X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mx2.netapp.com ([216.240.18.37] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTPS id 4630107 for flyrotary@lancaironline.net; Sun, 05 Dec 2010 13:35:35 -0500 Received-SPF: softfail receiver=logan.com; client-ip=216.240.18.37; envelope-from=echristley@nc.rr.com X-IronPort-AV: E=Sophos;i="4.59,302,1288594800"; d="scan'208";a="491299566" Received: from smtp1.corp.netapp.com ([10.57.156.124]) by mx2-out.netapp.com with ESMTP; 05 Dec 2010 10:34:58 -0800 Received: from [10.30.20.98] (prichard2-lxp.hq.netapp.com [10.30.20.98] (may be forged)) by smtp1.corp.netapp.com (8.13.1/8.13.1/NTAP-1.6) with ESMTP id oB5IYvUn010977 for ; Sun, 5 Dec 2010 10:34:58 -0800 (PST) Message-ID: <4CFBDB52.1070904@nc.rr.com> Date: Sun, 05 Dec 2010 13:34:58 -0500 From: Ernest Christley Reply-To: echristley@nc.rr.com User-Agent: Thunderbird 2.0.0.24 (X11/20100623) MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Revmaster PM Alternator / Ignition System References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Finn Lassen wrote: > I do wonder what the weight of the stator ring and magnets are. > The stator is probably a pound. Two at most. I know mine doesn't weigh much. My rotor uses iron magnets in a 0.100" thick housing. It is fairly heavy. Using rare earth not only makes for lighter magnets, but also a lighter housing that doesn't have to contain as much centripetal force. If the rotor housing is made of aluminum, I bet the whole affair is under 5lbs. > A coupe of other factors: I don't like the high-power resistors. I > would seem that one could make an efficient switching power regulator > that would not waste power in resistors. Also, the electronics being > in the housing may be an issue. I assume the housing will be the same > temperature as the engine and thus it may be more difficult to get rid > of the heat from the electronics (if using the housing as a heat sink). I don't like the whole electronics package. Power resistors may be used because of the heat issues you mention, so I think that can be forgiven. What I can't see past is the circuit board that looks like a cheap epoxy RadioShack prototype board, with wires sticking out like a Rastafarian hairdo, the complete ignorance of proper strain relief, and ridiculous lack of sane wire routing. But, that's just me.