Tagged: DF65 tuning
30 November 2018 at 14:40 #1771
Posted by Kyle – January 2015
After having some real issues by not finding a logical way of removing the snap windward helm that I have had on my DF65, I decided to re-cut the main with a smaller curve in the luff. My main was the first effort of mine, and each one since had a smaller curve, so my new one is the same as all the ones I have made since.
In talking to Ron at the Dam last Wednesday, he mentioned about a few measurements for example from the transom to the top of the mast amongst others, which I hadn’t heard about, so I took to Google last night to see what I might be able to find.
I found two articles, which I will add below with two separate “ideal” measurements from the respective authors. Most are pretty close, and it was a first for me to lay the yacht on its side to measure sail twist from entry point. After today’s sailing, I must say that it was a great starting point for the yacht, and today’s sailing was from last nights set-up without adjustments at all through the day.
I ended up 1st or 2nd in each race, so it was nice and consistent, with some good power in the sails. The words from the authors are below.
Oh, and by the way. The snap weather helm has also disappeared completely, and the yacht seems to be quite neutral in its set-up now. Possibly need a little more wind though to truly test that.
Main boom angle: Sight from the back of the boat, and the end of the boat should be just inside the drain hole.
Jib boom angle: 45 mm from inside of jib boom to side of mast.
Jib twist: First off, mark the back of the leech with a pen at half distance from the clew to the head and measure from that mark to your topping lift. Mine was at 25 mm.
Main Twist: Again, put your mark on your main leech half way up. With the boat on its side and the main trimmed to sail upwind, measure from your mark to your backstay. Mine was at 45 mm.
Jib outhaul: 17 mm at deepest part
Main outhaul: 20 mm at deepest part, but it’s hard to judge.
Jib cunningham: None.
Main cunningham: None.
Backstay: No pressure on it. It’s only use is to keep the rig in the boat!
Bridle: MUST be centered. I lied about not touching my boat all day. Before the start, I found I was good on one tack and not the other. My bridle was about 2 mm to one side. The boat is VERY sensitive to this.
Forestay: Not tight, but not flopping.
Mast slide: Centered
Obviously these measurements vary as well depending on wind conditions, velocity changes,, water conditions (waves chop, or flat), i just took my measurements which seemed very fast compared to the other DFs (Condition 8-15 MPh, big rolling waves, big velocity shifts) . My measurments on Boom angles: main/ 8mm pointing at inside of transom jib / 35mm inside mast to boom , Twist : main /60MM 2nd batten to backstay, jib/ 25mm to topping lift Foot : 20mm Jib 18 mm main ( recently started carrying more jib foot than main) Rake: 980mm Transom top to top of main swivel , Jib boom 15mm off deck to bottom of boom, My mast slide has stayed in the middle (need play with this more)Generally speaking you want to follow general best practices whn tuning the boat : Sail twist on main and jib should match, Im sure there are better tunes out there but this seemed fast for me…
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