No problem, Brett.  After the recent discussions, I thought it might be 
useful to those of you that are smart enough to understand, have the 
mechanical dexterity, equipment to build sensors and are not clumsy, broke 
and OLD, like me!
(smile).

Regards,
Jerry

--------------------------------------------------------------------------------

  ----- Original Message ----- 
  From: Brett Nordgren
  To: psn-l@..............
  Sent: Friday, June 11, 2010 3:47 PM
  Subject: Re: Wire & Metal Flexure Information


  Hi Jerry,

  That's a very useful article--new to me.  Thanks for sharing the link.

  One general comment:  While crossed-flexures such as those described
  in the article have very low torque and can be quite useful in a
  vertical instrument, for horizontal Lehman's and garden gates you
  could probably get away with a single thin (0.002"?) flexure clamped
  on edge with a length (gap between the two rotating parts) of 0.020"
  or perhaps even less.  Its only effect vs. the crossed-flexure design
  would be to require the tilt of the instrument to be changed very
  slightly to get the desired period, as the stiffer flexure would be
  providing a part of the restoring force normally provided by
  gravity.  And a single short flexure is likely to be much more rugged
  than a crossed-flexure pivot.

  Regards,
  Brett

  At 11:18 AM 6/11/2010, you wrote:
  >Here is an interesting article about flexures that may be of
  >interest to the group.
  >http://www.aspe.net/publications/Annual_2005/PAPERS/5FLEX/1859.PDF
  >
  >Regards,
  >Jerry


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  Public Seismic Network Mailing List (PSN-L)

  To leave this list email PSN-L-REQUEST@.............. with
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  See http://www.seismicnet.com/maillist.html for more information.







No problem, Brett.  After the recent discussions, I thought it =
might=20
be useful to those of you that are smart enough to understand, have the=20
mechanical dexterity, equipment to build sensors and are not clumsy, =
broke and=20
OLD, like me!
(smile).
 
Regards,
Jerry




  
----- Original Message ----- 
  From:=20
  Brett=20
  Nordgren 
  
To: psn-l@.............. 
  
Sent: Friday, June 11, 2010 =
3:47 PM
  
Subject: Re: Wire & Metal =
Flexure=20
  Information
  

Hi Jerry,

That's a very useful article--new to =
me. =20
  Thanks for sharing the link.

One general comment:  While=20
  crossed-flexures such as those described 
in the article have very =
low=20
  torque and can be quite useful in a 
vertical instrument, for =
horizontal=20
  Lehman's and garden gates you 
could probably get away with a =
single thin=20
  (0.002"?) flexure clamped 
on edge with a length (gap between the =
two=20
  rotating parts) of 0.020" 
or perhaps even less.  Its only =
effect vs.=20
  the crossed-flexure design 
would be to require the tilt of the =
instrument=20
  to be changed very 
slightly to get the desired period, as the =
stiffer=20
  flexure would be 
providing a part of the restoring force normally =
provided=20
  by 
gravity.  And a single short flexure is likely to be much =
more=20
  rugged 
than a crossed-flexure =
pivot.

Regards,
Brett

At=20
  11:18 AM 6/11/2010, you wrote:
>Here is an interesting article =
about=20
  flexures that may be of 
>interest to the group.
><http://www.aspe.net/publications/Annual_2005/PAPERS/5FLEX/1859.PDF">htt=
p://www.aspe.net/publications/Annual_2005/PAPERS/5FLEX/1859.PDF>http:/=
/www.aspe.net/publications/Annual_2005/PAPERS/5FLEX/1859.PDF
><=
BR>>Regards,
>Jerry


_________________________________=
_________________________

Public=20
  Seismic Network Mailing List (PSN-L)

To leave this list email =
PSN-L-REQUEST@...............
=20
  with 
the body of the message (first line only): unsubscribe
See =
http://www.seismicnet.co=
m/maillist.html=20
  for more information.