KiwiProps North America
The Kiwi Feather Prop ...
Unique Composite feathering propeller for yachts
HOW IT WORKS
When sailing, each blade is free to weather vane into the unique and constantly varying water flow. The near neutral buoyancy of the Zytel allows an immediate response to any change in direction. With each blade correctly feathered and the shaft free to rotate, the absence of any autorotation is proof of the fully feathered status of the unit.
When motoring ahead, as the propeller starts to rotate, the blades weather vane around to the pitch stop, where they are then held in the preset pitch position to generate forward thrust. Upon disengaging the motor, the unit automatically reverts to the sailing status described above.
When reverse is engaged, the blade carrying assembly feels the torque from the water. This winds up the internal spring, thus allowing the small rollers on the mushroom end to force and lock each blade back to the ahead position (see graphic below). The whole unit then starts to rotate in reverse and effectively operates as a fixed three bladed unit, thus delivering optimal reversing performance. At the end of the reversing cycle, the spring returns the unit to the normal sailing status.
These units have now been tested and developed over many years in real life situations in Auckland, home of the America’s Cup, where they are fast becoming the propeller of choice. They are now available to yacht owners everywhere with the direct customer access that the internet and international air courier facilities provide.
The Kiwi Feather Prop brings a truly innovative set of values to yacht owners and designers striving to get the very best all round motoring, reversing, and sailing performance for their vessel.
Aligns feathered blades with water flow, not the shaft.
Patented Feature: Blades free to trail like weather vanes.
Feathered propeller does not auto-rotate. Eliminates shaft locks.
Full pitch immediately in reverse. Compensates for the higher reduction ratios gearboxes utilize in reverse to provide maximum maneuverability.
Robust, low stress design without highly stressed gears.
Fail safe design features built around composite blades and nose cone which minimize corrosion and lubrication problems.
Hi-tech Zytel blades give strength and light weight with low inertia and no shock loading. Easy to replace and lubricate but well locked in against blade loss.
Near neutral buoyancy means blades are responsive to the smallest changes in water flow thus always minimizing drag when sailing.
Blades pivot over cast stub shafts, not cantilevered from washer type bearings with very high stress loading.
Eliminating the gearing allows the economical production of 3-bladed units which are more efficient and smoother running.
Easy pitch adjustment with self locking set screws in each blade allows optimal performance adjustment and eliminates inventory.
Common boss accommodates all standard shafts and Saildrives.
Rather than try to post lots of past, current and future technical information, we prefer to send you to the New Zealand factory site and Pick John Blundell's website and brain! www.kiwiprops.co.nz