Feathering propeller parts and operation

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Part

Number

A

Inner hub / reverse cam 1inch

1192-1

 

Inner hub / reverse cam 1 1/8

1192-1 1/8

 

Inner hub / reverse cam 1 1/4

1192-1 1/4

B

Back lash shim

1258

C

Drag screw

1257

D

Outer hub / spindle

1193

E

Locking plate

1199

F

Locking plate screw

 

G

Thrust washer front

1202

H

Thrust ring

1203

 

Blade 14

 

 

Blade 15

1194

 

Blade 16

1195

I

Blade 17

1196

J

Pitch screw

1197

 

Elastic stop nut -10

 

 

Elastic stop nut 7/8-9

 

 

 

 

 

Pitch plate

 

 

 

 

Theory of operation

       While sailing, the blades of the feathering propeller weather vane to reduce drag. Under power forward the center of water pressure on the blades is aft of the point of rotation (the spindles) causing the blades to rotate to the forward stop pin. An adjustable set screw in the blades controls the exact pitch. In reverse, the drive torque causes the reverse cam to rotate the blades to the reverse position so the prop acts like a fixed prop in reverse.

            Because the propeller is designed to optimize motoring performance as will as feather, there is considerable twist and lift built into the blades. While sailing, this can cause the outer hub/blade assembly to rotate around the reversing cam, forcing the blades into the reverse position. To prevent this, there is a drag screw which prevents this rotation. That same twist and lift from the blades will cause the prop and shaft to rotate slowly while under sail, even when feathered, if the engine is left in neutral. To prevent this (if desired) put the engine in gear or use a shaft lock.

 

To insure proper feathering, power in forward immediately prior to shutting the engine down. If you shut down after being in reverse, the blades will stay in the reverse drive position and will not feather. Idling in neutral will not change the blade position.

OPERATION

       Forward Engage the forward gear with the motor idled to below 1000 rpm. Advance the throttle as desired after the gear is engaged

 

            REVERSE.  Idle the motor to less than 1000 rpm. Engage the reverse gear and advance the throttle as desired.

 

       FEATHERING.  The prop will feather only after having been run in forward. You must engage the gear shift in forward prior to shutting down the engine although it can be left in neutral before shutting down. After shutting down the motor can be put in gear (normally reverse) to lock the shaft or use a shaft lock if desired. See engine manual.

 

Please note: many marine transmission manufacturers void their warranty if the engine has been engages at more than 1000 RPMs. Please observe this limit to preserve the integrity of the drive train and propeller reverse stop.

 
 
 
 

Clearances

            All propellers should have at least 15% of their diameter in clearance between the blade tips and the hull anything less will reduce the propeller’s efficiency and may result in excessive vibration, noise and “walking” in reverse. Fore and aft clearances should be at least as much as tip clearances.

 

we have a diagram that shown the proper clearence and how to measure the clearence  see Feathering propeller clearence

2BLADELETTERS.jpg

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Powering position

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Feathered position

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Performance Propellers


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Homer, NY 13077                             Fax 607-749-4604

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