Orion SKYQUEST XX12 - Manual (Page 14)

14
to the truss connectors (see Figure 23). This should rarely
need to be done.
The telescope is now assembled and ready to be placed into
the Dobsonian base. To disassemble the tube, completely
unthread the truss connector knobs from the upper truss sup-
port ring while holding the upper tube section. Then, unthread
the truss poles from the lower truss support ring.
connecting the optical tube to the Dobsonian
Base
Now that the base and tube are assembled, it is time to con-
nect them together.
1. Lift the optical tube and gently place it into the Dobsonian
base so the altitude bearings on either side of the tube rest
on the base's bearing cylinders. Be careful when doing
this, as the optical tube is somewhat heavy and unwieldy.
Orient the optical tube on the base as seen in Figure 1.
Make certain the optical tube does not get hung up on
the vertical stop or the CorrecTension pads (i.e. the three
square white pads on the inward-facing surface of the left
side panel) as you put it in place. Also, be very careful
not to hit the altitude encoder with the side bearing on
the tube when doing this or damage to the encoder could
result. The bumper helps to prevent such contact. Once
on the bearing cylinders, the tube should pivot freely up
and down with gentle hand pressure. Note that the tube
will not yet be properly balanced, since the eyepiece and
finder scope are not in place, and the altitude tensioning
knob has not been installed.
2. Select one of the altitude tensioning knobs and slide
the tensioning metal washer onto shaft, followed by the
tensioning white Teflon washer (you will need to thread
the Teflon washer onto the shaft, this keeps both wash-
ers captive on the knob’s shaft). These parts are found in
the box with the Dobsonian base. Push the shaft of the
knob through the hole in the side panel which has the
Figure 23. The position of the truss connectors relative to the
pole ends can be adjusted to register the truss connectors with the
upper truss support ring.
a. b.
Figure 24. When the knob in the truss connector is tightened,
it will clamp the truss connector against the registration flats on the
upper truss support ring.
Figure 25. The altitude tensioning knob, with metal and
Teflon washers attached, goes into the side of the base with the
IntelliScope port, and threads the tube’s altitude side bearing.
Figure 26. The other tensioning knob goes though the hollow
aluminum shaft of the altitude encoder and threads into the other
altitude side bearing on the tube.
Truss
connector
Button head cap screw
Truss
poles
Registration
flats
Upper truss
support ring
Truss connector knob
Truss
connector
IntelliScope
port
Altitude
side bearing
Altitude
tensioning
knob
Altitude tensioning
metal washer
Altitude tensioning
Teflon washer
Aluminum
shaft of
altitude
encoder
assembly Tensioning
knob
Right panel
Altitude side
bearing