Hi Breakwater,
double jib is nice to observe, but single jib is more efficient.
The multiple jib was slowly abandoned with the arrival of mechanical winches capable to handle large surfaces.
Today is more difficult to control multiple jib with modern radio-control servos and when it is done is just for the pleasure of the eyes for an historical era.
ClaudioD
Agreed re the problems of sucessfully radio controlling multiple jibs, but nonetheless the double / multiple jibs look great IMHO, particularly for older styles
No radio. The rudder control was a Boucher Corp (a leading supplier of model yachts, kits and fittings in the day) variation of a “pre-Braine” gear called a “Clyde Gear” in the UK and a “Marblehead Gear” in the U.S.
Cheers,
Earl
Are these displacement weights?
If so, you are in the range…
By Comparison, the Pocohontas VM By W.J. Daniels calls for a displacement of 6.18kg per-the-plans.
Actually, by the looks of it, the 12s and Js might have lower displacement values than some great VMs… With the exception of Enterprise, actually having a higher displacement value than the Pocohontas. Enterprise, The Tug-boat of the J-Class.
Actually there does exist some rather soft, light and flexible dacron that eliminates the water absorption and likelihood of distortion that makes the ripstop nylons such a temporary, short lived sail material. I use quite a bit of it for classes from the large 8’ J’s down to the Vintage Marbleheads.
Rod,
I have a suit of your Dacron sails. I don’t know if the ones I have are the exact material you are referring to, but… I can say without hesitation my sails from your loft are AWESOME.
They are maybe 3 years old, but definetley have at-least 2 years of competitive racing on them. I can also say without hesitation that these sails have zero signs of break-down.
However.
I am Personally going to a woven material called Dilon 100 for light air. It is Eqateable to maybe 3/4 or 1oz. Very light stuff.
I am using this material on my “A” Rig, and the Dacron on My “B”
No sailing with it yet, but it looks great… we shall see.
Vintage rules require a woven cloth, so you can’t use some of the exotic materials that you can in other areas of the M-Class (such as Test 505 or tri-spi stuff) The Dacron Material is surely way-more stable long term than the Dilon 100, but for a light-air rig it is way more sensitive.
I just don’t have any expectation for it to last 1/2 the lifetime of the Dacron.
I like to recall that at the end of two months pooling period, the 17 of April I will close the voting for the selection of model boat plans.
The models boats with the two highest number of votes per Group, will be used to draw the Plans, free of charge.
I do also recall that all models will be 127cm long over all to be compatible with the Vintage M Rules.
This is the actual Standing :
See Page 6
At the time of writing the following 5 models are retained :
J Class : Endeavour II and Ranger
12 Metre long keel : Columbia
12 Metre short keel : Australia II and Azzurra
ClaudioD
Hi Claudio,
I am thinking about Endeavour II
RGB
Thank you RGB
Table updated :
.See Page 6
ClaudioD
Two months!
To heck with that!
The sailing season is approaching. Let’s get to work!
Be patient please !
In any case any of that projects will take several months before getting to the water !
Personally I also need time to draw them.
Since the Australia II is the most voted one, I do have a concern about the short keel drawing to allow the construction with the use of wiglets and integration of ballast. Design details are taking me busy already.
ClaudioD
Haha.
I know… I wasn’t pushing. I was being more comedic but didn’t say it the right way.
Do it any way you wish… your work is awesome.
Claudio,
In case you have not seen the nice sideview picture of what is called a large Australia II model. You can hit - view all images in thread - to easily see it. You will probably want to read some of the thread. There is a small amount of info (and pics) about EC-12 size (I believe) Australia II and Nautic class wing keel RC boats in the thread.
http://www.rcgroups.com/forums/showthread.php?t=1800577
Yes Scott,
I saw it, thank you.
The Australia II, as described there is 1520mm long while here we consider 1270mm of length (50inches), 25cm shorter
ClaudioD
-Dear “ClaudioD”
-In days past, I voted in the category “short keel” by Azzurra, if you let me, I would also vote in the categories:
-“Long keel” by American Eagle
-“J Class” by Enterprise
-Regards.
Hi Alberto,
very good and tank you.
I will update the table meanwhile I like to introduce two examples, a JClass and 12Metres scaled to 1270mm or 50 inches.
Alan in pm is suggesting the use of gun shots balls to facilitate the construction of the Keel and in particular the Australia Keel.
This option requires of course an increase of volume since the specific weight of the lead shots is generally very low and some times less than 50% compared with lead .
The actual drawing below are not modified, but very probably will be necessary to introduce a deeper draft in order to keep a reasonable righting moment. The actual ratio considered is 50% in the ballast.
The lead shot I have requires some 35% volume increase.
I checked on the Web and surprisingly I found that it is possible to have shots with almost pure Lead and further I discovered also that it is possible to have lead powder.
For the sketch below I just calculated the specific weight to 7kg/dm3. The shots I have are 2mm in diameters and weighting 6.7g/cm3.
I’m almost sure that the ballast volume need to be further increased.
I would appreciate other opinions on the subject “ballast” with real lead or with lead shots !.
…
…
ClaudioD
Here the Table Updating
See Page 6
ClaudioD
If you ask me, the cast lead ballast method is far and above the lead shot method.
To the point of not comparable in a quality standpoint.
Often times when one builds one of these style Traditional boats from plans, they build the boat entirely per the plans on the keel shape. Then cut-off a section of the keel using a saw.
This section that is removed is then taken to a foundry to be cast in that shape from poured lead.
It’s not an accurate science… As for example a few pounds should be shaved off of the ballast outline for the Madcap to get it to float correctly.
There are very few, but there are still a few foundries in the USA that will do this service for you.
I guess what really matters is if you have access to a place that can cast the lead for you. If not you might be forced into the bird-shot and epoxy type method.
I know you’ve made a few boats, but I hadn’t paid attention to where you lead is coming from.
Beautiful!
One suggestion though.
The lead doesn’t have to be a vertical rectangular block (this is in specific regards to the 12 Meter Ballast) . As suggested above you could cut off the keel and cast a piece to the hull shape, and shave it to match the contours.
Not sure if you did that for drawing convenience.
But, You’re the builder.
Really, however you are most comfortable building the boat is what is going to work.
My suggestion was only in reference to a modern 12 metre (Aussie II) with winged keel feature.
Have been thinking about how to make keel ballast and had two options 1) cast solid keel in lead or 2) moulded keel and fill void using pallet lead (the small lead balls used in shot guns)
The winged keel is a complicated shape that most people do-not want to attempt with lead casting, therefore I’m thinking the second option is better of moulding the keel with a ballast void, which means keel split (2 piece) female mould if one wants to makes reproductions or using foam mould for single, one-off hull, where you can dissolve the foam using acetone.
The fine tuning for the hull weight distribution would much easier with pallets or using higher density lead shaving for previous bulb shaping in the void as you can then add or subtract weight to get it spot on and then just bond in place by flooding the ballast void with epoxy.
If a wing keel trim tab was introduced (which I would like to do) it would also be much easier to install the linkages within the bulb void (before adding ballast weight) than in the casting a solid lead keel.
Cheers Alan