Bill,
I have the SR3000/2W 2-blade with narrow ends and wide root with a lot of
twist. It is now running very smoothly, although I had a lot of problems
initially with vibration, which was due to carbs not well balanced. A
3-blade seems to cancel out a lot of uneven combustion. The instrumentation
was hopeless and I am now installing the Mark Burton controller.
Advantages are: less weight, cheaper, better visibility when feathered for
gliding, less drag, and it comes to you fully assembled ready to bolt on.
There are supposed to be other advantages like high altitude performance,
but have not done any serious testing yet.
Apparently Kim Prout has the best performing prop ? With a weight of 13 1/2
pounds that is half the weight of most cs props.
If you are building a mono, then my prop would be too long for you,
Karl
>From: Graham Singleton <grahamsingleton@btinternet.com>
>Reply-To: europa-list@matronics.com
>To: europa-list@matronics.com
>Subject: Re: Europa-List: Re: Woodcomp propeller controls
>Date: Thu, 07 Jun 2007 00:56:32 +0100
>
><grahamsingleton@btinternet.com>
>
>Bill
>A three blade prop will balance both mass and yaw forces. A two blade
>won't. There will always be a yawing vibration with a 2 blade whenever
>there is significant angle of attack. (Downgoing blade sees a different AoA
>to Upgoing one)
>End result is that in general 3 bladers are smoother than 2 blades.
>imho electric is cheaoer than hydraulic but not as fast so electric is no
>good for aerobatics.
>Graham
>Bill & Sue wrote:
>><Billandsue@billbell.co.uk>
>
>>In general terms, could anyone explain the benefits of a three-blade prop
>>over a two blade, and whether these outweigh the weight penalty?
>>And, while Im seeking enlightenment, how do the benefits of electric CS
>>props compare with the hydraulic variety?
>>
>>Bill
>
>
_________________________________________________________________
The next generation of Hotmail is here! http://www.newhotmail.co.uk
|