New low-cost "hardware store" racing class; input on proposed rules

So we are currently heading north on the I5 and will be back in the PNW on Thursday. Does anyone want to meet up to discuss designs? if so where/when?

I have now made a model of my Zest dinghy, I'll post photos next week

http://sailingcatamarans.com/index.php/designs/1-beach-cats-and-dinghies-/436-zest

Richard Woods of Woods Designs

www.sailingcatamarans.com

 

Ill be home in Gig Harbor. If you are driving through Tacoma on Thursday, call me and we can meet.

If not call, or text and we can meet somwhere at some time. Where are you stopping, Port Townsend?

 

I have never seen a gybing board that worked in practice, so that was out. I have patents for variable camber foil surfaces, but all are complicated, and probably not practical for a 'Hardware' sailboat.

The real reason is i would like a completely clear flat floor for sleeping on Raid type events, cruise camping, etc, my daughters requirement. I would also like a clear space for the 'Chilly Bin/Esky/Cooler" to be stowed optimally. Someone did sugest we explore diferent ideas, ones we have always wanted to look at.

However if asked, i will go on about the need for the top of the dagger board to be immersed at all times to avoid drawing air from the surface down the low pressure side of the board causing cavitation, and increased drag etc. When exposed, the upper end of the daggar board also loses its end plate effect.

The latest 'Review' this weekend, complete with out of state consultants etc, showed considerable advances in built items, and even more progress in sucessfull experiments for other items and components. Pictures will emerge eventually.

 

Alan,

Would you be willing to show your patent numbers for variable camber foils?
I have always been interested.

Marc

 

Alan: I'm sure a lot of us would be interested in seeing your ideas for variable-camber foils.

Why not start a new thread to describe them? Since you have patents, you should have nothing to hide.

 

Your application probably does not cross over well, but we are definitely interested.

If I was better at fabricating and/or more willing to spend cash, I probably would have started work on an idea I previously worked on. The better part of the discussion starts around post 75 of http://www.boatdesign.net/forums/hydrodynamics-aerodynamics/what-significance-wing-thickness-45383-2.html#post619208

A concept that I think has merit is a "fat but high aspect ratio" wing more to the rear than typical with more than normal soft sail up front. Close to an aft mast arrangement. For a really small tri, a 2' cord wing is should be easily manageable by one person during boat assembly.

An alternate version of this concept is a carbon pole up front that connects to the aft wing . With a good luff pocket jib, the combined rig should all be very light, very clean areo, very low stress and only require side stays.

 

Richard was suprised at our 20lb @ ~$20US mast. Here is a cartoon of the cross section.

Cut and laminated from selectrd fir, few or tight knots, and with upper mast taper, this should weigh ~20lb, and cost ~$20US.

This is too heavy for us, so a new cross section with superior aerodynamic performance, thats lighter, and cheaper was discussed in last weeks meeting.

 

Richard,

You asked about Dagger Boards and their placement.

Here is a screen shot close up of the daggar board cases, and their position. I plan only two frames/bulkheads in this boat, none support the Dagger cases directly. You mentioned your having 5 frames, presumably including stem and transom. In my case, i have a stem and transom, but only two other frames. Marc, this is a stringer centric structure, with 4 longditudinals in the 'flat' bottom to retain shape. These longditudinals have upper and lower caps, and plywood webs. The sides may also need stringers. The plywood chosen has better lateral support than longitudinal stiffness.

The second screen shot shows the hull on its proposed building frame.

 

Maybe it's my fault, but I really struggle to see how a 2' chord wing mast could drive a small tri or anything else very well. Certainly the various efforts at small wings on Sunfish, kayaks, small cat test platforms etc that I have shown no evidence of performance that can match a conventional rig.

I'm always interested to see how slow high aspect rigs can be in many situations. One case in point is the OD International Canoe, which has a longer and narrower hull than the Laser, much more sail, similar WSA, a much lower DLR, and no more speed than a Laser downwind in the light stuff when the Canoe's high aspect rig stalls out.

The same thing is noticeable in cats - the high aspect rigs are not at all fast square running in the light stuff and low-aspect rigged cats (Hobie 16 etc) and slow trailable yachts and dinghies are depressingly hard to get away from.

Sure, high aspect works in terms of all-round performance in cats and Canoes, but only because the other aspects of their design allow them to generate more apparent wind and righting moment.

 

No one in his right mind runs a beach cat square down wind.
It's not worth talking about if you don't know the facts.

 

I was using "running square" as shorthand for sailing down the leg from the top mark to the leeward one without going past any wing mark, just as you were apparently using the term "beach cat" to denote performance cats with high aspect rigs such as A Class cats and F16 types.

Sure, you don't run 180 degrees to the true wind on high performance cats, but then again you don't run 180 degrees to the true wind on a Laser either and yet 'round here no one accuses anyone of ignorance if they refer to "running square" in a post about Lasers.

 

CT249 : If you allow the International Canoe to tack downwind at its optimum angle, do you think that it would still lose to the Laser?

 

More obfuscation and fact twisting from CT; (saving key strokes and electronics ... LOL), if you write running square you're meaning flat off (which no one does except those in old dunga designs) but running square means that ... running bloody square. You're making me sound as pedantic as yourself.
How about the "square leg?" Two words. Saved a few electrons there, right?
And what is this BS of beach cats and 18s not being beach boats, when they, in fact, are - although admittedly, more carefully handled and pampered ... but still launched from shore ... or beaches. Holy defecation.

 

In my experience in light winds the VMG is similar when each is sailing at its optimum angle in light airs downwind, and multiple world champ Steve Clark and others have noted the same thing. The

EDIT - I haven't raced the new rules boats (hence the reference to "OD International Canoe" in the earlier post) so I'm not sure at what windspeed they start to tack downwind at high angles and how they relate to the Laser.

 

Gary, what you are missing in your lust to throw hate and abuse around is that your post is just more evidence that things are described in different ways in different places. "Flat off" isn't used around here, nor is "dunga", but you don't get abused on BDF when you use those terms.

Sure, in the US they call lots of fast boats "beach cats", but here "beach cat" has often been used as a way to distinguish a centreboardless production board in the Hobie 16/Maricat/Surfcat style from a centreboard cat like a Formula 16, Mossie or A Class. That's the point, not all terms are used in the same way everywhere. As another example, in the UK some people call cats "dinghies" whereas here in Australia that's basically unheard of.

Yes, you can launch an A Class from a beach - so what, there are places where they launch Flying 15s, trailable yachts and 18 Foot Skiffs off the beach and not many people call them a "beach yacht" or "beach skiff".

And what in the world does this have to do with aspect ratios anyway? I was simply noting that high aspect rigs do not perform particularly well when trying to generate the best VMG for going close to dead downwind, rather than going downwind doing the wild thing/sailing hot/sailing high angles/whatever you want to call it. Not even a Laser actually does dead square when sailed properly!