X-Virus-Scanned: clean according to Sophos on Logan.com X-PolluStop-Diagnostic: (direct reply)\eX-PolluStop-Score: 0.00\eX-PolluStop: Scanned with Niversoft PolluStop 2.1 RC1, http://www.niversoft.com/pollustop Return-Path: Received: from [207.189.223.49] (HELO email3.peakpeak.com) by logan.com (CommuniGate Pro SMTP 4.3c4) with ESMTPS id 867255 for flyrotary@lancaironline.net; Wed, 13 Apr 2005 02:37:57 -0400 Received-SPF: none receiver=logan.com; client-ip=207.189.223.49; envelope-from=billdube@killacycle.com Received: (qmail 1873 invoked by uid 513); 13 Apr 2005 07:21:52 -0000 Received: from 207.189.221.48 by email3 (envelope-from , uid 504) with qmail-scanner-1.23 (clamscan: 0.75.1. Clear:RC:1(207.189.221.48):. Processed in 0.5458 secs); 13 Apr 2005 07:21:52 -0000 Received: from 48-221-189-207.dyn.peakpeak.com (HELO tigger.killacycle.com) ([207.189.221.48]) (envelope-sender ) by email3.peakpeak.com (qmail-ldap-1.03) with SMTP for ; 13 Apr 2005 07:21:51 -0000 Message-Id: <4.3.1.0.20050413002428.041dfd60@mail.chisp.net> X-Sender: billdube@mail.chisp.net X-Mailer: QUALCOMM Windows Eudora Version 4.3.1 Date: Wed, 13 Apr 2005 00:34:51 -0600 To: "Rotary motors in aircraft" From: "BillDube@killacycle.com" Subject: Whyn is there a balance weight? (was: Rx-8 Rotors....) In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed >Ed Don't forget lighter rotors would require different balance weights. This is going to be a silly question to the experts, but I can't help but ask it: I haven't been able to understand why the balance weight is even needed. I don't doubt that it is needed, but I don't understand why. I look at the eccentric shaft, and it is symmetric. The rotors are 180 degrees out in relation to each other. The rotors spin 1/3 as fast as the eccentric shaft, to which the balance weight is attached. How would the quickly-turning balance weight do anything in opposition to the rotors? What, exactly, does the balance weight counter balance?