<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.6000.16414" name=GENERATOR></HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT size=2>prop noise.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>You can hear the difference in an APC prop if you sand the TE
to get rid of the knife edge. They are using the sharp TE and thin
airfoil.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Easy to confirm: Get a wattmeter and an electric
drive. Turn the APC prop appropriate for the motor and do a sound check...
then sand the TE (such as is commonly done by some people...) check sound
and power demanded by the motor again.</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=bob@toprudder.com href="mailto:bob@toprudder.com">Bob Richards</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, February 13, 2007 10:29
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Trailing
Edge</DIV>
<DIV><BR></DIV>
<DIV>Ok, why don't we chop off the trailing edge of our props?</DIV>
<DIV> </DIV>
<DIV>Bob R.</DIV>
<DIV><BR><BR><B><I>Nat Penton <<A
href="mailto:natpenton@centurytel.net">natpenton@centurytel.net</A>></I></B>
wrote:</DIV>
<BLOCKQUOTE class=replbq
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">
<META content="MSHTML 6.00.5730.11" name=GENERATOR>
<STYLE></STYLE>
<DIV><FONT face=Arial size=2>Dean</FONT></DIV>
<DIV><FONT face=Arial size=2>The old NACA must have done this research in
the distant past. I recall, in the 80s, Jim Bede extolling on the
virtues. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> The Princeton project, that would be fun,
especially as a student. Would have kept my attention
<G>.
Nat</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=d.pappas@kodeos.com href="mailto:d.pappas@kodeos.com">Dean
Pappas</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, February 13, 2007
10:03 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Trailing Edge</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff
size=2>Thanks Nat,</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff
size=2>I have a guy in the local club who corroborates Barnaby's
statement. Locally to NSRCA D1, back in the 80's he was known as
"forever in Sportsman George".</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff
size=2>He is recently retired from teaching at the Aero group at
Princeton U. and he still coaches the students involved in the weight
lifting contest.</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff
size=2>It was nice to have an excuse to go hunt him
down!</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff
size=2>later,</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff
size=2>Dean</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT
face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT
face="Times New Roman">Kodeos Communications</FONT> <BR><FONT
face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT
face="Times New Roman">South Plainfield, N.J. 07080</FONT>
<BR><FONT face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT
face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT
face="Times New Roman">d.pappas@kodeos.com</FONT> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org]<B>On Behalf Of </B>Nat
Penton<BR><B>Sent:</B> Tuesday, February 13, 2007 1:05 AM<BR><B>To:</B>
NSRCA Mailing List<BR><B>Subject:</B> [NSRCA-discussion] Trailing
Edge<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>Kitplanes, Dec
06 Wind
Tunnel by Barnaby Wainfan</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>" The airfoil with the chopped trailing
edge will produce slightly more lift at the same angle of attack than a
sharp trailing-edged airfoil. Because the wake is filled in the controll
is crisper and more effective and does not have to move as far to cause
a change in lift"</FONT></DIV></BLOCKQUOTE>
<DIV>
<HR>
<DIV></DIV>_______________________________________________<BR>NSRCA-discussion
mailing
list<BR>NSRCA-discussion@lists.nsrca.org<BR>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</DIV></BLOCKQUOTE>_______________________________________________<BR>NSRCA-discussion
mailing
list<BR>NSRCA-discussion@lists.nsrca.org<BR>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</BLOCKQUOTE><BR>
<P>
<HR>
<P></P>_______________________________________________<BR>NSRCA-discussion
mailing
list<BR>NSRCA-discussion@lists.nsrca.org<BR>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
<P>
<HR>
<P></P>No virus found in this incoming message.<BR>Checked by AVG Free
Edition.<BR>Version: 7.1.411 / Virus Database: 268.17.37/682 - Release Date:
2/12/2007<BR></BLOCKQUOTE></BODY></HTML>