PSN-L Email List Message

Subject: Re: Lehman construction
From: BOB BARNS roybar@........
Date: Tue, 11 Jan 2000 15:46:20 -0500


Jim,
  If you have the magnet  of a Lehman, it may be attracted
to some magnetic material in the area, for example, steel reinforcing
rods in a concrete floor.  It doesn't take much iron nearby to cause a
problem.
Bob Barns

  

JIM MARTIN wrote:
> 
> Gentlemen,
> 
> Well, things seem to be going along quite nicely,  but I think I've hit a
> roadblock.  I can now setup the boom for a very repeatable 11sec period,
> but I just can't seem to coax anymore out of it.  I've tried tilting the
> base with the front screw and bringing the rear boom pivot point closer to
> the vertical plane of the wire pivot.  Just doesn't seem to want to slow
> down any more than about 11sec.
> 
> I am using a 1/2" dia.  threaded brass boom,  with a sharpened point on the
> pivot end.  This point is pivoting in a VERY small dimple at the end of a
> 3/8" bolt.  I even tried applying a small amount of lube to the pointed
> pivot,  in an attempt to reduce any friction.
> 
> Any suggestions?
> 
> Jim Martin
> 
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Larry Cochrane <cochrane@..............>