Installing the Light Shroud

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 SiO2 overcoat

The #27190 SkyQuest XX12 Truss Tube Dobsonian includes

acustom-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!