Mast Rake

[Steve1142]

Note to self and all concerned.
Even in very light winds don't pull the mast upright past the 6100 as i did yesterday for our New Years day Lemon hill race. as it makes it very hard to to tack and you find yourself going backwards to everyone's amusement.
Once i adjusted back, boat preformed very well and i worked my way up to 8th pace out of 20 for last.
Happy new Year Everyone
Steve 1142

[Pete1177]

Hi Steve,

As you found out, if you sail with the sail rig more forward (>6100mm) then the Centre of Effort (CE) of the sail plan is too far forward with respect to the Centre of Lateral Resistance (CLR) of the hull. This gives more lee helm (the boat will tend to steer off the wind). You will find the helm balance all wrong and the boat will have too much resistance (= slow) and it will be very hard to tack (i.e. get stuck in irons). In strong winds the boat will have a tendency to veer off and you'll be prey to accidental gybes.

Having a few degrees of weather helm is preferable as the tiller will feel more balanced and feel right. With neutral helm the tiller feels a bit vague. It also gives a faster boat as the rudder produces more lift and less leeway (if you keep the boat flat of course). The CE needs to be further forward than the CLR.

I set my rig that at 6100mm (fully upright) the rig tension is such that it's very difficult to pull on more.

Pete
SN1177
Class Secretary