Friday, July 10, 2015

Fila 89 - technical details

Fila 89 is the second fila boat i built.
The goal was to improve the sailcarryingability while maintaining the excellent handling of the boat.

The the original fila handles as good as any of the rc sailboats i have sailed, and still sets the standard for comparison for me.

The new boat has the mast and the keel box set further backwards to compensate for the expected bigger rigg, and longer keel.
The goal was also to sink the stern at heel angles bove 25deg(with the weight further aft and the big luff), lifting the bow. Giving it the ability to jump waves, reducing the entrance angle and improving agility.

It is not finished yet. It has a rigg and keel borrowed from evolution. Later it will recive a rigg identical to evolutions.

But the keel will be different.

The rudder is the same as evolutions.


The keel is 58cm long from the bottom of the hull to the bottom of the bulb, the bulb is 700g the keel 140(too much, but hey its aluminium)

Some diy stuff, 2.5mm allen key makes sure the backstay clears the sail and the boom

Why plastic sucks, the wang is loosing colour, and the right-most piece is bending despite 100% infill

the jib pivot is set further furward on this boat. The idea is to get the sails more paralel. This way the jib should depower later while keeping the desired gap at the back of it. And the ce doesn't move as far back when reaching(a better explanation would be that the jib remains more sheeted in, but the gap to main is still the same, the jib is more parallel ti the center line).
This is the best change compared to other boats. It makes bearing away much easier!, and smoother, there is no need to depower the sails all the way to the top of the riggs wind range.



This ,aom/sheet-servo position is a first for me. and it will stay this way for boats to come.
There is much more "hand space" inside, but it is a pain to change servos...  
note: 3d printed servo arm(seems to hold the 17.7kg@1cm@6V for now, it is 8.5cm long) and mount


3d printed mastbox and rudder servo. Positioning of the servo is not ideal, but the woodden support was to narrow for longitudinal mounting. The link is just temporary.
Note: this boat uses only stainless steel fittings and screws, the hooks for the stays are 1mm tig welding wire, the screws m3 stainless, whatever lenght is required.

I managed to loose the little 10mm tube that slides over the mast crane to extend it. Recently someone said that zipties are a temporary lifesaver. But all life is temporary they say..   ..mening this should break soon.




When i recieved the hull there was a big hole where my jib sheet outlet/hook would be. This flying hook/outlet the idea came from some beach cats and fireball dinghies, it is accompanied by the "standard" jib pivot tensioner.

Sailing tests concluded that the boat is floating on her desired static waterline(probably with a dispalcement of 1600-1700mm3), i have yet to weight her.
It also needs a keel with more surface, or more lift. since it sometimes goes sideways when not at ful sailing speed and it drifts quite alot when standing still.

I have a special keel planned for this boat, one with area concentrated just below the hull, and a strut hanging from it deep in the water. Similar to mal smiths boat here:http://www.users.on.net/~malcolmandjane/750.html

A post with sailing photos follows.





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