This comment will cause some heated discussion. But in all the years that I have sailed r/c boats,monohulls and multihulls, there is one thing that has never changed, r/c sailing is 75% luck, that is to say that if you are in the right place at the right time you will benefit.
I have lost count at how many times I have lost races through racing,trying to tacticly beat everyone else. The best races that I have had is when I have spent the whole day sailing not racing.
What is meant by this is, go out to the pond,lake or where ever it is you sail and just go sailing, follow the rules, sail the course but don’t “race” against the other boats, you will have a much better day and stay more relaxed.
I don’t think r/c racing is “75% luck”. If that was the case the same guys wouldn’t end up winning all the time in a whole bunch of different venues.
I am also not aware of any r/c racing classes that have either an upper or lower wind limit on competition. ( I have seen races cancelled when no boat can complete the course within a time limit).
Finnally, gotta admire how Doug Lord sticks to his positions. Even though he hasn’t built or tested or sailed a retractable foiler, he has an explanation how it is not only clearly superior technology but faster than real boats sailing real races.
Oh, and hey, moderators, maybe you should split some of these multihull topics up, They are on a bunch of different subjects.
There was an article in a recent fullsize mag about “bang the corners” being history when sailing a new breed of multi’s like the F18-with square top mains and high aspect boards. I’ve personally sailed a 50" rc cat with soft wing rig and optimized foils against a fleet of EC-12’s in light and moderate air around a triangular course tacking on shifts as needed.
I think that the degree that this is possible depends on the lift/drag characterisics of the rig and foils more than anything else…
It depends on the number and length of hulls and their profile shape - not with board design or sail design!
Cats tack slower than Trimarans.
Trimarans tack slower than monohulls,
Short monohulls tack faster than long monohulls.
Short planing monohulls tack faster than short displacement monohulls.
It’s strictly the amount of hull being pushed sideways through the water and the amount of resistance in place. Sail design, and apendage design have little to do with tacking a multihull. (with exception of rudder - obviously)
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; 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 - let’s try this as a High Technology Sailing/Racing test -
forget all about speed, power, sail shape and appendage design ( or lack thereof)… let’s get rid of all the possible variables and look strictly and one issue - hull profile design.
A boat with little or no hull/keel rocker can tack as fast as similar length hull that has a lot of rocker? <font color=“green”>YES</font id=“green”> OR <font color=“red”>NO</font id=“red”> ?
Once this question has been answered we move to question #2
Just a couple of points. We now have the multi’s we sail tacking nearly as fast as monohulls in winds above 8 knots.
The improved tacking ability came about from trial and error. Hull shape and configuration was experimented with as well as rudder throw and sail design.
Square top mains are fine in the right winds, but they cause nothing but grief when the winds pick up. The amount of sail area high up causes the centre of effort to move to leeward and forward, which then results in pitchpole/capsize.
We have found (at least in our conditions) that high aspect pin head mains work best.
The other point is that if boats are made to light this will also cause problems. One of our members built a new boat and raced it in the recent titles. This boat had a sailing weight of 1.8kg. With number two rig up and sailing in four knots, he was hit by a gust(which didn’t show up on the water) and capsized. Main reason for this capsize was boat weight.
I have read on some earlier posts that there is talk about reducing the maximum sail area for the mini40. I think that if this was done it would be stupid. There is nothing wrong with the rig size. The problem is that people are trying to build boats that are to light and they are just getting “blown around”.
We can build boats that are very light(1.2-1.5kg) but really for our “normal” conditions there isn’t any point.
<font color=“blue”> Answer to Dick’s question.
A multi must have some rocker. Flat hulls will tack slowly, boats with lots of rocker tack slowly. Sorry Dick but I couldn’t answer that with yes or no </font id=“blue”>
That’s OK Peter - we can let that one slide by - my point was boats “with rocker” tack a bit faster than boats without! [:D]
Question Number 2:
On a consistant basis and in all wind strengths, boats with 1 Hull will generally tack better and faster than boats with 2 or more Hulls? <font color=“green”>TRUE</font id=“green”> or <font color=“red”>FALSE</font id=“red”> ?
It should be mentioned, that square top rigs being more efficient is only a half truth, its not that the sails are more efficient, because they have a square top. It?s that they more closely approximate an elliptical profile; elliptical is the most efficient sail profile. Czeslaw A. Marchaj explains this nicely in his book ?Aero-hydrodynamics of sailing?.
So just because a sail has a square top doesn?t mean it?s more efficient than a fully roached sail.
Depends on the rig and foils…
(Clarification: “foils” above refers to those foils used for lateral resistance: daggerboards, centerboards, keels and rudders to the extent that they are used for lateral resistance)
edt: clarification
Doug Lord
–High Technology Sailing/Racing
I’m sick and tired of reading about foils.
Question WHEN ARE WE GOING TO SEE A MINI40/F48 FOILER COME OUT OF THE MICROSAIL WORKSHOP?
You have been asked three questions now. One here and the other two by Dick, please answer them.
A rectangular planform is more likely to develop the “elliptical” loading often referred to but there are other factors that make a square top superior including better twist control–at least thats what I’ve read…
And the shape of the tip is better if it is not exactly square but with the “peak” higher than the “throat”…
It’s fine to say that square top rigs are better. This is very true in light winds. Once the breeze comes in though get the thing off the boat or go swimming.
At no time in the last posts was I referring to foilers; sorry for any confusion.
When I refered to foils I was refering to daggerboards or to a daggerboard.I’ll clarify the previous posts…
The type of rig and foils(daggerboard(s), centerboard etc.) have a large influence on the "tackability " of any boat including multihulls.
Big head sails(squaretops,elliptical or what ever else) all have the same problem, they all have the sail area to high which causes problems when the breeze comes in.
Doug Two and half hours ago you were asked the first of many questions. As per bloody usual you ignored them because you are unable to answer them.
Obviously your reference information didn’t have the answers to the direct questions.
Doug you make out with countless posts that you are highly experienced with sailing design and racing, yet you can’t answer simple direct questions.
I have thought for a long time now that you are nothing but hot air.
You refer constantly to “things you’ve read or heard”, nothing you come up with is based on personal facts and experience.
If you really new anything about sailing and design you could have easily answered the above questions, but as usual you don’t.
Wake up to yourself because nearly everybody on here has woken up to you.