As some have commented, I seem to have done a lot of fiddling and moved away from Juan's published set up notes, however as I said, my goal was to get the booms parallel to the deck with the aim of reducing windage which means you have to rake the masts and therfore .move the centre of effort of the rigs aft and have to do the same with the fin. Having faffed for what seems like ages, I now seem to have a boat that performs very well and I hope to be competitive at the next ranking meeting with 40 or so boats. Certainly recent club racing has shown the boat to have a marked increase in performance
I list some of the key measurements below for those interested. Of course I have a way to go on my Alioth journey but these numbers may help people with the raked rig set up.
Fin
Leading edge of top of fin to bow (excluding the bumper). 500mm (measured parallel to the waterline).
Craig Smith fin with robot bulb and John Gill rudder
Fin leading edge is raked 92 degrees to waterline to offer neutral to lee helm. (I have an insert which gives me a fin angle of 90 degrees which takes the bulb forward and is excellent for light weather as it brings the bow closer to the water)
Bulb angle to waterline 1 degree. I adjust the angle by using bits of cable tie in the bulb channel
Hull to top of bulb down leading edge of fin. 330mm
Bow behind bumper to tip of fin where it enters bulb 637mm.
Bottom of bulb is 2mm above the max draft measured in a tank.
C of G of bulb is 5mm forward of leading edge of fin
Depth of rudder 220mm. Very thin chord but no experience of stalling and great when nose diving downwind.
Rig
Top of boom band to step 135mm
A rig mast rake 1040 (bow behind bumper to 900 mm mark on mast measured from top of foredeck.)
The objective was to get the boom parallel to deck to reduce windage upwind as well as getting the centre of effort as low as possible. It is the same on the B and C rig.
Sail setting are similar to those quoted previously within this web site.
My only developments going forward are to perfect a better mast pre bend for the A 15mm and B rigs 10mm. My current A rig has a slight kink where I added extra prebend. The secret is getting a smooth bend which I find hard to achieve whether I use rollers or bend by hand
My goal is to set a straight mast under tension with flexibility to achieve a max of 10mm even bend.
Time will tell how it all works out.
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