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 web81002.mail.yahoo.com ([206.190.37.147] verified) by logan.com (CommuniGate Pro SMTP 4.3c4) with SMTP id 864750 for flyrotary@lancaironline.net; Mon, 11 Apr 2005 09:25:08 -0400 Received-SPF: none receiver=logan.com; client-ip=206.190.37.147; envelope-from=deltaflyer@prodigy.net Message-ID: <20050411132424.18641.qmail@web81002.mail.yahoo.com> Received: from [199.231.49.128] by web81002.mail.yahoo.com via HTTP; Mon, 11 Apr 2005 06:24:24 PDT Date: Mon, 11 Apr 2005 06:24:24 -0700 (PDT) From: James Maher Subject: Re: [FlyRotary] Re: RV10 Cowl To: Rotary motors in aircraft In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-434326874-1113225864=:17067" --0-434326874-1113225864=:17067 Content-Type: text/plain; charset=us-ascii Bill, I'm not a mechanical engineer nor do I play one on TV but I believe that the standard for engine mounts are designed to withstand a minimum of 9 g's due to the high vibration environment. If the aircraft was intended to do aerobatics them I would guess that to be even higher. When I asked the designer of my aircraft to designate the tube sizes for the mount that I designed he used 9 g's for his calculations. Jim "BillDube@killacycle.com" wrote: Since I'm playing around with making my own engine mount, I looked carefully at the engine mount in your CAD drawing. I have a couple of questions. 1) Did you do a finite element analysis on the mount you have drawn? 2) I don't see anything aside from the one C channel supporting the engine. I don't understand how this would be able to react the loads. I'm in the middle of modeling the standard RV-7 Lycoming Dynafocal mount so I can do FEA to determine what g loads it will withstand and what it's vibrational modes are. When I finish "reverse engineering" the standard mount, I'll design my own RX-8 mount to withstand the same loads. Any clue what sort of loads one should expect the engine mount to withstand? Bill Dube http://www.killacycle.com/Lights.htm >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html --0-434326874-1113225864=:17067 Content-Type: text/html; charset=us-ascii

Bill,

I'm not a mechanical engineer nor do I play one on TV but I believe that the standard for engine mounts are designed to withstand a minimum of 9 g's due to the high vibration environment. If the aircraft was intended to do aerobatics them I would guess that to be even higher.

When I asked the designer of my aircraft to designate the tube sizes for the mount that I designed he used 9 g's for his calculations.

Jim

"BillDube@killacycle.com" <billdube@killacycle.com> wrote:

Since I'm playing around with making my own engine mount, I looked
carefully at the engine mount in your CAD drawing. I have a couple of
questions.

1) Did you do a finite element analysis on the mount you have drawn?

2) I don't see anything aside from the one C channel supporting the engine.
I don't understand how this would be able to react the loads.

I'm in the middle of modeling the standard RV-7 Lycoming Dynafocal mount
so I can do FEA to determine what g loads it will withstand and what it's
vibrational modes are. When I finish "reverse engineering" the standard
mount, I'll design my own RX-8 mount to withstand the same loads.

Any clue what sort of loads one should expect the engine mount to withstand?

Bill Dube
http://www.killacycle.com/Lights.htm

>> Homepage: http://www.flyrotary.com/
>> Archive: http://lancaironline.net/lists/flyrotary/List.html

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