<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><DIV>You probably already know this, but you would have to use a higher KV motor.</DIV>
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<DIV>Since electric motors can be wound many different ways, it is possible to run a much larger diameter prop at a lower rpm and have a more constant speed aircraft than would be possible with an I/C engine, unless of course you have a belt reduction drive like Dean Koger flew in the early 90s. (That thing was AWESOME!). That is one reason I can think of for the 13" prop restriction. Also, the 70s era planes would like kinda stupid with 10" gear struts. :-)</DIV>
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<DIV>Bob R.</DIV>
<DIV><BR><BR>--- On <B>Wed, 11/25/09, Jerry Combs <I><jcombs1947@att.net></I></B> wrote:<BR></DIV>
<BLOCKQUOTE style="BORDER-LEFT: rgb(16,16,255) 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><BR>From: Jerry Combs <jcombs1947@att.net><BR>Subject: Re: [NSRCA-discussion] Alabama Bound<BR>To: "General pattern discussion" <nsrca-discussion@lists.nsrca.org><BR>Date: Wednesday, November 25, 2009, 12:50 PM<BR><BR>
<DIV class=plainMail>I don't understand the 13" prop bit either. On my Axi 4130-20 on 6 cells a 13" prop gives me around 500 watts.<BR><BR>Jerry<BR><BR>Scott, What is the reason behind a 13 inch prop limit for electric? There<BR>isn't any limit on prop sizes for IC engines is there? A flyer with an IC<BR>engine searches for the best prop size to the particular plane and engine<BR>combo, it seems that electric flyers should have the same flexibility.<BR>Dave Burton <BR>_______________________________________________<BR>NSRCA-discussion mailing list<BR><A href="http://us.mc565.mail.yahoo.com/mc/compose?to=NSRCA-discussion@lists.nsrca.org" ymailto="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A><BR><A href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion" target=_blank>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</A><BR></DIV></BLOCKQUOTE></td></tr></table>