Slow work but I start to see some shape.

i was under the impression that lifting boards worked best when their section was an aero-foil style asymmetrical wing type

ie not symmetrical

somewhere on SA is a pic of the end bmwo's banana boards that showed a fat, high-lift, wing section

your build description for curved boards doesn't seem to mention a lifting section...???

straight boards can be angled to provide lift, but apparently they don't work well across a broad range of speeds so aren't used much

symmetrical curved boards aren't going to provide any lift are they???

Still looking for information any technical-engineering data would be welcomed. Are the boards on the A-Cats Asymmetrical?

I think it was pointed out in the commentary from the AC that curved boards is a way to improve performance so there is going to be development in the whole concept of curved boards in an engineering aspect.

Until then the old way of build and test will have to do. On the prototype I think I like Jake's idea of making a trunk that will accept both type of boards. Then I can tell which is best.

I believe the Flyer boards are symmetrical. Sym. sections do generate lift as a function of their angle of attack...most aerobatic airplanes have a symmetrical wing section and they fly just fine. An asymmetrical foil doesn't generate lift as well when inverted (which is why most aerobatic planes have a fully symmetrical wing). You do depend on your daggerboards to provide lift on both sides depending upon which tack you are on. However, the marstrom curved daggerboards, which have also proven to be pretty quick, are asymmetrical and conceptually mostly rely on the leeward board to provide the lateral resistance for sailing upwind.

So far as I KNOW in A-class, only the commercial Marstrom boards are assymetric. All others appear to be symmetrical, but there is discussion/controversy whether they can/should be canted forward to provide a positive angle of attack. Also there are several opinions on location: fore, mid or aft between front and rear crossbars.
IMHO, None of this is clear to the builders/experimenters. But you are allowed to buy a new A-boat for $US 25,000 based on your best guess!

Busy day I have the connecting beam plug fared and ready for epoxy & glass. Guess what starting to look like a hull need to match, fit, and build bulkheads.

few more...

lookin' great Mike!

I'm having trouble picturing the final shape of your beam you're molding...why does it appear to have such an irregular shape?

The beam is going to be an elliptical shape. I had some engineering done on the shape it is stronger then a circle or teardrop mast section shape. The beam will be low profile and will fit in a sleeve by design it will take care of twist so no pin is needed. Plus it is different and blends with the boat nicely; the designed connecting beams were funky. That is one reason I had more freeboard designed in the ama's to meet the beams better. I may build a channel and cut a groove in it to slide a tramp boltrope inside like a mast.

OK - I got it now. Thanks. It's also more aerodynamic too!

I figured it would help reduce beam slap from the waves.

Marking bulkheads.
I picked up this laser on a sidewalk sale at Harbor Freight last year it was good deal and figured I’d use it some time. I was going to use plum bobs to mark the hull then remembered the laser stuffed away in the cabinet.