Orion starBlast 4.5 EQ - Manual (Page 5)

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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 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 of the telescope
with both hands (Figure 4b).
3. Retighten the counterweight lock knob. The telescope is
now balanced on the R.A. axis.
4. To balance the telescope on the Dec. axis, first tighten the
R.A. lock knob, with the counterweight shaft still in the hori-
zontal position.
5. With one hand on the telescope optical tube, loosen the
Dec. lock knob. The telescope should now be able to rotate
freely about the Dec. axis. Loosen the knurled tube ring
clamps a few turns, until you can slide the telescope tube
forward and back inside the rings (Figure 4c). Using a slight
twisting motion on the optical tube can help move the tube
within the rings.
6. Position the telescope so it remains horizontal when you
carefully let go with both hands (Figure 4d). This is the
balance point. Before clamping the tube rings tight again,
rotate the telescope so the eyepiece is at a convenient
angle for viewing. When you are actually observing with
the telescope, you can adjust the eyepiece position by
loosening the tube rings and rotating the optical tube.
7. Retighten the tube ring clamps.
The telescope is now balanced on both axes. Now when you
loosen the lock knob on one or both axes and manually point the
telescope, it should move without resistance and should not drift
from where you point it.
Focusing the telescope
With the 15mm Expanse eyepiece in the focuser, move the tele-
scope so the front (open) end is pointing in the general direction
of an object at least 1/4-mile away. Now with your fingers, slowly
rotate one of the focusing knobs until the object comes into sharp
focus. Go a little bit beyond sharp focus until the image starts to
blur again, then reverse the rotation of the knob, just to make
sure you’ve hit the exact focus point.
Figure 4. Proper usage of the equatorial mount requires the telescope tube to be balanced on both the R.A. and Dec. axes. (a) With the
R.A. lock knob 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. (c) With the Dec. lock knob 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.
4b. 4a.
4c. 4d.