Jake,

I hear ya. The reason i need to bring the pole all the way back is to bring the loading securely back to where it is originating, at the back beam attachment point for the understay.

This is more a safety measure than anything else. Keep in mind that because of the pretty severe angle (i didnt dare drop the DS any lower) there is going to be alot of tension on the y-axis to get enough force down on the Z-axis. when i say alot, i mean upwards of 800+ lbs. I did not want this to simply be absorbed by the front beam, the flex from the beam alone could make tuning a bear. Instead all that force goes down the central member, to the origination point of the loads. That way it keeps the "collateral" y-axis forces isolated from the rest of the boat, and rig, while retaining the z-axis loads placed under the forestay.

Check out the GC32's, or the AC45's they did the same thing, for the same reason. with the small exception of using carbon.

I had not thought of getting trapped. perhaps i can have a sleeve sew into the tramp...


as for the lawnmower, i plan to attach a 30 foot articulating sprit to the base of the mast, supported by a boom and truss system tied to the mast head, which allows 360 degree movement using an electric motor and swivel. The "chopper" will automatically engage at the 1 minute gun, clearing a 30 foot circle around my boat, and guaranteeing me a slot to leward at the start. but i'm in touch with RC to see how this will affect my D-pn.

That thing (the second picture) definitely looks like an EC winner

Aluminum 4 OD X .125 WALL (3.750 ID) 6061-T6

a good deal thicker than stock tubes, which i measured at just under .08 wall.

I couldn't find confirmation of what grade Nacra uses, but considering the marine application, (corrosive resistance essential) and the fact that the integral kedar rail is welded in (machinability/weldability essential), i have a hard time believing they use a 7XXX series alloy which is stronger than my grade. -Most likely they used a 6-series T6 like i am. of course 6061 is the stronger end of the 6-series spectrum.

-I would've liked to go a couple hundredths thicker but it was .125 or .250, no in between. .25 would have been just stupid.

I did do my deflection rate calcs on the beams and i believe it looks ok. That being said, as a matter of principle, i will not be having 2 guys on the wire, ever, and this whole thing is designed as a singlehander, meaning just my 200 lbs to contend with.

"Is your forestay pinning directly to the pole or will you have bridles?"

Neither. It will attach directly to the understay via a piece i am machining. The piece will pass through the center of the pole vertically. pics to follow.

as for the lawnmower, i plan to attach a 30 foot articulating sprit to the base of the mast, supported by a boom and truss system tied to the mast head, which allows 360 degree movement using an electric motor and swivel. The "chopper" will automatically engage at the 1 minute gun, clearing a 30 foot circle around my boat, and guaranteeing me a slot to leward at the start. but i'm in touch with RC to see how this will affect my D-pn.