Prop Selection

[Tom Simes]

On Mon, 18 Oct 2004 11:56:08 -0500
"Nat Penton" <natpenton at centurytel.net> wrote:

> I tried the formula and was not happy with the results. Will do more
> research and report.                     Nat
>   ----- Original Message ----- 
>   From: Nat Penton 
>   To: discussion at nsrca.org 
>   Sent: Sunday, October 17, 2004 10:59 PM
>   Subject: Prop Selection
> 
> 
>   Courtesy of Mike Nauman's "Pattern Plane Design"
> 
>   For equivalent props the following would be a constant:
>             no of blades x  pitch (squared) x Diameter (cubed)
> 
>   No of blades defined as 2, 3 or 4

I only fly two bladed props, but at least for the .40 - .75 two stroke
engines I fly I find the formula of (2 x dia) + pitch to be a good rule
of thumb for moving up and down props.

For example, on my .46 AX I like a 10.5 x 6 APC which works out to a
load value (for lack of a better term) of 27.  I've found that as long
as I keep the load numbers +/- 2 points for that engine I am happy with
the performance.

I'm pretty sure that I got the formula off this list but I don't know
who to attribute it to.

-- 
Tom

_____________________________________________________________________


       |  ,  |                  Tom Simes - AMA 230068
---------(@)---------           nsrca at shinymetalass.com
        --|-- 
          '
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