Fittings
We took care of every detail in Nano's design. All fittings are made of stainless steel AISI 316 which ensures the absolute corrosion resistance. Every fitting is designed with the use of the latest 3D software. Cutting of all the details is done with a 5-axial laser.
For the absolute reproducibility of all bent elements, we use numerically programmable benders in the process.
In order to sustain uniformity of welded components we use stainless steel AISI 316L as a binder. When welding parts together, we use the TIG method in argon environment. A steady hand of our experienced welders guarantees uniform and aesthetic welds. At the end of the process all the fittings are pickled in a special mixture of acids to remove any surface scales and stains.
All rivets used in Nano are sealed and acidproof with a pre-prepared controlled swelling area. Additionally, a pre-formed crumple zone of these fittings provides very good strength parameters of all connections. The tightness of all used rivets makes the mast unsinkable during a potential dump.
All stainless steel nut rivets used in Nano are also sealed and acid-resistant.
Trampoline
Experienced sailors know how a good stretch of the trampoline is important for the smooth movement on the catamaran's platform. In Nano project we designed beams and side lines of the hulls so that all four lines forming a trampoline make it one perfectly flat surface. Nano's Trampoline can be individually strained in any of the four directions.
Nano centerboards. Profile.
When designing our new centerboards we focused our attention on selecting an appropriate profile thereof.
Considering the fact that in majority of circumstances centerboards operate under transient flow, we decided to apply well proven profiles which at low resistance throughout the entire range of velocity provide high efficiency and are highly resistant to breaking of stream.
In the "vertical" section of the centerboard we have applied the NACA 63-012 symmetric profile which ensures generation of appropriate side force both at small and large speeds while at the same maintains appropriate rigidity.
In the carrier section this profile turns smoothly into a non-symmetric NACA 63-412, passing through all the intermittent profiles: NACA 63-112; NACA 63-212; NACA 63-312. It must be noted here that this profile is capable of generating adequate lifting force as early as at 0 degree trim.
Apart from high efficiency proven by computer simulations, the NACA 63-412 profile performs perfectly well also both in the large and ultra light units equipped with hydrowings. The choice of the NACA 63-412 profile constitutes and ideal consensus of low resistance at high speeds and generation of high lifting force in the entire velocity range.
Nano centerboards. Shape.
WingFoX Nano has been equipped with centerboards of variable curvature and variable profile.
Since class regulations restrict the area we can use to generate the lifting force to 40 cm, the shape of our centerboards was designed to take maximum advantage of the area available.
The geometry of the centerboard was designed so as to allow the lifting part to generate lifting force even when the centerboard is partially drawn out.
The asymmetric profile used in the lower section of the centerboard generates lifting force already at zero trim. The centerboard box and the elements contained therein permit centerboard trim within +/- 5 degrees of the angle of incidence of the lower section of the centerboard.
The centerboards feature increased length to allow them to work deeper in the events of more stabilized conditions. In the surface layer we encounter rotating currents, a rotation of water masses, which impairs the efficiency of a centerboard.
Assuming appropriate lifting force to be generated by the centerboard we took every effort so that a lifted up centerboard could still generate adequate side resistance necessary for the boat not loose its capacity of sailing upwind.
What happens in the case of centerboards having constant radius of curvature is a considerable loss of lateral surface of resistance, which causes increased leeway and makes upwind sailing impossible. In extreme cases the loss of upwind sailing potential may not be compensated by higher speed.
The special design of the centerboard box allows its easy raising while maintaining tight fit in every position.
Nano centerboards. Technology.
New centerboards WingFoX Nano are made entirely of carbon prepreg. We do not cover them with a layer of topcoat so the run-off edge is very thin though also very tough. The entire element is hardened and annealed in an autoclave.
Due to specially designed internal structure it was possible to give up the use of filling foam and glue to fix the two parts together.
The centerboards are made in a single process technology and thus are monolithic, which ensures their high rigidity at minimum weight.
Special array of carbon fibres, accompanied by appropriate design, yield a significant increase of rigidity. We have put much effort to the selection of centerboard geometry and its rigidity so as they would not cause vibrations. We have paid particular attention to the forming of "higher harmonic vibrations" which are periodically appearing oscillations whose frequency is a multitude of their free vibration frequency. What results is an uncontrolled amplification of the amplitude. In extreme cases it results in breaking the stream flowing round the centerboard and a sudden drop of the lifting power. Windsurfers are well aware of such situations when suddenly the centerboard looses its capacity of generating side resistance force and a spinout occurs. Apart from lower efficiency, an oscillating centerboard causes diffusion of energy and thus generates increased resistance.
Centerboards require high precision of workmanship. That is why we have applied the CNC technology to make centerboard forms. Specialist software allowed us to optimize the lifting power in relation to the resistance.