Getting Started; Balancing The Telescope; Inserting The Eyepiece - Orion AstroView 100 EQ Manual

Figure 4a.
Proper operation of the equatorial mount requires that the telescope tube be balanced on the R.A. axis. (a) With the R.A. lock lever released,
slide the counterweight along the counterweight shaft until it just counterbalances the tube. (b) When you let go with both hands, the tube
should not drift up or down. The telescope should be balanced in the Dec. axis already if you have properly centered the 1/4"-20 mounting
block on the optical tube relative to the tube rings.
thumbscrews on the housing, which is located at the rear
of the R.A. axis. Insert the front end of the polar finder (the
end without the eyeguard) into the housing so only about
1" of the polar finder extends from the back of the housing.
Do this slowly and with a twisting motion to prevent the
internal O-ring from becoming unseated. If it does become
unseated, you can remove the entire housing from the
mount to locate the O-ring and reseat it. This is done by
rotating the entire housing counterclockwise. Once the
polar axis finder scope is in the housing, tighten the three
thumbscrews. These thumbscrews will be used later to
align the finder with the mount's R.A. axis.
installing the Finder scope
To place the finder scope in the finder scope bracket, first
unthread the two black nylon screws until the screw ends
are flush with the inside diameter of the bracket. Place 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
adjustment screws while pulling the chrome, spring-loaded
tensioner on the bracket with your fingers (Figure 2b). Push
the finder scope through the bracket until the O-ring seats just
inside the front opening of the bracket cylinder. Now, release
the tensioner and tighten the two black nylon screws a couple
of turns each to secure the finder scope in place. Insert the
base of the finder scope bracket into the dovetail slot on the
top of the focuser. Lock the bracket into position by tightening
the knurled thumbscrew on the dovetail slot.

inserting the Eyepiece

Loosen the thumbscrew on the 1.25" eyepiece adapter (Figure
3) and insert the chrome barrel of the star diagonal into the
adapter. Then, loosen the thumbscrews on the star diagonal
Figure 4b.
and remove the small dust cap. Then insert the 25mm Sirius
Plössl eyepiece into the focuser and secure it with the thumb-
screws.
Your telescope is now completely assembled and should
appear as shown in Figure 1.

3. Getting started

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 R.A. 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 R.A. axis. Rotate it until the counterweight shaft
is parallel to the ground (i.e., horizontal).
2. Now loosen the counterweight lock knob and slide the
weight along the shaft until it exactly counterbalances the
telescope (Figure 4a). That's the point at which the shaft
remains horizontal even when you let go with both hands
(Figure 4b).
3. Retighten the counterweight lock knob. The telescope is
now balanced on the R.A. axis.
The telescope should be balanced in the Dec. axis already if
you have properly centered the 1/4"-20 mounting block on the
optical tube relative to the tube rings.
Now when you loosen the lock lever on one or both axes and
manually point the telescope, it should move without resis-
tance and should not drift from where you point it.
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