This has been the most difficult part of the design of the boat. Being a proa, she has to sail in both directions, so she has to 'kick up' her rudder/daggerboards in both directions as they stick out below the draft by 1 1/2 metres when fully extended, and hitting a sandbank, coral reef, whale, log or semi-submerged container need to be considered. None of the other Harryproas has thus far completely sorted this problem, because while some of them kick up, it also takes them a long time to be reset to regain steering ability.
As an aside, Harryproas have a tendency to 'luff up' unless the daggerboard/rudder is way back at the stern ensuring the CLR (centre of lateral resistance) is sufficiently far back and behind the CofE (centre of effort). This makes them difficult to access in a kick up situation.
Another ingenious idea from Peter of Etamax (petere@etamax.com.au) is a way to adjust the pintle angle so that the rudder remains balanced in both directions. After a shunt the top of the pintle will move to the forward position of the new direction. The forward limit can be adjusted with screws so that the best rudder balance can be found.
This pic is of the wound carbon fibre pintles and detent blocks. The pintles look extremely strong, and need to be considering the load they will take, with daggerboard/rudder fully down. They can be raised vertically or rotated into different detents. This is to allow for more balancing of the CLR at different sailing angles.
Finally a pic of one of the bearing (drum) outer sleeves, yet to be finely machined. All should be ready to send to me from Oz next month.
The importance of getting this steering right and the strength required convinced me to have them professionally made, as were the Rudder/Daggerboards themselves.
As an aside, Harryproas have a tendency to 'luff up' unless the daggerboard/rudder is way back at the stern ensuring the CLR (centre of lateral resistance) is sufficiently far back and behind the CofE (centre of effort). This makes them difficult to access in a kick up situation.
The idea is that the spring holds a pin in one of the detents. By pulling up on the handle the drum can be rotated so the pin can slip into another detent at 20 deg, 40 deg, (or 80 deg if wanted completely out of the water). The spring strength can also be adjusted by slotting it higher or lower so that the pin will jump out of a detent with whatever required force on the rudder. Complex but very versatile, which is why it is taking a while to manufacture.....
The importance of getting this steering right and the strength required convinced me to have them professionally made, as were the Rudder/Daggerboards themselves.
