Received-SPF: pass
 receiver=logan.com; client-ip=64.136.30.75; envelope-from=alwick@juno.com
To: flyrotary@lancaironline.net
Date: Thu, 1 Dec 2005 16:54:21 -0800
Subject: Re: [FlyRotary] Re: fuel/brake lines
Message-ID: <20051201.165449.3112.2.alwick@juno.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
From: al p Wick <alwick@juno.com>

One of the businesses I worked for made tubing components for trucks. One
interesting effect, that we don't see, is that the tubing actually turns
into "S" shape when the engine is running. So it's most valuable to have
soft hose ends where it mates with solid objects. This reduces fatigue
stresses. If you can ever borrow a strobe light, it's fascinating.
Objects you think are straight, are actually sine wave. Valuable way to
reduce this effect is to use wire ties every 6" or so. That changes the
vibration frequency. Take a look at your car. You won't be able to find
any wire, or tube without wire tie or other restraint each 6".

I had to resolve Million $ warranty claim caused by design engineer not
familiar with need to tie tubing down every 6". He hard mounted it. It
then broke right next to the mount. Pretty typical failure.

FWIW.


-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html


On Thu, 01 Dec 2005 17:52:12 -0500 Ernest Christley
<echristley@nc.rr.com> writes:
> Ed Anderson wrote:
> 
> > Having had aluminum brake line tube fail from fatigue,  causing a 
> 
> > uncommanded departure from the runway, resulting in a fireball 
> which 
> > ignited my wheel pant, I would suggest you consider "real" brake 
> lines 
> > (SS braided with Teflon lining).   But, just a personal opinion of 
> 
> > course.
> >
> ...and a good one at that.  My plan is to run the aluminum 'in the 
> middle'.  I'll have a real line from the reservoir to the master 
> cyliner, and then to an anchored bulkhead fitting.  The aluminum 
> picks 
> it up from there, running to a T and across to each wheel where it 
> terminates in another anchored bulkhead fitting at the outer main 
> gear 
> pivot blocks.  Real lines pick it up to carry it down to the 
> calipers.  
> I think this is the best compromise for weight, cost, and easy 
> maintenance.  I'd want to have each of those fittings and anchor 
> points 
> even if I ran the real brake line everywhere.
> 
> -- 
>          ,|"|"|,                                    |
> ----===<{{(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/
> 
> 


-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html