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Old 06-12-2024, 17:20   #16
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Re: Is it left or right propeller ?

As viewed from the aft position [towards the fore].

Left-hand propellers rotate counterclockwise on the shaft, while right-hand propellers rotate clockwise on the shaft.

Similar to screwdriver handedness.

A right-hand propeller rotates like a right-hand threaded fastener will screw into a hole.


Three methods of determining handedness of a screw propeller:


First Method – Blade Angle on Hub

Identify the parts of your impeller – there will be 3 blades and a hub

1. Place blade flat on table
2. Observe the hub from a side angle to determine which way the blades are running
3. If blade angle runs from top left to bottom right it is a left-hand propeller
4. If blade angle runs from bottom left to top right it is a right-hand propeller


Second Method – Palm Demonstration

1. Place the hub of the propeller in the palm of your hand
2. Relax your thumb
3. If your thumb lies comfortably on the blade in your left hand it is a left-hand propeller. You can do the same with your right-hand. If your thumb lies comfortably on the blade in your right hand it is a right hand propeller.


Third Method – Flow of Material

1. With a clockwise rotating shaft a left-hand propeller will direct your material flow downward. A right-hand propeller will direct your material flow upward.
2. A counterclockwise rotating shaft will produce the opposite flow results.


Also very similar to whether one's Mickey Mouse hat's ears are lefty or righty.

Bon voyages.

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Old 13-12-2024, 12:58   #17
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Re: Is it left or right propeller ?

Quote:
Originally Posted by rls8r View Post
Figure out which way the shaft rotates when you have your transmission in 'forward.'

Open your right hand so the four fingers are together and your thumb is extended to the side (like your forefinger and your thumb are making a flattened letter 'j').

Wrap the fingers of your right hand around the shaft with the fingers in the direction that the shaft rotates when in 'forward.'

If the thumb is pointing forward and the prop is turning so it will push water to the rear - then the prop is 'right-handed.' Otherwise, it is 'left-handed.'

Brilliant!!! Much easier to picture then imagining prop is a screw and which way you would have to turn it to screw it into the water.
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Old 14-12-2024, 11:10   #18
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Re: Is it left or right propeller ?

Quote:
Originally Posted by CrispyCringle View Post
Ive never understood why a rotating object is described as "right" or "left". It would be the same as describing it as an upward or downward prop. It should be something everyone can understand without having to come up with hand exercises to figure it out, like clockwise or anti-clockwise. Im not criticising the hand techniques. Its just dumb that thats what we have to do.
It is simple. one does not buy bolts or screws that are 'clockwise or anti-clockwise. just like tigtening a screw or a bolt. (righty tighty lefty loosey). Somewhere in the history of man, things that turned in a clockwise direction were called right handed. Things that turn counter clockwise were called left handed. it is a standard. if you are behind the boat, looking at the prop in forward gear and it is turning clockwise it is called right handed..

You do not have to use a hand exercise, you just look at the blades, The leading edge of the prop is the blade edge nearest the front of the boat . the leading edge bites into the water to pull the boat in that direction. So if you turn the prop in the direction of the leading edge, that direction is forward and if it is clockwise it is a right hand prop.

M
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Old 14-12-2024, 15:40   #19
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Re: Is it left or right propeller ?

Quote:
Originally Posted by CrispyCringle View Post
Ive never understood why a rotating object is described as "right" or "left". It would be the same as describing it as an upward or downward prop. It should be something everyone can understand without having to come up with hand exercises to figure it out, like clockwise or anti-clockwise. Im not criticising the hand techniques. Its just dumb that thats what we have to do.
Just to make you crazy...springs like garage door springs for example, can be right handed or left handed. You need to know when ordering new ones. The right hand rules, so to speak.
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