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Orion SKYQUEST XX12I User Manual

Page 2

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Section 2. Assembly – Connecting the Optical Tube to the
Dobsonian Base
The following text and images should be substituted for step 3
of this section and Figure 26 in the original instruction manual
(see pp. 14 and 15).
Find the 1-1/4"-long black plastic sleeve and slide it onto the
other tensioning knob’s threaded shaft as shown in Figure
26a below. Then insert the sleeved shaft into the hole in the
right side panel, as shown in Figure 26b. Thread the shaft
into the threaded hole in the telescope side bearing until the
knob is just barely tight. DO NOT OVERTIGHTEN or the plas-
tic sleeve could split or deform. There will be a ¼" gap or so
between the knob and the side panel – that is fine.
a.

b.

Figure 26.

Install the black plastic sleeve on the right-side

tensioning knob (a), then insert the sleeved shaft into the hole (b)

and thread it into the telescope side bearing until just barely tight.

Corrections to the SkyQuest XX12i IntelliScope

Instruction Manual (IN 339, Rev A)
Page

Section

Item

3

Introduction

Second sentence should read:
It’s a deep-sky observer’s dream
telescope, offering jumbo 12" optics
made from low-thermal-expansion
glass, a stylish base, and a sturdy
truss tube design that easily
disassembles into compact, portable
components.

26

Specifications Primary mirror specification should

read: 305mm diameter reflective
surface, low-thermal-expansion
glass, parabolic, center marked

Mirror coatings specification should
read: Enhanced-reflectivity (94%)
aluminum with SiO

2

overcoat

Installing the Light Shroud
The #27190 SkyQuest XX12 Truss Tube Dobsonian includes
a custom-designed Light Shroud (#15097). For the best per-
formance from any truss Dobsonian, a shroud is a must. This
one, custom designed for the SkyQuest XX12, is made of a
stretchy nylon blend material that fits like a glove over the truss
poles of the XX12, fastening with thick elastic bands on both
ends. The water-resistant, opaque black fabric blocks stray

light from entering the optical path, thus improving image con-
trast. It’s also breathable, which minimizes unwanted vibra-
tion of the scope in breezy conditions. Use of the shroud will
lessen the accumulation of dust and dirt on the mirrors during
use, and will help prevent dew from forming on them.
To install the shroud, first remove any accessories from the
upper tube section, such as the eyepiece and finder scope,
and rack the focuser drawtube all the way in. Then stretch
open the elastic band on one end of the shroud and slip it
over the upper tube section and onto the truss pole assembly.
Then stretch open the elastic band on the other end of the
shroud and slip it over the upper tube section, to just above
the upper truss support ring; that is, just above the truss pole
connectors. Now stretch the bottom end of the shroud over
the lower truss support ring and pole connectors. The installed
shroud should now resemble the picture above.
Now you’re all set to observe!