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| Outboard
Questions • Sterndrive
Questions |
Q:
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What
are true pitch, variable pitch and controllable pitch propellers?
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A: |
A true pitch propeller measures constant pitch at any radius
. . . a section of a true helical surface. A propeller whose pitch
varies radially, that is, is not constant but increases from the hub
to the tip, is a variable pitch propeller. Variable pitch propellers
are used on high speed crafts and reduce cavitation which might result
at such speeds. Many larger boats use variable pitch propellers to
compensate for wake or varying inflow velocities which result from
the depth of the immersed hull. With a controllable pitch propeller,
the pitch angle of the blades can be mechanically adjusted when the
boat is underway. |
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