4 Meter mono foiler project

good work Doug, I will be using one, if you find the time to explain the way it works (I understand the idea, more the nuts and bolts of it) that would be awesome......

 

been a while

so, I ve been doing alot of work on this idea over the last couple of months since I last posted........

SR-71 formula

LOA - 4 meters
Rack Beam- 2 meters max
HullBeam At chines - 38cm min
Hull Beam At Gunnels - 76cm min
Beam At Rack - 2 meters
Trap - yes
One sail Only
11sqm
Max Mast Height - 7m
Max Boom- 2.5m
Max Luff Length - 6.3m
Open Foils (must be centerline mounted)
Min weight - ( hopefully only 5kg more than a moth, hull foils and wings. Haveto see what the proto comes out at and see what is realistic to keep homebuilders on par with boat builders if there ever are any.

Anyway, I am readdressing this because I got redirected here from the yahoo moth group because my posts are not mothy enough anyway, thats totally understandable......since last post I have got a quote from CST composites for all my wingbars, have decided on a CST HM 46mm Contender mast (46mm x 6.45 m), going to mount that on a 50cm stump (7m mast height overall). along with that a 2.45m eliptical boom mounted moth style (hinge joint). Been talking to Bill Hansen about a pocket luff sail of 11sm.. the hull drawings are almost done, so I will post them soon......can't wait to take the frame drawings to kinkos so I can get going on my mold. I again welcome any input.

 

Keep up your progress posts ...

I've been following your progress and it seems you are taking a similar path to the one I did. My singlehander's hull weighs 85 pounds, painted and varnished. My main is a little bit bigger - I went the 505 size mast route instead of the Contender. I figure it is just under 12 sq.M. I'm currently about 210, so bigger sail doesn't hurt me.

Had the main fully battened square top made by Ethan Bixby at North. Mast is stayed with spreaders, carbon boom and normal controls (vang, outhaul & cunningham). I tried to contact Bill Hansen about eight months ago about the main, but decided to go with Bixby because he knew the 505 geometry better (former world champ).

Since I'm not foiling I've got a 29er kite for fun downwind.

The boat ready to sail weighs in at 130 pounds.

Built mine with cedar strips waterline down, 3mm Okume ply panels above and stringer and frame substructure.

 

It's good someone else is interested, almost gave it up this week when all the mothies told me this whole idea was nuts, so now I've got to blow them out as well as my local A class guys just kidding, they are a very helpful group of fellas.....so anyway, I've recommited myself and hopefully after a couple more intense weekends of drawing it will be build time......cant wait to start making some sawdust on my new bandsaw. The hull drawing itself is basically done, at least I'm pretty sure it is, Just messing around with bulkheads and reinforcements right now... got some things I'm not that sure about, like if I use a stub instead of a mast step like on a moth, is my trapeze going to mess with the mast rotation, and if it is I should go with a regular stayed mast, but I will need to move up to a 7m mast and have to readjust my maststep reinforcment. I am also messing with my wing bars, I was thinking it would be cool to have them be adjustable so I could telescope them as the wind builds, have them adjust from 1.5 to 2m with maybe two points in between, but I don't know that much about telescoping carbon tubing, so I need to talk to the guys down at CST about that now as well....i go back and forth on the rig, I know I want a pocket luff sail, so thats not going to change, I can use that with either a rotating mast or a regular convetional one. I'll probablely end up going back to the original plan of using a Swift solo mast, then I don't have to tie the mast into the wings, and I can change them independantly if I have to. But I still need to find a good system for removable spreaders so I can slide my sail on and then connect the spreaders and trapeze lines.. I wish there was a RS600ff fleet in the US, if anyone out there is a RS guy, I'd love to be able to pick your brains alittle, maybe sneak some pictures out of you that and I still need to mess with the foils as well.....time to talk to Thomas Jundt and John Ilett.....back to drawing, i'll post pics soon........

 

Foiler

I'm interested-very interested,can't you tell? What you're doing is fantastic and it will be a great contribution to monofoiler design and construction in the US! Keep us informed-and yourself focused-best of luck!

 

You'll get a lot of weird looks and doubt from the club know-it-alls ... I sure did. Ignore them and keep your head relentlessly in the project. The last thing you need is third party generated analysis-paralysis.

From my experience, the more crap and trash talking people do, the less they have actually done themselves. People with real-world build experience realize pretty quickly that anything can be done, and that the biggest impediment to making something work is failure to try, fail and improve.

I've gone from "that guy who is obsessed about building a single hand skiff" to "holy ****, that thing really moves" , and I never would have got here if I listened to the majority of people's advice.

I've taken a Walmart barbecue cover, a mesh bag and made a structured spinnaker launcher tube that works incredibly well. I've take 3mm aluminum plate and make a boom sheeting system that works well (taken two revisions to get it right). I adapted a crappy big box store power boat cover and make a sailboat cover that works as well as a $800 custom cover. I've taken a junked bunch of parts and made a first class combo trailer/dolly.

There are no limits to how you can adapt and create quality parts from unlikely sources. There are also other things best done by people who really know what they are doing. The trick is to know what your own limitations are. Imagination can get you further than a checkbook.

Taking a hard look at the people who have innovated before you is really, really important. I can't thank Bram Dally and the SwiftSolo people enough for their development of systems for single hand skiff sailing. I've shamelessly adapted their ideas to work for me.

On a lot of things, go with your gut feelings and experience. Foiling technology is in it's infancy and there is nothing saying your wild ideas are any less valid than anyone elses.

 

thanks Bistros

Spent all weekend drawing, I have the hull drawings done and rendered, just need to do the hull frames and foredeck frame drawings, just finished the drawings for the deck frames, looks really good, I'm posting some as soon as I figure out how (learned rhino in 4 weekends, but I can't figure out how to work the internet) anyway, full steam ahead.....can't wait to start building molds, ordered MDF today My bewilderment has turned into "can't wait to blow past you"........The swift solo site is awesome, I go there all the time for Ideas as well, I was originally going to build a swift, but then I saw the foiler moth and the RS600ff and new I needed to become part of the foiling craze (little boats with one sail going very fast )....Bram is a real insperation...thats what I would like this Formula to turn into....a grass roots homebuild class, like the swift solo and the moth. I plan on e-mailing Bram once I get the proto done to see what needs to be done to make that happen. anyway, pics coming soon.

 

I like your thinking-most impressive. Looking forward to the drawings!

 

well, my wife says I've got that part down. I spend almost all the time I,m not at work drawing and redrawing on my computer, even till 3am sometimes, I don't even really know why..........but its addictive

And thank you doug for the encouragement........

 

at long last.........design pics








copyright Samuel Schneider Designs 2008

well guys, here they are, the hull is done.........sorry the rendering isn't that good, but I'm using a version of "RHINO" I'm helping develop for MAC OSX, and the rendering and export features still need to be sorted a little more, maybe by the time I post the pics with the racks, foils, and gantry.....

anyway, the boat is going to have an adjustable rack that gets joined to the kingpost, the kingpost will be what the mast and boom get mounted to and will be part of the rack, not part of the hull, just needed it in the pics so that I knew where to end the foredeck cone. This hull is 4 Meters LOA, It is 38cm wide at the chines, and the hiking deck is 78cm wide, it has long solid Cedar gunnels designed into the hull wings to spread the loads of the rack and the Skipper (when he is traping from the edge and standing on the deck in intermediate conditions.) it is pretty mothlike I know, but since the boat will be in the air more than in the water, it seemed like a good idea to have a hull that was as small as possible. planning on 1/4'' Foam core construction with a carbon skin inside and out, with extra layers of kevlar and 9oz glass on the deck for durability and protection.......it has a wave breaker bow like a formula cat, it looks cool and might help with getting to foiling speed faster in choppy conditions, improved windage, and slightly lighter weight for the same waterline......

 

Way to go ,Sam! Looks good.

 

Looks like you've really studied the Fastacraft/Moth guys and built upon their progress. Far more of a full-on foiler than I thought. I was expecting something more RS600FF-ish.

I have no doubt you'll get things working, just do not stop moving the ball forward. It's easy to say to yourself to forget things for a day or so and suddenly a month has passed. If you can;t get big jobs done, switch to a little job that you can, just so you keep the feeling of progress. I've found over time that making a little progress every week keeps the project from stagnating. Bet you foil before this time next year!

--
Bill

 

spent a lot of time studying moth build photo blogs, skiff build blogs and sites, asking questions to the yahoo moth group, and got a whole list of measurements from John Gilmore (Australian moth builder). I changed them around a bit to fit my formula, threw in a couple of my own ideas, and started to draw. Spent two weeks on paper with battens at the kitchen table, then started putting stuff into the computer. I know the learning curve will be much steeper on a design of this nature, but so will the payoff, I descibe it as "borderline stupid/cutting edge: ", Besides, once the hull leaves the water, its just a thing causing drag, the sooner you start going fast enough to foil, the sooner waterline beam stops mattering at all (as far as stability is concered). I went for a good compromise, If the RS600ff and Foiler moths are sailable, then I think this will be as well...



(to anyone reading this, I would love any feedback, if you looked at it tell me what you think....)

 

SR71 Foiler Stats (est)

Sam I did some work with the SA number you provided:
SA-115 sq.ft.
With a 160lb crew and the identical W/sa of a Moth with Veal onboard:
W/SA=2.558
Target all up including crew:294lb.
Target ready to fly boat weight:134lb.
Mainfoil area:
-to take off at 6.9knots boat speed=1.23 sq.ft.
-to take off at 6 knots boat speed=1.61 sq.ft.
-------------------------------
Rudder foil area is good at 50-60% of mainfoil area-same aspect ratio(7/1 good). You might consider building in a method to add short foil tip extensions
to the mainfoil only for improved light air takeoff. You can take them off for higher speed...
These areas are based on a CL(coeficient of lift) of 1.42 with a 20 degree down flap on a 63412 section. This is outside the drag bucket but would jump into the "bucket" shortly after takeoff.
This formula for lift was from Ray Valenga on foils.org:
S= L divided by[ F X Vsquared X CL]
----------
where S= foil area in sq.ft.
-------------------
L=.8 X [all up boat + crew weight] In other words, mainfoil load is 80% of total weight.
-------------------
F=2.09
-----------------
V squared= speed in MPH squared(divide this by 1.15 for knots)
-----------------
CL=coeficient of lift which I got from Abbot and Doenhoff.

====================================
Note on the wand: you do NOT have to use a bow wand! A wand can be designed to be integral to your board and retract when you lift the board up-without any attachment to the hull whatsoever.Used like this on Rave multifoiler. Very simple...

 

looks good Doug, only thing is if I end up with an all up weight of 137lb I'll throw the whole thing in the dump (an A cat weighs about 165, and if you think about it, thats like 2 sr-71's) ..........I want to keep it under 95lb, and closer to 85-90 if I can, 80 is my dream. less then that might be scary......(cst 46mm mast, carbon boom, all cst carbon rack, carbon gantry, foam/carbon hull,) should stay under 100 easy. the boat itself is not that much bigger than a moth, only 65cm longer, about the same freeboard, the rack is actually smaller (but some thicker tubing, so a wash), the boom is going to end up only 10cm longer (Hansen short foot technology) , 1.5m taller mast, 3sqm more sail (a wash since there is no wing tramp), and the shorter but stouter foils will probably be a wash as far as weight. if it ends up 60lb heavier than an average Moth than I did something very wrong

try it again with an all up weight of 90lb and a crew weight of 180 (average size trapeze skiff sailor with a harness on, this is a big boy kind of boat, not a toy ). (it ends up a 19lb difference or like 14%)

do you have any pics of this Rave foil wand?

Thank you once again for your input and interest.....


*****just got an update for Rhino OSX with better rendering, so real boat drawings with a hiking rack coming soon******