KR> Fw: Re: Propellers

2014-05-12 Thread tommy waymack via KRnet
r Props): The efficiency of a propeller > is reduced as the tip speed approaches the speed of sound. Beyond 80% of > the speed of sound, further increases in RPM has little effect on thrust. > Thus, it is important to keep tip speeds below 75%-80% of Mach. > > > > > > Bottom li

KR> Fw: Re: Propellers

2014-05-10 Thread Jeff Scott via KRnet
age - > From: JL > Sent: 05/09/14 11:12 PM > To: Jeff Scott, KRnet > Subject: Re: KR> Fw: Re: Propellers > > Jeff, > > Since I don't disagree with almost everything you posted, I suspect we are > commenting about the same elephant, but from different ends ; ) >

KR> Fw: Re: Propellers

2014-05-10 Thread Jeff Scott via KRnet
itial take off and climb. -Jeff Scott Los Alamos, NM <http://jeffsplanes.com> > - Original Message - > From: schmleff . via KRnet > Sent: 05/09/14 11:39 AM > To: tommy waymack, KRnet > Subject: Re: KR> Fw: Re: Propellers > > Not to start an argument, b

KR> Fw: Re: Propellers

2014-05-10 Thread JL via KRnet
s a compromise. Within reasonable limits a lower pitch, longer prop > will provide more thrust for initial take off and climb. > > -Jeff Scott > Los Alamos, NM > <http://jeffsplanes.com> > >> - Original Message - >> From: schmleff . via KRnet >> Sent:

KR> Fw: Re: Propellers

2014-05-09 Thread schmleff . via KRnet
Not to start an argument, but I have to disagree ; ) How a prop works on a particular airplane is based on the amount of air moved (past the cowl, not smashing into it) and the velocity of that air. I have never been able to find a real reference to the ?large diameter prop=better climb? theory

KR> Fw: Re: Propellers

2014-05-09 Thread tommy waymack via KRnet
The longer the prop the better climb performance of the aircraft.The magic of prop science never seems clear.That maybe why we call it EXPERIMENTAL.And yes I do learn a lot from it.Tommy W. On Thu, May 8, 2014 at 12:12 PM, Randall Smith via KRnet < krnet at list.krnet.org> wrote: > Every prop I

KR> Fw: Re: Propellers

2014-05-08 Thread joe.kr2s.buil...@juno.com via KRnet
Doran Jaffas wrote: > Just curious if anyone has run a 50 inch propeller. I have a 52 by 47 and > am thinking of trimming it down to 50 inches the add a couple of hundred > rpm. My experience with a 2" difference in prop diameter and no other change is only in the neighborhood of 50 to 70 rpm

KR> Fw: Re: Propellers

2014-05-08 Thread Randall Smith via KRnet
Every prop I have cut had given me 100 rpm per in up to 3". Sent from my iPhone > On May 8, 2014, at 11:44 AM, "joe.kr2s.builder at juno.com via KRnet" at list.krnet.org> wrote: > > Doran Jaffas wrote: >> Just curious if anyone has run a 50 inch propeller. I have a 52 by 47 and >> am thinking