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August 28, 2013

Yrvind shows the rudder system of Yrvind Ten

The sound is a bit weak, please increase the volume on your computer.




August 24, 2013

Details

The idea of using ridges to guide the centerboards up and downhaul did not work to my satisfaction.

The new aproach is to use fairleads. I made up a few of carbon fibre. Click once or twice to enlarge.

Before I glued them on to the centerboard case I dusted the surface with cupper powder using a salt shaker. The purpose is to reduce marine growth and to make the surface a bit more wear resistance.

Below is the fairleads in place.

I will make new rollers with a hollow in them so that the line are keept in the middle and be less likely to jam. A jammed line is no good.

The rudder arrangement is now working to my outmost satisfaction. Only thing is the stainless steel structure is far to heavy. Therefore I will make a new one of composite surfaces, keeping the same geometry.

Once I had that thought I realised that the new structure can have the shape of a tank. A closed surface is strong.

The use of a tank way back is to fill it with saltwater running before gales. The yellow 15 feet boat I 2011 sailed with to Martinique had mowing ballast in form of lead. I could move them from side to side but also to the very back of the boat. It was a good idea.

It also struck me that in heavy rain I could collect extra water to do some washing when the sun later comes out.

Also it could cive some extra flotation.  The platform is bolted on and therefore its lenght is not measured according to the harmonized standard of the EU:s Recreational Craft Directive, besides few things are more stupid than measuring a boat by lenght, or in fact any volyme by lenght except if they are of the same shape.

I take care to make the details good on this boat in order to have experience of them and use them on the next proper small boat.

To be continued…

Regards Yrvind.




August 1, 2013

TWO STEPS BACK.

The ropes in the centerboard did not run smothly so I am working on an other much better system. More about that later.

The rudder system is also being uppgraded. When I designed it I had in mind the boat sailing to windward healing 20 degrees so the rudder axis is 20 degrees out to compensate for that and also 20 degrees slope that they will not catch seeweed and other things . But – my rudders will also serve as brakes instead of a drouge. I just angle them outwards. Now I realised that that will give lift to the aft helping to pitch pole the boat.

The outward angle is now reduced to about ten degrees becouse that is better downwind and the aft to about 5 degrees. Tan for 5 and 0 degrees are nearly the same in this context. Of course it would be even better to angle them forward becouse that will suck the aft end of the boat down but that has to be balanced against catching things. It is a compromise.

Also I widened the platform 18 cm and lengtened her by 5 cm to enable me to have a longer tiller and so that the bathining ladder will not interfere with the line system.

The pictures below show before and after the change. The new line arrangement is not shown.

after change

To be continued…

Regards Yrvind.




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