Return-Path: <13brv3@bellsouth.net> Received: from imf19aec.mail.bellsouth.net ([205.152.59.67] verified) by logan.com (CommuniGate Pro SMTP 4.1) with ESMTP id 2516696 for flyrotary@lancaironline.net; Sun, 10 Aug 2003 19:33:47 -0400 Received: from rad ([68.212.0.134]) by imf19aec.mail.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20030810233347.QNTI22300.imf19aec.mail.bellsouth.net@rad> for ; Sun, 10 Aug 2003 19:33:47 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Cooling fans Date: Sun, 10 Aug 2003 18:33:47 -0500 Message-ID: <000b01c35f97$d915a280$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000C_01C35F6D.F03F9A80" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_000C_01C35F6D.F03F9A80 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit After you look at that for a while, you will notice that you can use a single pole double throw switch, and switch only the powered side and let aircraft ground do the other side. I knew there was going to be a problem with the fan free-wheeling, so I had a SPDT switch wired as you described. My fan was probably the worst case, since it was 16", and was on the outside of the radiator, so the prop blast hit it directly. Still kinda surprised it blew the fuse. I've used aftermarket fans on cars before, and never had a problem like this. If I didn't have better things to do, I'd investigate this further. Cheers, Rusty (the untuned) ------=_NextPart_000_000C_01C35F6D.F03F9A80 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

After you look at that for a while, you will notice = that you can=20 use a single pole double throw switch, and switch only the powered side = and let=20 aircraft ground do the other side.

 
I knew = there was going=20 to be a problem with the fan free-wheeling, so I had a SPDT switch wired = as you=20 described.  My fan was probably the worst case, since it was 16", = and was=20 on the outside of the radiator, so the prop blast hit it directly.  = Still=20 kinda surprised it blew the fuse.  I've used aftermarket fans on = cars=20 before, and never had a problem like this.  If I didn't have better = things=20 to do, I'd investigate this further. 
 
Cheers,
Rusty = (the=20 untuned)



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