From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] Re: Outboard elevator hinge bleeding
To: lml
Date: Tue, 20 Feb 2007 02:35:57 -0500
Message-ID: <web-1850504@logan.com>
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References: <016901c754bb$7e296c90$0301a8c0@Home>
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Posted for "John Barrett" <2thman@cablespeed.com>:

  Chris' video clip is very interesting.  I had not seen it before.  He does
  not include Carbinge in his test.  The fact is there is no play discernable
  in Carbinge when pulled back and forth as it appears he did in the video.
  In my observations, I have found the aluminum MS hinge material to also have
  a lot of play in the lateral plane as well - you can slide one side of the
  hinge back and forth on the pin while holding the other side.  This is not
  the case with Carbinge because we make them to tighter tolerance.  From the
  video it would be instructive to know how long the segment of hinge was in
  each sample and how much pressure was applied.
  
  Chris, can you supply that information?  I'd like to be able to duplicate
  the conditions you used for your test.
  
   You also stated that ".....Teflon and Nylon are very soft and will flow
  and deform if
  subjected to high loads."  Can you supply data you used to verify this
  comment as it applies to Nylon?  My data shows that when nylon is enclosed
  in a Carbinge hinge, it does not deform, even when subjected to over a
  million cycles.  I tend to agree with you that Teflon does flow
  significantly when point loads are applied, but I have not tested that
  theory myself.
  
  Regards,
  
  John Barrett

"""
   I seem to recall that Chris Zavatson posted a very detailed process for
  eliminating hinge looseness (and thus excess wear) a year or so ago.
   
   JHK
  
  [Rather than pointing everyone at a link I'm sure Chris wouldn't mind if I
  simply copied his post here...  good info is always worth multiple passes.
  Thanks to Chris for his frequent contributions here.  <M>   ]
  
  
  """This topic has had a fairly short cycle time on the LML, re-emerging
  relatively often. I follow these threads with interest since I tinkered with
  
  the hinge issue a couple of years ago. The result is an all metal solution
  that eliminates play far better than anything I have seen thus far. Wear has
  
  not been measurable yet, but I only have a few years and couple hundred
  hours
  on the parts. The details are online at:
  http://www.n91cz.com/HingePlay/hinges.htm
  In short, a standard MS hinge is reamed (hand reamer from McMaster) and then
  a
  larger diameter pin is used (SS welding rod).
  
  General conclusions:
  
  1.The standard MS hinge extrusion has a huge allowable tolerance for the
  hole
  diameter (.005"). Without modification, there is no single pin or insert
  that
  will both fit all hinges and not have play.
  http://www.n91cz.com/HingePlay/hinge_spec_1.jpg
  http://www.n91cz.com/HingePlay/hinge_spec_2.jpg
  
  2.The MS pin is undersized which adds to the tolerance in 1.
  http://www.n91cz.com/HingePlay/pin_spec.jpg
  
  2.Wear can be controlled by contolling the pin/hinge tolerance and
  clearance.
  
  3.Plastics such as Teflon and Nylon are very soft and will flow and deform
  if
  subjected to high loads.
  http://www.n91cz.com/HingePlay/sleeve-web.JPG
  
  
  How much play is acceptable is very difficult to quantitfy. Certainly less
  is
  better, in particular for non-mass balanced surfaces such as large trim
  tabs.
  The following video clip compares the play of various hinge options.
  http://www.n91cz.com/HingePlay/Hinge_Play_Test-low_res.WMV
  
  Chris Zavatson
  N91CZ
  360std
  www.N91CZ.com
  """