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5. Orient the equatorial mount as it appears in Figure
1, at a latitude of about 40°, i.e., so the pointer next
to the latitude scale (located directly above the lati-
tude lock t-bolt) is pointing to the hash mark at "40."
To do this, loosen the latitude lock t-bolt, and turn
the latitude adjustment t-bolt until the pointer and
the "40" line up. Then tighten the latitude lock t-bolt.
The declination (Dec.) and right ascension (R.A.)
axes many need repositioning (rotation) as well. Be
sure to loosen the R.A. and Dec. lock knobs before
doing this. Retighten the R.A. and Dec. lock knobs
once the equatorial mount is properly oriented.
6. Slide the counterweight onto the counterweight
shaft. Make sure the counterweight lock thumbscrew
is adequately loosened so the metal pin the thumb-
screw pushes against (inside the counterweight) is
recessed enough to allow the counterweight shaft to
pass through the hole in the counterweight.
7. With the counterweight lock thumbscrew still loose,
grip the counterweight with one hand and thread the
shaft into the equatorial mount (at the base of the
declination axis) with the other hand. When it is
threaded as far in as it will go, position the counter-
weight about halfway up the shaft and tighten the
counterweight lock thumbscrew.
8. Now attach the two slow-motion cables to the R.A. and
Dec. worm gear shafts of the equatorial mount by
positioning the setscrew on the end of the cable over
the indented slot on the worm gear shaft and then
tightening the setscrew.
3. Attaching a Telescope
The EQ-2 Equatorial Mount is designed to hold small to
mid-size telescopes weighing up to about 10 lbs. For
heavier telescopes, the mount may not provide suffi-
cient stability for steady imaging. Any type of telescope
can be mounted on the EQ-2, including refractors,
Newtonian reflectors, and catadioptrics, provided a
proper adapter or pair of tube rings is available to pro-
vide secure coupling.
Orion carries a variety of differently sized tube rings
and a 1/4"-20 mounting adapter designed exclusively
for the EQ-2 mount. One of these items will probably fit
the telescope tube you wish to mount. See the list of
Suggested Accessories at the end of these instruc-
tions, or check the Orion print or online catalogs for
currently available mounting accessories.
4
4. Balancing the Telescope
Once the telescope is attached to the equatorial mount,
the next step is to balance the telescope. Proper bal-
ance is required to insure smooth movement of the
telescope on both axes of the equatorial mount.
If you attach your telescope with a 1/4"-20 adapter, it
may not be possible to balance the scope precisely with
respect to the declination axis, because the telescope
cannot be adjusted back and forth as it can when tube
rings are used.
Assuming you will be using tube rings, we will first bal-
ance the telescope with respect to the R.A. axis, then
the Dec. axis.
1. Keeping one hand on the telescope optical tube,
loosen the R.A. lock knob. Make sure the Dec. lock
knob is locked, for now. The telescope should now
be able to rotate freely about the R.A. axis. Rotate it
until the counterweight shaft is parallel to the ground
(i.e., horizontal).
2. Now loosen the counterweight lock thumbscrew and
slide the weight along the shaft until it exactly coun-
terbalances the telescope (Figure 2a). That's the
point at which the shaft remains horizontal even
when you let go of the telescope with both hands
(Figure 2b). If you position the counterweight all the
way at the end of the shaft (near the retaining bolt
and washer) and it still does not counterbalance the
telescope, you will need to purchase an additional
counterweight (Orion part number #65024).
Retighten the counterweight lock thumbscrew. The
telescope is now balanced on the R.A. axis.
3. To balance the telescope on the Dec. axis, first tight-
en the R.A. lock knob, with the counterweight shaft
still in the horizontal position.
4. With one hand on the telescope optical tube, loosen
the Dec. lock knob (Figure 2c). The telescope should
now be able to rotate freely about the Dec. axis.
Loosen the tube ring clamps a few turns until you
can slide the telescope tube forward and back inside
the rings (Figure 2d); this can be aided by using a
slight twisting motion on the optical tube while you
push or pull on it. Position the telescope so that it
remains horizontal when you carefully let go with
both hands (Figure 2e). This is the balance point for
the Dec. axis. Before clamping the rings tight again,
rotate the telescope so the eyepiece is positioned at
a convenient angle for viewing (this is not possible if
using a 1/4"-20 mounting adapter).
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