Sheeting angles

[Midniteblue]

Typically, the main boom angle on the beat is about 5 degrees, while for the jib it is around 15 degrees. The aerodynamic space between main and jib to reduce loss of lift is the Slot.
In the process of opening the sails to a reach, let say 45 degrees, would you prefer to maintain the Slot constant, or to have the main boom “catch up" to the jib to have similar sheeting angles, that means the main moving out about 40 degrees while the jib only moves out about 30 degrees.

Thank you

[Rick West]

Val,
I think everyone is doing this and has been for some time.

First the relationship for the sail plan is fixed with the exception of the jib trim during set up.

Secondly, the sheeting and then the jib trim are positioned to the conditions we are sailing. Often this changes about every 10 seconds.

Pre- tune set up begins at full sheet out. The main is about 80-85 degrees and the jib 90.
When sheeted in the main will be about 5 degrees of center and the jib set to the condition…the higher the wind the narrower and so on. Many have enough jib trim to set the neutral setting for the jib club to point just inside the chainplate. From here they will trim in on the beat to weather for higher winds and out for lighter air.

If the sheet out settings do not match the close haul setting you want then set close haul and program your full sheet out position above with the TX. Most this the other way around during pre-tune but I was making a point of what both should be.

From the neutral set up at the lake many will sail the heel of the boat. Meaning a steady heel sheeting in and out to maintain it relative to the changing wind velocity. This is to maintain the power you want and the speed you will get from it.

So, the pre-tune settings are what it will be. The main and the jib are moving, for all intent and purposes of this discussion, constantly in relation to the pre-tune setting. Changing ratios is not in my recommended tuning talk. There are too many variables that could, and will, change in the course of a heat.

Reference is Pre-Tuning in the Classis Rig section of http://www.ec12.info.


...94

[Carl]

The answer to the slot question can be what Lester Gilbert wrote.
See the web site below.


http://www.onemetre.net/Design/Slot/slot.htm

Carl