Rob

I took a couple of photos showing recent changes per attached.

The bows on the lw hull are now almost plumb with much finer entry at the deck. At 15kts the attached flow does not go higher than the deck now.

The helm has been relocated to the cockpit rather than off the side of the lw hull. This change makes steering considerably more intuitive. Each wheel is fitted with an orbital pump/motor operating in closed loop with the same size orbital pump/motor at the rudder gearbox. The 1:3.3 gearbox was retained to ensure the hydraulic pressure is low. The orbital pump/motor has the torque rating to be directly connected to the rudder but the operating pressure would be higher and that would increase bypass and require high pressure fittings and pipes. The whole system as installed required around AUD1100 in parts and materials.

Removing one of the gearboxes has made the steering much more direct and is now a tad heavy for the small diameter wheels. With hindsight it would have been better to use lower displacement pump/motor on the wheels to give about 1:6 overall rather than the previous 1:10.

We were contemplating providing automatic make-up in the hydraulic circuits using an air over oil accumulator with a feed in check valve and pressure relief to cater for thermal expansion and leakage in the circuits but the simple closed loops are working fine and orbital pump/motors are getting smoother with more use. Both circuits are leak free at this stage.

Rick