[ATM] Virtual Counterweights

["Jack Swaton @ Starry Host" <jswaton@starryhost.com>]

My OTA (wooden, octagonal, closed tube) should be done tomorrow. My thanks
to all for the sucessful coaching on how to make an octagonal tube.
 
I'm now looking for ideas for virtual counterweights. The mount  will have
the altitude axis at the eyepiece so the eyepiece remains at a constant
height to save my aching back.
 
Since I only have 5 inches or so on the upper OTA past the leverage point
and a heavily cantelevered weight representing the lower OTA (about 49" or
so), I don't really want to use more dead weight as counter balance slung
out 5 feet in space on an iron bar. I'd rather use springs, pulley's or ???.
My current design uses springs similar to Tom Krajci's et al:
http://education.gsu.edu/spehar/FOCUS/Astronomy/krajci/krajci.htm.
 
The rest of the mount is planned as a very tall pillar with short tripod
legs on the lower end. The fork on the upper end will have 3 lazy susan
bearings, one on each fork (left and right) and one on the azimuth base
which of course sits on top of the pier.
 
Thoughts?
 
Thanks,
Jack
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