Last updated: 27 November 2007
Subject:	etx125 counterweight
Sent:	Tuesday, November 27, 2007 10:34:27
From:	Glenn Craig (
Here is the counterweight I fashioned out of some scraps of steel and a
few lead fishing-weights.  It weighs 3.25 lbs, and keeps the etx in a
neutral position (the photo shows the telescope at its balance-point)
although to be most effective it would have to be in a much more complex
arrangement that I just didn't feel was worth the effort.

The steel parts cross in a T after the curved one is carefully pounded
and fitted to the available dimensional tolerances.  Some of the steel
on the bottom edge still had to be removed, as it just barely scraped
the plastic housing.  The lead was melted on the kitchen stove into a
small pot and poured into a long flat rectangular mold made of folded
roof-flashing.  Then, using a soft hammer was curved to fit the steel
frame and epoxied in.

I had lots of epoxy left over to brush on the lead, making a
surface-covering that is not toxic.  Lead is nasty stuff, but it's about
the only thing that will work in such close quarters.

The etx is much more stable at all elevations and doesn't require so
much force on the right-hand engagement screw.  But at the higher
magnifications there is still that bouncing that has me thinking about
some sort of gyroscopic stabilizer......hmmm.  Might work.  -gc



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