The lug sail is not attached to the mast by a track, only by the halyard. The pull varies at least 270 degrees. To utilised all of the mast the Ex Lex halyard comes out at the top of the mast at the center.
The diameter of the Dynema halyard is 6 mm the hole is 10 mm diameter.
Previus experience with POM aka acetal and Delrin has shown that it does not hold up to extensive wear. I therefore chose bronse even though it heavier.
Below are some pictures.
The first sketch.
In the lathe.
Ready to be cut.
The finished product. Its conical on the outside as well to save a bit of weight at the top of the mast.
Ready to be tested with the halyard. The mast is the bottom part of Eurupe Dingy masts, donated by Marstr├Âm.
I do not have inside halyard. A small piece of bent titanieum reduces wear on the carbonfibre.
Silicon rubber is inserted to create a epoxy tunnel.
The mast are standing upside down. Me injecting epoxy above the fitting, embedding it.
After the the NM-epoxy has set the silicon rubber is pulled out and leaves a nice tunnel for the halyard.
This way of raising the sail takes more force than using a system with a pulley, because of friction, but the sails and spares are so small that its OK.
On the other hand its creates less compression on the mast (becouse of friction) and it has no moving parts and is omnidirectional so not much should go wrong.
To be continued…
Here is a 15 min video showing Ex Lex. It will be boring for people that do not speak swedish. It does however show the boat and me crawling around in it.
It was shown at the G├Âteborg Boat Show Friday 12 2016.
This is the kind of weather the boathave to deal with in the Indian Ocean, south of Africa and Australia. The storms in the Roaring Forties is very evident.
The spars and fittings has become to heavy.
Back to square one.
The first set was made of wood and the fittings metall. It became far to heavy.
Now one mast is gone. Left is two mast 2 yards and 2 booms made of carbon. The metall fittings is replaced by knots.
Photos below illustrates.
The weight of the fitting is 0,215 kilos. 4 on each sail 2 sails = 1,72 kilos
Instead I now use knots.
A wooden test piece is here tested to 150 kilos. At 250 kilos the wooden spar broke.
Turks head knots akt as stoppers. Dynema rope twice around the spar secured with a buntline hitch. The sail will be atached by a backturn and a half hitch.
This system is only a fraction of the previus weight.
The wooden spars is now replaced by carbon spars.
The weight of the rigging is reduced to one third.
Progress have also been made on the yuloh.
The new one got much better balance. The blade is now 18 cm wide instead of 12. It will move more water for higher efficiency.
Tomorrow I drive to G├Âteborg for the boat show and other things including a vacuumchamber to pack food.
To be continued…