d.
Verify that the propeller is full of fluid grease (that must pour) and seep to
the outside of the propeller.
e.
Make sure that the propeller is protected from galvanic corrosion by applying
the proper zinc anodes on the propeller and drive shaft.
f.
Be sure that the values of the forward and backwards motion pitch set on the
propeller you received correspond to those optimal for your boat. If you have
any doubts please refer to the sections 5 and 6 concerning the calculation
and the adjustment of the propeller pitch.
5.
HOW TO DETERMINE THE OPTIMAL FORWARD MOTION PITCH
AND / OR THE OPTIMAL BACKWARDS MOTION PITCH
OF THE PROPELLER
The diameter and pitch must be calculated as if MAX PROP
®
EASY/WHISPER
was a common fixed-pitch propeller. With respect to traditional propellers,
MAX PROP
®
EASY/WHISPER allows the users to adjust the pitch according to
their needs. This great advantage allows the pitch to be optimized if during
navigation the performance is not completely satisfactory or in case of changed
characteristics of the propulsion system. If the engine does not reach the
operating number of revolutions, then the blade angle α must be decreased;
if, on the contrary, the operating number of revolutions is exceeded, then the
angle α must be increased. The fig. 4 below shows the theoretical pitches in
millimeters corresponding to the different blade’s angles for a number of
propeller diameters.
With good approximation we can consider that , at the same RPM, the boat
speed varies directly with the variation of angle α. Or that, at the same boat
speed, the RPM of the engine varies inversely with the variation of the angle α.
For example if the angle α is increased by 10%, at the same RPM, the boat speed
will increase by 10% and vice versa . Or, if the angle α is increased by 10%, at the
same boat speed, the RPM of the engine will decrease by 10% and vice versa.
