nacra 6.0 na 1997 yr :: Catamaran Sailboats at TheBeachcats.com

Tuning The 6.0 N.A.

StartingPoint:Hull Alignment
Since all NA?s are brand new (out of the box), start with the front crossbeam and set the hulls at the stops. Set the rear beam in the saddle & adjust the the movable stops to allow the hulls to be aligned. The NA tramp is designed to tension only from the rear beam by shimming the stops at the front beam. Set the alignment so there is no toe in or out. Since the NA has a front foiler instead of the bridle wire, alignment does not change with the rig up.

Rudder Alignment
Rudder alignment should be set to 0 or 1/32? toe in to compensate for lash in the rudder system. Set the rudders after the tramp is installed and tensioned to make sure the hulls are in final position. With the sleek hull shape of the NA rudder alignment becomes even more critical than on other boats.

Daggerboard Tuning
NA Daggerboards and rudders are the same as those of the 5.8 so careful tuning is important to prevent cavitation. Rounding of the leading edge seems to be more important than getting the trailing edge sharp. For the trailing edge, thinning of the foil from about 1?-2? forward to an edge about 1/16? thick seems to work best.

Mast Set-up
Set the spreader rake to about a minimum of 2?.(Place a straight edge across the tips of the spreaders and measure to the back edge of the mast) With the double diamond wire system of the NA mast, it is important to use a wire tension gage to set the tension of the diamond wires. Start with the outer diamonds and set tension to about 500 lb. this should result in the mast being pre-bent about 13/4?. Then set the inner diamonds to be just tight but not enough to increase pre-bend.

Bridle Foil
The front foil should be tensioned to pre bend about 1-1/2? new and not allowed to relax to less than 1? of pre bend after the rigging has settled. This has no effect on speed and is strictly a strength or durabilty requirement.

Rig Set-up
We tried several positions of mast rake and found that about 15?to18? of rake seems to be fast upwind without creating excessive rudder load or de-powering the boat. We measure rake by pulling the trapese harness hook down and moving it to the point where it just touches the top of the deck forward and aft of the front beam. Then measure the distance from the center of these two points to the front of the front beam. Shroud tension shouldn?t be too tight to allow full rotation of the mast downwind.

Downhaul System
The stock downhaul system [8 to 1] is adequate for the stronger crews. The leach of the main will open up readily with the application of downhaul. Because it works so well it becomes the sole method of controlling the main on wind gusts.

In Conclusion
The 6.0 NA is a high tech around the
buoys racer that must be properly tuned to be competitive (with other NA?s). I believe we have only begun to tap the speed potential of this great new boat. If you have any questions or comments please feel free to contact Mark .

Mast Setup for the Big Guys
Spreaders should be set to 11/2? of rake. tighten outer diamonds for 11/4? of pre-bend. tighten inter-diamond wire just short of inducing anymore pre-bend.Note: under no circumstance let pre-bend to go under 1?
Please note; Final measurement of the pre-bend, should be made with mast lying on its side!
mast rake? (most accurate) level beams fore-aft, hang a weight from the main halyard weight should hit the tramp appx. 15 to 18? aft of the inside ( tramp side ) of main beam.
Do not over-rotate mast down wind in heavy air!

Carbon mast, so far this seem to be
what works. The tube has all the same fittings in the same place as the aluminum section. Follow the same guide lines.
Update Carbon spreader rake to 2.75?
with prebend approaching 2.0? with inter-wires loose.

Heavy Air: do?s & don?ts
Don?t over-tighten shrouds.. adds to mast compression
DO release jib in a puff before dumping main
Don?t remove spreader rake!
Don?t over-rotate mast.

<< April 2024 >>
	S	M	T	W	T	F	S
>	31	1	2	3	4	5	6
>	7	8	9	10	11	12	13
>	14	15	16	17	18	19	20
>	21	22	23	24	25	26	27
>	28	29	30	1	2	3	4

nacra 6.0 na 1997 yr

Users on-line

Search The Beachcats

Upcoming Beachcats Events