Tuning: NACRA F17
Nacra F17 Carbon Mast Tuning Guide. Effective date: June 20, 2008
The information provided comes directly from years of testing and sailing.
By Bob Curry, 2004 / 2007 NACRA F17 North American Champion
Rudder Alignment
Rudder alignment should be set to 1/32”to no more than 1/8” toe in. With rudders down andlocked, measure fore & aft on the rudder, 12” down from the bottom of the lower castingandlevel with the bottom of the stern. The tiller arm to cross bar space should be equal on both starboard & port sides before tightening the set screws.
Daggerboard/Rudder Tuning
Careful tuning of the daggerboards and rudders is important to prevent cavitation. Rounding ofthe leading edge seems to be more important than getting the trailing edge sharp. For the trailing edge, thinning of the foil from about 1” forward to an edge about 1/16” thick seems to work best.
Daggerboards:
Upwind:
- Skipper sitting on the side> Boards totally down.
- Skipper hiking almost on trapeze > Boards totally down.
- Skipper on trapeze > Boards totally down.
- Skipper on trapeze and full cunningham > Raise the boards 6.0” up above the deck.
Downwind:
-Always raise the leeward board about 12.0” up above the deck and the weather board all the way leaving just enough board down to fill the trunk below the hull.
-Mast rotation always fully opened/released and enjoy the ride!
Rudder-rake/angle:
You turn the adjustable eye that is screwed into the lower rudder casting 1 ¼” out. You measure
between the black rudder case to the center of the adjustable eye. This is a good starting point for most skippers.
Mast Set-up
Spreader-angle:
With 175 lbs on board, recommend that you use 2 1/2” of spreader rake.
With 187 lbs on board, recommend that you use 2.0” of spreader rake.