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X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 50 [XX] (100%) RECEIVED: Received headers not consistent with Juno "FROM:" Return-Path: Received: from m04.lax.untd.com ([64.136.30.67] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with SMTP id 1873990 for flyrotary@lancaironline.net; Wed, 28 Feb 2007 10:56:48 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.136.30.67; envelope-from=lm4@juno.com Received: from m04.lax.untd.com (localhost [127.0.0.1]) by m04.lax.untd.com with SMTP id AABC8MKQ2A6NX4HS for (sender ); Wed, 28 Feb 2007 07:55:04 -0800 (PST) X-UNTD-OriginStamp: gV9QSHkwPVujJygYd5+ifRmzWpII858uwTBvxs+9Fek= Received: (from lm4@juno.com) by m04.lax.untd.com (jqueuemail) id MFN7ZQ5U; Wed, 28 Feb 2007 07:54:21 PST To: flyrotary@lancaironline.net Date: Wed, 28 Feb 2007 10:53:40 -0500 Subject: Re: [FlyRotary] engine mount 4130 vs 304 SS Message-ID: <20070228.105340.2168.1.lm4@juno.com> X-Mailer: Juno 5.0.49 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=--__JNP_000_10dc.02bc.3666 X-Juno-Line-Breaks: 8-6,7-19,21-23,28-29,32-34,35-32767 From: Larry Mac Donald X-ContentStamp: 9:4:3918415402 X-MAIL-INFO:0c6871ec2dbcf928790c5809157d1d3cf84d3c3d3981f81d8558f5fc78417c2811ad95ccf55835d15cddeddd48a19dd8dd X-UNTD-Peer-Info: 127.0.0.1|localhost|m04.lax.untd.com|lm4@juno.com This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ----__JNP_000_10dc.02bc.3666 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi Rusty, There is a very good reason for using 4130 and NOT stainless. Of course 4130 is always ready to get brittle but you can take care of that by rosebudding your welds. And 4130 has the best strenght to weight ratio of all metals. However,Stainless is a very very soft metal. So you know what will happen if you hook it up to something that vibrates. HTH. Larry Mac Donald lm4@juno.com Rochester N.Y. Do not archive On Wed, 28 Feb 2007 08:10:25 -0600 "Russell Duffy" writes: Greetings, As I ponder my choices for mounting the single rotor engine, I noticed something that surprised me. 304 stainless is cheaper than 4130 steel. One thing that's always bothered me about steel tube type construction is the concern for rusting inside the tubes, so stainless is appealing. There must be a catch here. Is there a good reason I should use 4130 instead of 304? Either will likely be sized much larger than needed, since I don't have the means to do any proper analysis of the strength. Thanks, Rusty (Autoflight drive supposed to be shipping next week) ----__JNP_000_10dc.02bc.3666 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: quoted-printable Message

Hi Rusty,

There is a very good reason= for=20 using 4130 and NOT stainless.

Of course 4130 is always ready to get brittle but you can take care

of that by rosebudding your welds. And 4130 has the best strenght to <= /DIV>

weight ratio of all metals.

However,Stainless is a very very soft metal. So you know what will

happen if you hook it up to something that vibrates. HTH.
Larry Mac= =20 Donald
lm4@juno.com
Rochester N.Y= .
Do=20 not archive

On Wed, 28 Feb 2007 08:10:25 -0600 "Russell Duffy" <rusty@radrotary.com> writes:

Greetings,

As I ponder my = choices=20 for mounting the single rotor engine, I noticed something that surprised= =20 me. 304 stainless is cheaper than 4130 steel. One thing that'= s=20 always bothered me about steel tube type construction is the concern for= =20 rusting inside the tubes, so stainless is appealing. There must be = a=20 catch here.

Is there a good = reason I=20 should use 4130 instead of 304? Either will likely be sized much = larger=20 than needed, since I don't have the means to do any proper analysis of = the=20 strength.

Thanks,

Rusty (= Autoflight drive=20 supposed to be shipping next week)

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