X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [216.52.245.18] (HELO ispwest-email1.mdeinc.com) by logan.com (CommuniGate Pro SMTP 5.0.5) with ESMTP id 903276 for flyrotary@lancaironline.net; Tue, 27 Dec 2005 18:47:55 -0500 Received-SPF: none receiver=logan.com; client-ip=216.52.245.18; envelope-from=wschertz@ispwest.com Received: from 7n7z201 (4Cust3.VR1.CHI6.broadband.uu.net [63.13.186.3]) by ispwest-email1.mdeinc.com (Vircom SMTPRS 4.2.425.16) with SMTP id for ; Tue, 27 Dec 2005 15:47:01 -0800 X-Modus-ReverseDNS: OK X-Modus-BlackList: 63.13.186.3=OK;wschertz@ispwest.com=OK X-Modus-RBL: 63.13.186.3=OK X-Modus-Trusted: 63.13.186.3=NO Message-ID: <019e01c60b40$1c8bbc10$0400000a@7n7z201> From: "William" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Alternate alternators Date: Tue, 27 Dec 2005 17:48:56 -0600 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 I don't understand something 0.577HP = 19041 #-ft/min, 19041 #-ft/min / 400 R/min = 47 ft-# Where did the 63.024 factor come from? Bill Schertz KIS Cruiser # 4045 ----- Original Message ----- From: "Ernest Christley" To: "Rotary motors in aircraft" Sent: Tuesday, December 27, 2005 10:32 AM Subject: [FlyRotary] Alternate alternators > One of the things Richard and I discussed yesterday was going with the > RX-8 style of pickup and using the distributor shaft to drive an > alternate power source. He rightly noted that the gears probably aren't > rated to be very strongs, since all they do is drive the distributor and > oil pumps. The questions are 1)How much load would a generator add? > and 2) How much load can the gears take? > > I don't have anything for the second question, but I got some numbers > for the first part using: > http://www.aeroelectric.com/articles/alternators/UA/Alternators_3.html > > Assuming a 20A load at an 800RPM idle as the highest torque a 65% > efficient generator would be applying: > > (14V x 20A)/.65 = 431W needed to drive the generator. 431/746 yields > .577HP. > > (.577HP x 63.024) / 400RPM = .091 in-lb of torque on the gear. > > .091in-lb? I keep thinking that I missed something or miscalculated. > Couldn't even cheap nylon gears could handle this sort of load? Is > there any reason not to trust the distributor drive gears to be able to > drive an alternate power source? > > -- > ,|"|"|, | > ----===<{{(oQo)}}>===---- Dyke Delta | > o| d |o www.ernest.isa-geek.org | > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/