I am assuming that Lake Lefroy is similar to out dry lake beds here in the states. Meaning that there is little rolling resistance compared to typical beach sailing. I am assuming this allows a slightly smaller sail area may work fine unless the wind is light.
How does an altered windsurfer sail stack up against a made for landsailing sail?
If one alters a windsurfer sail or has a sail made how do you know how to tell the sail maker what the luff curve should be?
I read up on the Blokart website about masts. They indicate a stiffer mast is faster. Have any here came to that same conclusion?
What would one be looking at price wise for a sail like the airtrack sail on AUS 230 mini and the approx freight cost.
Thanks
John
Read this and it explains about the luff curve required, www.seabreeze.com.au/forums/Land-Yacht-Sailing/Sail-making/How-I-recut-sailboard-sails-to-suit-landyachts/
The template of the luff curve on step 3?
1) Do you copy the existing luff curve of the sail for the template when using a windsurfer sail?
2)If so if one went from a say a glass mast to a stiffer carbon mast would the luff curve based off the glass mast still be suitable for the carbon mast?
3) I would assume mast bend to be lower when used for a landsailer rather than a windsurfer rig with a typical windsurfer wishbone boom? This would be with the mast tube at 250mm.
US772,
I do not claim to know all that is to know about Sail Re-Construction but here is what I have learned.. For very hard surfaces ie Tarmac, Concrete etc. The flatter the Sail the better. The Sail Shape comes from Wind Pressure and Battens. (I use mine on Sand surfaces that are as hard as a Dogs Forehead).
Ron you need to do some more (a LOT more) study on sail design.
US772,
I do not claim to know all that is to know about Sail Re-Construction but here is what I have learned.. For very hard surfaces ie Tarmac, Concrete etc. The flatter the Sail the better. The Sail Shape comes from Wind Pressure and Battens. (I use mine on Sand surfaces that are as hard as a Dogs Forehead).
I have used 100% Carbon Fiber, Glass and am using 60% CF at present. What I have found is Glass is slower and feels generaly softer than CF, however that mast was very old.
Gaastra 100% is good and I suggest that if you can get them they are a good place to start, however I should look seriously at there construction.
At the moment I am using a Neil Pryde 60% CF Mast and have found it to be a great improvement on the Gaastra. Reason for this turns out (I think) that this particular mast is slightly heavier in construction in that it has a std base dia' but is a deal larger in the head dia which in all has produced a stiffer mast, which in turn produces a more swift reaction to wind gusts. The Gaastra's though softer in action (To use a fishing rod term "Slower") tend to absorb a wind gust and then release it as the gust passes. This then is released back into the Land Yacht making the hold an acceleration less but for a longer period, where as the Heavier head in the Neil Pryde will cause the Craft to tend to Accelerate Heavily, lifting the upwind wheel and possibly falling on its side.
"Horses for Courses"; Conclusion, Your choice of mast in my Humble Opinion should be in keeping with your ability at the time i.e a New-be should lean towards a softer mast .
Sail Cutting.. I haven't used a purpose made sail but it it my guess that there would be very little difference is the Job is Done Properly. Again I used Large Area Sails to start with, this gave more to play with. Going on what I had seen and discussed on the Forum I chose my design by eye and cut the Luff Edge of the sail ( I admit it took a couple of attempts to get it right). Following the Template on the pages below.
www.seabreeze.com.au/forums/Land-Yacht-Sailing/Sail-making/How-I-recut-sailboard-sails-to-suit-landyachts/
I re-cut my 11sq'm Speed Surfing sail to shape etc and then took it to my local Sail MAKER (The man knows his Onions) and had it sewn together.
In making the decision on Sail Cutting one should look carefully at the type of surface that is going to be sailed and Cut the sail accordingly i.e. Softer surface like Grass, Softer sand etc should be a fuller and larger sail area. Hard surface such as Hard Sand, Tarmac, Concrete etc should be a slender, Flat cut which will make your LY go faster.
Much of the above can seem daunting to the uninitiated BUT if your time is taken and the thought process allowed then common sense should give you your requirements. ABOVE ALL talk to us and hopefully we shall get you on the right track.. I did and I got the very best of advice. Keep in mind these members; Landyacht, TP1, aus230 there are others only too willing to help. There are no Silly Questions just unknown answers. ASK.
When setting up a Mast it is strongly suggested that you should Turn up a Long Plug 750mm to a Meter long from a strong flexible timber like Tassie Oak/Ash, Hickory etc with a good straight grain a wavy grain is also good so long as it is running the axis of the plug. This will support the base of the mast and prevent crushing and snapping ao the mast base. Wind Surfer Masts are not built to be Rigidly Suspended by their base.
Ron
PS; Under the Neil Pryde mast Occum's Razor is a bit faster and more twitchy but a "Hell of a lot of FUN"
PPS. www.c-f-c.com/specgas_products/so2.htm
AUS so2 is also an apt description of man and machine in strong windy conditions
Ron you need to do some more (a LOT more) study on sail design.
Thanks for all your input.
I wind surf as well. I have a 10sm sail that I may consider cutting up for a mini sail. I also have a 520cm - 17' 1'' mast @ 75% carbon. I have some friends compete in mini at the last Worlds in France. They liked it a lot. I really like the simple mini rules and the openness that it leaves to create your own boat. I'm leaning to a flat sail for my conditions. I'm thinking somewhere between 4 or 4.5 sm sail area. The mast and sail height I'm not sure what to do. I know with the solid wings I goof around with that the taller the less drag and more speed but also more apt to hike.
Should I use the 10 sm for a bigger 4.5sm sail and look for another to alter for a smaller higher wind sail? I weigh about 165lbs and if I build the boat will probably more on the heavy side than normal.
Thanks
I made a drawing of my 10sm windsurf sail. This is how I may alter it to suit a mini. 4.5sm sail. I'm not sure if I should make the the top larger and the foot smaller to keep the same area. My thinking is a larger top may fall off easier = depowering on top. Any advice or comments on the drawing?
Thanks
John
John , My feelings on that (For what they are worth) is that it looks good but were I you I would take the Luff down according to our Sail Making, Luff Template. I also think you should put a few dimensions in so that the Big Boys have a bit more to go on. Regardless of what others may say it would be expedient to stick to Sail Making and Construction Plans, dimensionally. Any changes you might make at this stage should be more or less superficial. Talk to Dessertyank and Sabydent as they have both built LLF Minis, made changes etc. There is nothing like experiance to sharpen ones perseption..
Gizmo,
I did qualify with "I do not claim to know all that is to know about Sail Re-Construction but here is what I have learned" You also have to remember that I was working Hand in Glove with Landyacht, TP1,aus230 etc as well as a Sail Maker how does Global Trade. Like Paul said, I put my money where my mouth is and what I have learned is what I was putting forward. Yes I do have a lot more to learn about Sail and LY Design but I'll not bother. I have had a busy 67yrs and can't fit a hell of a lot more in my Noodle so I will continue to use the expertise of those that know better as well.
I did find the Common Sense was a big help as well, much of what I was told was already down in drawings and thought.
Ron
I reread the sail making section and re figured the luff chart in inches instead so I could better understand it. I re drew the sail accordingly and found I needed a bigger square top to make up for the area lost on the luff. How far up should the plug go up the mast? Is a wood plug suitable?
us772,
Good man now the experts can disprove my thoughts..Ron
Did you alter the luff alignment. It looks to me like you improved it..
US772
Perhaps I should follow my own advice when reading articles.. Read the bloody things properly!! SOF (Silly Old Fart)
Yes you did alter the Line of the Luff Good..
Insert Base Plug.. I reckon it should be at least 750mm up to around 900mm (Limited by the Lathe Bed), the top 25mm/1" should have a rounded taper to it around 3/16" to 1/4" (Shees! Going back to old money is getting harder the farther we go) Deep. This is to help stop excessive pressure in one concentrated spot and mast breakage. The same as a "Bell Mouth" Should be created at the top of the Mast Step. Sudden Gusts can break your mast and bring a Sail down about your ears. This I know from experience, another tip is: If and when you get out of control cause you craft to loose traction into a slide and hold the Sheet Rope in tight. Yes! It is scary at first but becomes addictive[}:)][}:)]
and helps protect the Mast against Shock Loads.
OK Guys,
Here is a good time to bring in a problem I have with the "Big Wing Pocket" I have found the in winds around 25knots Occum's Razor tends to accelerate heavily and become hard to hold in a straight line, also the Steering becomes very twitchy.. It has scared "The Bejesus" out of me, especially when it did a complete 540degree spin and ran down the beach backwards about 25mtrs
.
Ron
...... what specs are you reading
I will probably get cried down on this But here goes.... When situating the Eyes for Sail tie down I would be inclined to Have a Webbing Loop sewn into the Leading Edge of the Pocket For firm Tie Down and a Reinforced Eye let sewn into the Luff edge of the Sail Proper for use with the Crockett system of Sail Tensioning coupled into the Main Sheet. The Rear Leach -Foot Eyelet Reinforced strongly in the Leech-Foot Corner (several Layers of Sail Material.) But Damn! That is a seriously nice piece of gear you are using. Get the most out of it..
Ron
bloody nora. thats a chook size sail. just leave it as is, mount it and blow.
you'll be in the same league as that austrian fella before you know it
...... what specs are you reading
...... what specs are you reading
GOTCHA!! Gizmo,
Being as I rarely use Schrodinger's Cat I would suggest that Paul was Referring to Occum's Razors Sail. O.R is a bit too big to be called a LLF Mini. It was built to Pac' Magics Spec's and wasn't built with Competition in mind.. Just as well as there is only me to compete against. Yeah! The Lord Admiral (Nelson) is still sailing at Pegs and I far and Away prefer Anthony Beach as it is straighter, wider and has less people on it to get in my way ( Less Dogs to hit as well)
None the Less I cut both sails and rebuilt them on minimal other materials and reused the pockets as is.
If what Gizmo says is correct (I do not know) then it will be interesting to see what happens to sails in the future as I suspect that the Wing Pocket will give a good advantage.. That is why Hang Gliders moved into to Double Surfaces, reducing Wing/Sail Area and increasing lift efficiency..
Ron
Finally the light has clicked on in someones head..... YES large luff pockets work better than standard luff pockets, Im surprised people havent picked up on it sooner.
The 'Sandpiper' yacht was made with a large tapered luff pocket which worked fantastically. (and they were around in 1984) I also used a similar sail a few years earlier.
NO you can't use a large luff pocket on a Class5 / Promo 5 as the specs actually specify the pocket size.
But the FISLY Mini 5.6 has NO restrictions on sail design.
www.fisly.org/rules/isrr.pdf (page 35)
I can't for the life of me see any restrictions on sails for the Mini 5.6...... Size, Shape, Construction or Luff pocket size ..... Someone will tell me if I'm wrong 
OK Gizmo! So what you are saying that the only LY's affected by the Luff Pocket Ruling are PROMO and Class 5? All others are cleared for the use of Double surfaces.. If the Luff Pocket is not limited to a size then as with some Hang Gliders they could be 60% of the total surface area?.. If FISLY and other Bodies do not get at it and stuff the reg's about first.. Any way, why have people not just gone ahead and created sails of this nature for the fun of it??? All-in-all, why is there not an open Class that can be sailed by all comers limited only by the course at the time?? i.e. If a Course is layed out at 4kms and isn't to tight for Larger land yachts then go for it. However if it is desired that only smaller LY's only should sail the tighten up the course and eliminate the BIGGIES or state so in the match regulations of the day..
Ron
Agreed the Standart system would constitute a wing section as there are in-fact aero shape formers / frames within the pocket.... therefore there are 'wing sections' fitted to the mast.
BUT a soft pocket (of ANY size) would / should NOT be regarded as a wing section in my mind.
And for those people who think a soft pocket is an aerofoil at what point does a mast pocket change to become an aerofoil shape.... 100mm, 200mm, 300mm, 400mm, 500mm.... when?
And isn't this the point of the Mini 5.6 class, being open design with minimum regulations.
