Orion ATLAS 10 EQ 9874 - Manual (Page 5)

the O‑ring that comes on the base of the bracket over the body
of the finder scope until it seats into the slot on the middle of
the finder scope. Slide the eyepiece end (narrow end) of the
finder scope into the end of the bracket’s cylinder opposite
the alignment screws while pulling the chrome, spring‑loaded
tensioner on the bracket with your fingers (Figure 3b). Push
the finder scope through the bracket until the O‑ring seats
just inside the front opening of the bracket cylinder. Release
the tensioner and tighten the two black nylon thumbscrews
a couple of turns each to secure the finder scope in place.
Insert the base of the finder scope bracket into the dovetail
holder on the top of the focuser. Lock the bracket into position
by tightening the knurled thumbscrew on the dovetail holder.
inserting the Eyepiece
Loosen the thumbscrew on the 1.25" adapter (Figure 4) and
remove the small dust cap. Insert the 25mm eyepiece into the
focuser and secure it with the thumbscrew.
Your Atlas 10 EQ is now fully assembled and should resemble
Figure 1.
note about the atlas 10 EQ Mount Weight
The Atlas 10 EQ mount is very heavy. Alone it weighs 54 lbs.
With the optical tube and counterweights it weighs over 120
lbs. Keep this in mind when moving the telescope even small
distances, and use assistance when needed. It is best to
remove the optical tube and counterweights when moving the
mount, or adjusting the length of the tripod legs.
4. Balancing the telescope
To ensure smooth movement of the telescope on both axes
of the equatorial mount, it is imperative that the optical tube
is properly balanced. We will first balance the telescope with
respect to the right ascension (R.A.) axis, then the declination
(Dec.) axis.
1. Keeping one hand on the telescope optical tube, loosen
the R.A. lock lever. Make sure the Dec. lock lever is locked,
for now. The telescope should now be able to rotate freely
about the right ascension axis. Rotate it until the counter‑
weight shaft is parallel to the ground (i.e., horizontal).
2. Now loosen the counterweight lock knobs and slide the
weights along the shaft until they exactly counterbalance
the telescope (Figure 5a). That’s the point at which the
shaft remains horizontal even when you let go with both
hands (Figure 5b).
3. Retighten the counterweight lock knobs. The telescope is
now balanced on the right ascension axis.
4. To balance the telescope on the declination axis, first
tighten the R.A. lock lever, with the counterweight shaft
still in the horizontal position.
5. With one hand on the telescope optical tube, loosen the
Dec. lock lever. The telescope should now be able to rotate
freely about the declination axis.
6. Loosen the knurled ring clamps on the tube rings a few
turns, until you can slide the telescope tube forward and
back inside the rings (this can be aided by using a slight
twisting motion on the optical tube while you push or pull
on it) (Figure 5c).
7. Position the telescope in the tube rings so it remains hori‑
zontal when you carefully let go with both hands. This is
the balance point for the optical tube
with respect to the
Dec. axis (Figure 5d).
8. Retighten the knurled rings clamps.
The telescope is now balanced on both axes. When you loos‑
en the lock lever on one or both axes and manually point the
telescope, it should move without resistance and should not
drift from where you point it.
5
Figure 4. The 2" focuser of the Atlas 10 EQ.
Focus lock
thumbscrew
Focus
knobs
1.25" eyepiece
adapter
2" eyepiece adapter
Collimation
screw pair
(3)
Figure 5a‑d. Proper operation of the equatorial mount requires
that the telescope tube be balanced on the R.A. and Dec. axes. (a)
With the R.A. lock lever released, slide the counterweights down
the counterweight shaft until they just counterbalance the telescope
tube. (b) When you let go with both hands, the tube should not drift
up or down (c) with the Dec. lock lever released, loosen the tube ring
lock clamps a few turns and slide the telescope forward or back in
the tube rings. (d) When the tube is balanced about the Dec. axis, it
will not move when you let go.
a. b.
c. d.