If anyone wants a rundown on how I have built a fair few wing masts (and it's not that hard) just ask. It will be a lengthy thing without piccys, cos I havn't done one since I got a digital camera.
The plan would be for 3 vertical parts to the wing (like an aeroplane)
Main section at the front about 40% of the total area with a flap behind of about total 40% and a trailing edge of 20%. All individually adjustable to give the camber for the wing, ie fullness when slower and flattening as speed increased. Just a dream, but I think a mini would be ideal as it could be cantilevered (no stays) would only need a total area of about 3.5sq metres, not too hard to transport and the engineering is simple enough to be achievable.
Profile eliptical (like a Spitfire wing).
So far a plan/dream but as my son is going to be researching in the windtunnel it's worth a play!
Another simpler option. Use a spreder off a large water yacht. They are extruded aluminium. I believe they could handle being unstayed with a steel post inserted up the base about 1200mm. I had a rotating mast on my first homebuilt class 5. The mast post was 50 od. I just greased it up. The trick is the mast has to go over the mast post. With a mini the post would only need to be a heavy bit of tube somewhere arround 40 od.
Probably better than the spreader as per Clems suggestion is an alloy wing mast from an A class cat, but still way smaller than a foam mast. The A masts are about 150mm fore and aft, and drastically lighter than the spreader section which is usually 3mm wall for the smallest, going up from there.
Some wing data for your consideration. I have a Aclass section wing and sail set up of 4m that was supposed to to go on one of my early minis. The yacht capsized within 10m of starting off!. the mini morphed into "pigs might fly"., a 100kph capable 2.5m wide screaming kids terror yacht
in terms of area . I once fitted 3m wing to a CL5. it only ever got 1 opportunity to kill me, lesson learnt. finally consider this At 6m long and 4m wide , VINDICATOR carries a 4m wing,
Um , vindicator with a 4m wing is not only lower aspect that my minis, it isnt even as high!!!!!!!. AND it lifts wheels. do have a photo of the 2 together but wfey has archived it
Heres a Pacific Magic with a 4m wing /sail combo, just a bit too small for racing, but a brilliant concept for upwind. when this rig was put onto PIgs migh fly it just came too life
Gizmo, can you do your thing with the c of e thing on these 2 rigs please?
My offline has shown that the c of e on the wing rig is almost a full batten higher than the soft sail, and I am happy to be proven wrong! My reckoning on the wing rig about the batten below the remains of the lettering, the other the next batten down. Is that the remains of the sail off the old Sanderling that went to WA?
Remember Paul I have also sailed Vindicator. and you also will have taken into account that the c of e is not only of the rig, but how high off the ground it is.
It's always going to be higher with a bodied yacht, cos the base of the mast is on top of the body. Consider the difference on the Pac Magic, and "Pigs Might Fly".
At a guess using the wheels as a guide, the mast base on the PM 15" off the ground, on Pigs at least another 12" ?
Vindicator has a nominally square top, the c of e goes towards the tip, and from memory when the axle has not loaded up the base of the mast is a couple of feet or so from the ground?
If my stability theory works (and it has for me) then you can't just compare the rig lying on the floor, it has to be considered where it is in relation to the roll axis, which is at ground level. So where it's mounted on the platform has an effect.
Heres ths line pic... The thing with wings is its the mast thats doing a lot more work and the line drawing would be a hypothetical.
Also a wire stayed mast twists/ rotates froward which would move the CE forward quite a bit.
Several months ago there was some discussion on the forum...
www.seabreeze.com.au/forums/topic.asp?TOPIC_ID=46374
I had a chat to a guy recently that tried a padded sail on a sailboard, he said "good when it was dry but once the sail was in the water it couldn't be lifted out" due to whe water in the foam in the sail
Here is another version of a padded sail that might work on a Mini landyacht....
www.pdracer.com/sail/unusual/
The Pig yacht looks like it has a much wider springy wooden axle ............and the pasific magic yacht has the boom connected much further back on the wing-mast than the Pig yacht. Also the height. Height to width ratio, i.e height to CE/width of yacht. A class 3 with a 7m high rig is no more 4m wide. So a mini wing could only be 3m high. To get the takeoff down wind it could be wide, like those short windsurfer rigs, but with a 250wing in front.
I know nothing about wing masts but would like to know more.
Padded sail as in the link Gizmo showed.
When I was in Europe I had the dubious pleasure of sailing a padded sail on a class 5 for John Glen (before the rules were revised) This was one where layers of soft foam were on the surface and cover with sail cloth. Being John it was very nicely done, the foam had been hotwired, yes it can be done, stinks like hell and very unpleasant but.., and all stuck together with "Evilstink" (Evostik).
We used this on the yacht which Faze 5 built for Mark White, but the little wheels on a soggy French beach killed it. It went like wotsit off a stick on the airfield though. It was then used with the famous strings on a Glen5R and was much faster on both surfaces.
Then of course because I was the guy who used it almost withiin the rules I was drafted onto the rules revision group! Now it's definitely not legal on a 5.
Would I use one on a Mini? Don't know, transport was not easy as you have a 5 metre long sail which you cant fold!
Kiwi, I would have to agree the method that I use for finding the CE is only VERY basic and doesnt take into account of current larger toped sails, Im interested in looking for a better way to accurately do it though.
Just a thought in cutting soft foam rubber, isnt that the stuff that is used in furniture that has toxic fumes when burnt? So the Fire Dept says.... and by the smell of the stuff I believe them. (so if you are going to try it....use a fume mask OUTSIDE on a windy day !!!)
I agree there has to be a better way of working out CE than a cardboard cutout and a plumb bob or the way im doing it.
Can you imagine NASA or the BOEING factory with just cardboard, bits of string and paper planes?.....
Fitted the mini sail to my class5 today to see how it looked. Still have a lot more hand sewing and the battens have to be cut and tensioned it looks OK but not sure how it will go ( as you can see by the battens I cut plenty of the sail ,the long one was the bottom batten). Bloody weather has held up fiber glassing the seat
Cheers
AUS230
Nice to see Spring has arrived at last!. I am looking forward to getting some SEABREEZE at Ohope soon.
this is starting to look like a race!
Hey kiwi, I seem to recall going into john glens front door was an environmental hazard in its own right
Getting close to finishing mini beast, a couple of seat brackets and rear pully attachment to fit then strip and paint hope I get it finished before the long weekend at Lefroy, Its going to take a month to clean my shed after this exercise had to do all the sanding is there because of rain.
Cheers
AUS230
Finished mini beast today except for boom tail. The weather has been against me There is a big size difference