Slipping Declination Circle fix

by:    Clay Sherrod

Since I have been seeing numerous references of problems in
misalignment of declination setting circles, I thought I would pass on a
very easy yet rewarding tip to all ETX (and other scope) users out there; it doesn't
matter iwhat telescope it is, but all of us have been
frustrated by slipping declination setting circles.  Accuracy of
adjustment is important for not only finding deep sky objects in polar
mode, but also in the Alt-Az mode for critical alignment of the

We've all heard that Duct tape can fix anything....well telescopes
are not any exception.  The slippage of the declination circle on the
fork-mounted telescopes (the left fork arm) is due to lack of friction between the
circle locking knob and the metal circle itself.  However, too much
friction prevents accurate adjustment of circle if movement is necessary
(in case the reading gets off for whatever reason).  On the other hand,
the circle MUST rotate freely of the fork arm (arms, or it will bind the necessary movement in declination

The solution is duct tape.  Cut two (2) 1/2" wide by 1" long pieces of
duct tape and apply tightly to the inside of the flat perimeter of the
locking knob for the declination circle(s), so that the "shiny" surface
rests against the metal circle; reassemble the circle and knob to the
fork and your circle slipping is totally eliminated!  Nonetheless, the
duct tape (unlike other tapes) allows a very firm but smooth movement to
the circle should adjustment be necessary.  I have tried electrical,
plastic, surgical and binding tapes of all types, but plain old duct
tape is absolutely ideal to grip those slipping circles!

In the future, if fresh tape is desired because of wearing or adhesive
"bleeding," merely peel off the tape, remove the excess adhesive with
isopropyl (rubbing) alcohol, let dry, and apply a fresh strip.  I have
found that the life of the duct tape fix is better than one year of
heavy use.

Clay Sherrod

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