From: "Bob May" 
To: "atmlist" 
Reply-To: "Bob May" 


Palm trees to have a tendency to sway in the wind, I know because I used to
climb them when I was a kid for the coconuts. The twin motor idea is to
take the slop out of the drive.  The second motor is used to provide a load
against which the first worked.  This works well when the motors are
basically in a stalled condition and could be driven backwards without
failure.  The system is common on gun, radar and other mounts that need to
be pointed in a very accurate direction.  I used to work on a radar system
in the Navy that used the method.  The pointing was quite accurate and
smooth and yet the system could drive the mount at more than 50rpm if
needed.
Bob May
http://nav.to/bobmay
bobmay{at}nethere.com
NEW! http://bobmay.astronomy.net

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