Helios 9877 User Manual page 5

EQ-2
Balancing the Telescope:
stresses on the EQ equatorial mounts and to
ensure smooth, judder-free motion of the
telescope the instrument needs to be
balanced about both the declination and polar
(right ascension) axis. This is especially im-
portant if you propose to use a motor drive
for astrophotography at a future date.
(i) Locate the right ascension clamp and
loosen it whilst holding the telescope tube.
Turn the telescope about this axis until the
c o u n t e rweight bar is approximately horizontal.
GENTLY release your grip on the tube and
note if the counterweight has a tendency to
fall or rise: if it RISES, unlock the counter-
weight locking screw and slide it away from
the telescope; if it FALLS , slowly slide the
counterweight towards the telescope side of
the mount. Repeat this process until the
counterweight bar remains in one place with-
out support and clamp the counterweight
EQ-1
To eliminate
5
screw firmly - the telescope is now balanced
about the polar (right ascension) axis.
(ii) With the counterweight bar horizontal,
ensure that the right ascension clamp is
locked and unlock the declination clamp and
turn the telescope tube so that it is also hori-
zontal. As before, GENTLY release your grip
on the tube and note is there is a tendency for
one end to rise in the air.
the clamps holding the tube and slowly slide
the tube towards the end that rises. Lock the
tube clamp rings once more and see if the
telescope remains horizontal when so posi-
tioned. Repeat this process until the telescope
remains wherever you place it.
The telescope is now balanced about both the
declination and polar (right ascension) axes,
In due course you will add various acces-
sories to the telescope that will slightly alter
the balance position particularly if it is a cam-
era for astrophotography) in which case you
will have to go through processes (i) and (ii)
again, but for now you may care to mark the
balance points on the counterweight bar and
the telescope tube with small pieces of tape
for fast assembly in future.
AZ-3
I
f so, slowly loosen
EQ3-2