Chris Cosman wrote:

     > 30" is about right if your joining the rotors together, including the cast
     > iron portion. Less than half the length if it's independent runner. I've done
     > alot of work in this area, 4900rpm. Skip

Probably better to make it adjustable +/- 5 inches.

--
Chris
microcosman.com

Good idea as 30.0 inches might give you too much torque on takeoff
and sacrifice some high end power at 6300 RPM.
I think Ed or Chuck are already seeing something like this as I recall.
Something like going past prop stall on take off.

With a fixed pitch prop I am not sure if you can take advantage
of the longer runners at 4900 RPM.

Paul Lamar

I do not think too much power at static and take off
is a real problem - if you have enogh power to turn
the prop faster you will get more thrust, stalled
section or not - Vance

Ed and Chuck I think were seeing some inexplicable RPM numbers
changing in strange ways during takeoff. Could be aliens from outer space.

Paul Lamar

Increasing engine load as you gain forward speed,
processing more air weight flow, and progressively
unstalling portions of the prop, are not really unusual
with planes using steep pitched fixed props. This
does not mean that you had too much power at static.
This phenomena is likely to become more common if
you go to the steeper gear reductions that you
are proposing, since it will drive you to steeper
props. Vance
--

I guess I don't notice it with my CS prop on the 182.

And more power with faster airplanes. I think variable
pitch props will not only improve takeoff and climb but
will give us more MPG.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.
ACRE NL web site.
http://home.earthlink.net/~rotaryeng/            http://www.linux.org