[Public-List] Prop Survey

[Don Campbell]

  Here is a free ware programme for you to play with. You will find that 
you cannot apply more than about 16 HP to an Alberg prop to get 
hullbspeed regardless of the motor. It works on excel and the pages at 
the bottom are the entry options. I have a 13-8 2 blade and it works 
just fine. You will also find that 7 is the normal pitch and that if you 
go lower to a 6 you will have more power at slow speeds and an 8 will 
give you more power at high speeds. Because I rarely need power at slow 
speeds, I chose an 8 for the power at high speeds- less slippage and 
there is about 50 -55% slippage built in to every prop. That is a waste 
as far as I am concerned. 13 is the max diameter that you can get into 
the space in the rudder. You will note the rules of thumb on the 
relationship between pitch and diameter and RPMs for the motor. Match 
those to the torque and HP curves for your motor.
Don #528

On 8/12/2012 4:05 PM, Jeffrey wrote:
> I'm curious about what propellers others are using in their A30's?
>
> My boat came with a large three bladed prop, I can't remember the size
> but it was tight in the aperture.
> https://picasaweb.google.com/lh/photo/Fpj8A9TYOoJ72WipyH_XMNMTjNZETYmyPJy0liipFm0?feat=directlink
>
>
> Each blade was big! It really moved the boat well. Unfortunately that
> old prop was less bronze and more copper so we changed it when I
> replaced the shaft. After hearing such good things about the Campbell
> Sailer prop, I ordered one after speaking with Norm at West by West
> Enterprises. http://www.westbynorth.com/CampbellSailer.aspx. Norm was
> great to work with, and after discussing back and forth I ordered the
> 12" diameter x 8" pitch three bladed Campbell Sailor.  My first
> reaction when I received it was that it was TINY compared to the old
> prop!  I think Norm got the size right, the prop was able to push the
> boat to hull speed just about at the max of my motor. However, after
> three seasons with this, I'm contemplating a new prop.  What I dislike
> about the Campbell Sailer is that it is very sensitive to seaweed.
> Even a small bit of weed, or grass and we're lucky to hit 2 knots.
> With this prop, removing seaweed is almost a daily chore if we are
> traveling very far.
> https://picasaweb.google.com/lh/photo/botBsyVFuOPFFBQSC2_OhdMTjNZETYmyPJy0liipFm0?feat=directlink
>
> So, if you know what size prop you have and are happy with it please speak up!
>
> Jeff Fongemie
> #116 Seagrass
>
> http://picasaweb.google.com/fongemie
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