opitmized for long-distance, off shore racing! Round the world boats (cat or tri) have a whole different set of parameters to which they must be designed. This F-18 hull is designed to be tacked as fast as possible (for a cat), to have stability and hull volume for waves, yet thin fine entry - also for waves.

To go to an offshore hull design as a basis for low speed, pond racing and to try to incorporate technology best used during extremely long distance racing on the same tack for hours just doesn’t seem logical for r/c sailing. It is my opinion that there is a vast difference in design theory between an Open 60 multihull, an 18-20 foot high performance beach cat, and a 4 foot long, multihull r/c pond racer! To try to lump all together and cover with a broad, one stroke of the brush is just plain rediculous. We have already agreed that sail area and keel depth do not scale accurately from a full size boat to an r/c model - why would we blindly make statements that what happens on a beach cat can/should be replicated in the performance of an r/c multihull?

I really think that before some magazine articles are taken as fact, one should give thought before posting - whether it is happening, or if it merely a concept. Since you have indicated a former period of sailing a NACRA 5.8, I guess my question to you since Doug asked you to comment on his post and theory is if you feel that tacking a 5.8 upwind in shifty conditions makes sense, or if like a majority of cat sailors - experience has told us to “bang corners” and go for boat speed?

Hey there Dick,

My Nacra racing days were many years ago and things are sort of fuzzy. I also raced Hobie 18s for a couple of years (1984 and 1985). I remeber the Hobie was a BITCH to tack especially in light wind (I was also racing X-boats at the time, so my basis for comparison was 16 foot hard chine dinghies). I remember the Nacra being a bit easier to tack, but in the lighter winds it was still hard and involved lots of body movement and backwinding of the jib.

Unfortunately at that time, the primary course sailed by the catamaran racing association in southern wisconsin consisted of a beam raching course (back and forth and back and forth in a big drag race… blah!), so there was not a lot of tacking except at the buoys.

I did race in a few regattas that used windward leeward courses and we generally banged the corners (especially in the H18). I do remeber one Nacra regatta where we played the shifts and it paid off pretty well, but it was a hell of a lot of work getting in off the trapeeze so many times… That race had 20 degree oscillations and most of the guys were playing them. The few that did not (that banged the corners) were not that far off the pace, but they were behind all of us who played the shifts…

More recently (1995), I was in Bermuda for Race Week and there was a fairly strong Tornado Fleet in the regatta. Several olympic guys were there including mort of the hot europeans at the time (Elstrom in particular). I was racing IODs so the Tornados were a lot faster than us and would tend to overtake us on the second beat. I remember they were doing a decent amount of tacking. Perhaps not as much as we were in the keelboats, but they were not spread out in the two corners. I particularly remember one of them who took a “short hitch” as he was coming up behind us so that he would not have to pass through our wind shaddow. He clearly considered it worth it for him to take two tacks rather than sail through the wind shaddow of a 33 foot keel boat…

Having said all that, i imagine there are some pretty big differences between RC multis and beachcats. First off, RC multis are much beamier so you would tend to pay a higher penalty in the tacks. Also, you do not have the ability to shift your weight around to get the bows up and skimming during the tack. You also do not have the ability to backwind the jib to help the boat around. so I would think that RC multis would probably be more prone to corner bangging that modern full sized beachcats. But having not sailed one, this is only speculation on my part…

  • Will

Will Gorgen

Check - and thanks for your opinion/thoughts

<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by Peter _Birch

Matt us usual comes to his defence not knowing JACK about racing r/c boats. Your experience and comments always relate back to real boats. This is a topic relating to r/c multihull’s.
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>

OK, I have two r/c multis, I have never raced them bar a few informal match races with a couple of local guys. You are lucky to have a local fleet, I would kill to have one here. My twin rigger you may have noticed has square top rigs, when the wind gets up, you ease the vang, it lets the top fall off, like a winsurf rig. I have sailed this boat a couple of times recently in winds of a well up to a force 5 carrying full sail. I am convinced it works, and I have found similar results from the version I have made of DL’s squaretop. Ok, perhaps there is a point where you would still be better off reefing when racing, to get the best out of the boat. I am not defending Doug while knowing jack, I have actually tried these things, and i have found them to work, if they didnt I would say they didn’t!

Luff 'em & leave 'em.

The “bent back tip” square tops I use have an upper outhaul that allows the camber at the top of the sail to be changed just like you do with the outhaul on the foot. John Beavis has incorporated a similar adjustment on his squaretop.
These type sails, if done right, are advantageous in every condition because their shape is so adjustable and because when set properly in heavy air they have a “springiness” to the head which allows automatic gust response.
The planform, tip shape, upper outhaul, adjustability,“springiness” in heavy air all combine to give these sails great power thruout the wind range.
Again, a square top with the same boom length and area as a pointy rig has a LOWER center of effort!
For those still thinking of Spitfire wings see: “The Design of the Airplane” by Darryl Stinton…

Doug Lord
–High Technology Sailing/Racing

<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by lorsail

For those still thinking of Spitfire wings see: “The Design of the Airplane” by Darryl Stinton…

Doug Lord
–High Technology Sailing/Racing
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>

p93, <u>Sail Performance</u>, CA Marchaj, revised edition

Wis

_/ if it isn’t broken, don’t fix it! _

http://wismerhell.esmartdesign.com/index.htm

<center>My first “real” view of the innovative, remarkable, adjustable, Wing Tip Rig <font size=“1”>™. </font id=“size1”></center>

<center></center>

<center>Will let Doug add his “spin” as to “why” it couldn’t be adjusted! Obviously operator error - even though there were 4 of us trying to figure it out. </center>

Amazing! Four guys ,huh? At the same time that boat was sent out her sistership was sent to an 83 year old man with a moderate amount of full size sailing experience and no model experience… He had no rig trouble and was on foils right off the bat.
Maybe the pictures on the website would have helped you figure it out!
But maybe you’re right: it is just too complicated for the average rc sailor; oh well, back to the drawing board.

Doug Lord
–High Technology Sailing/Racing

Doug - sorry - no internet access on the pontoon boat to verify your website photos.

I know “WHAT” it was supposed to look like, but none of the 4 of us could MAKE it look like it was supposed to. Let me guess here a little …

The gaff, crane, or whatever the hell you want to call it - simply is not long enough! If one were to pull out the trailing edge of the main sail “tip” to remove the wonderful wrinkles that are a speed additive - even that 83 year old man would see the length of the crane/gaff is simply not long enough to attach the sail to remove the wrinkles. Look at the trailing end of the gaff - TOO SHORT !

I really do suggest you go back to the drawing board and recalculate how long the tip crane/gaff must be in order to attach the tip of the sail. If the gaff only extends back 3 1/2 inches, and the sail material when attached to the mast extends back 4 inches, I would expect to see a 1/2 inch wrinkle in the sail.

Not operator error, not set up adjusment problem - strictly Shi**y Quality Control from Microsail!

But I do give you credit for arguing with the customer and telling him the mast was upside down… like that would make the crane longer in length !

Want to try a different excuse?