Mailing List flyrotary@lancaironline.net Message #35837
From: George Lendich <lendich@optusnet.com.au>
Subject: Re: [FlyRotary] Re: engine mount 4130 vs 304 SS
Date: Thu, 1 Mar 2007 17:33:23 +1000
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Rusty, I support Bill's comments.
The only place I would use SS is in the foot controls, it has to be bigger and thicker than 4130.
I love SS but wouldn't use it on any structural component - especially on an aircraft of any sort!
George ( down under)
Rusty,
4130 is simply a better material for an engine mount. Lynn's comments were pretty much on point, 4130 is stronger, harder and much tougher. Stainless usually only is truly rust resistant if passivated or electropolished after welding. The welding process brings some of the iron to the surface and the area around the weld will rust in the area of discoloration. Stainless is VERY subject to hydrogen embrittlement too. This can cause cracking on welded structures used in vibrating assemblys. 4130 isn't as subject to H2 embrittlement. So there are lots of reasons to use 4130. If the structure is suitably overbuilt this might not be a problem, but you better be sure of that. A engine mount failure is a VERY BAD thing on a autogyro.
Bill Jepson 
 
 
-----Original Message-----
From: rijakits@cwpanama.net
To: flyrotary@lancaironline.net
Sent: Wed, 28 Feb 2007 8:35 AM
Subject: [FlyRotary] Re: engine mount 4130 vs 304 SS

Ernest, 
 
"""> Thomas, I don't see the benefit of stainless being the protection of the 
> inside of the tube......"""" 
 
I don't like stainless at all , unless there is no workable alternative... 
 
Rusty wants the bling on the thing!! 
 
Thomas  
-- 
Homepage: http://www.flyrotary.com/ 
Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ 

AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com.
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster