Orion SkyQuest XT10 Classic Instruction Manual

INSTRUCTION MANUAL

Orion®

SkyQuest™ XT10 Classic

#9708 Dobsonian Reflecting Telescope

Providing Exceptional Consumer Optical Products Since 1975

Customer Support ( 80 0) 676-1343
E-mail: suppor t@ te le sc op e. co m

Corpo rate Off ices (831) 763- 700 0

P.O. Box 1815, Santa Cruz, CA 95061

IN 179 Rev. D 05/07

Secondary mirror holder with
4-vane spider (not visible)

Finder scope

Finder scope bracket

Eyepiece

Navigation knob

Right side panel

Front brace

Focus knob

Optical tube

Altitude side bearing

CorrecTension (XT)

Friction Optimization system

Handle

Top baseplate

Ground baseplate

2

Eyepiece rack

Primary

mirror cell

Left side panel

Foot (3)

Figure 1. The SkyQuest XT10

Welcome to an exciting new world of adventure! Your SkyQuest XT10 Dobsonian is a high-quality opti-

cal instrument designed to bring you dazzling views of the outer reaches of our universe. With special
new innovations, such as the CorrecTension (XT) Friction Optimization system, large format focuser,
and deluxe accessory package, this telescope represents a giant leap forward in the evolution of the
Dobsonian. Whether you are brand-new to amateur astronomy or a seasoned stargazer, the SkyQuest
XT10 Dobsonian will provide many evenings of enjoyment and fascination.

Table of Contents

1. Unpacking. . . . . . . . . . . . . . . . . . . . . . . . 3

2. Assembly . . . . . . . . . . . . . . . . . . . . . . . .

3. Using Your Telescope . . . . . . . . . . . . . . .

4. Collimation (Aligning the Mirrors) . . . . .

5. Astronomical Observing

6. Care and maintenance

. . . . . . . . . . . . 12

. . . . . . . . . . . . . 15

7. Specifications . . . . . . . . . . . . . . . . . . . .

4

7

10

16

WARNING: Never look directly at the

Sun through your telescope or its finder
scope—even for an instant—without
a professionally made solar filter that
completely covers the front of the
instrument, or permanent eye damage
could result. Young children should use this
telescope only with adult supervision.

1. Unpacking

The telescope will arrive in two boxes, one containing the
optical tube assembly and accessories, the other containing
the unassembled Dobsonian base. Be careful unpacking the
boxes. We recommend keeping the original shipping contain
ers. In the event that the telescope needs to be shipped to
another location, or returned to Orion for warranty repair, hav
ing the proper shipping containers will help ensure that your
telescope will survive the journey intact.

Make sure all the parts in the Parts List are present. Be sure
to check boxes carefully, as some parts are small. If anything
appears to be missing or broken, immediately call Orion
Customer Support (800-676-1343) or email sales@telescope.
com for assistance.

Parts List

Box #1: Optical Tube Assembly and Accessories

Qty. Description

1 Optical tube assembly

1 Dust cover

1 25mm Sirius Plössl eyepiece

1 10mm Sirius Plössl eyepiece

1 9x50 right-angle correct-image finder scope

1 Finder scope bracket with O-ring

1 4-hole eyepiece rack

1 Collimation cap

2 Eyepiece rack mounting wood screws (length 3/4")

2 Spring coils

2 Pull loops

4 Nylon spacers (black)

2 1/4" washers (black)

2 Phillips-head screws (black, length 1-3/4")

2 Screws with round knobs attached

Box #2: Dobsonian Base

Qty Description

1 Left panel

1 Right panel

1 Front brace

1 Top baseplate

1 Ground baseplate

12 Base assembly screws (length 2")

1 Hex key (4mm)

3 Plastic feet

-

3 Feet attachment wood screws (length 1")

1 Self-adhesive rubber bumper

­1 Large hex-head screw (length 3")

2 3/8" washers

1 3/8" lock nut

1 Nylon spacer (white)

1 T-nut

1 Handle

2 Socket head cap screws, 5/16" (black)

2 5/16" washers (black)

2 5/16" nuts (black)

1 Hex key (6mm)

3

Figure 2. Exploded view of the Dobsonian base.

C

C

B

D

J

A

F

I

H

K

L

E

G

3. Attach the two sides (C) with the front brace attached to
the top baseplate (D) with the remaining six base assem
bly screws in the predrilled holes. Tighten all six screws.

4. Tighten the six side screws installed earlier.

5. Insert the white nylon bushing (E) into the hole in the cen
ter of the top baseplate (D). Tap the nylon bushing in so it
goes all the way into the top baseplate. The nylon bushing
should be flush with the top surface of the top baseplate.

6. Insert the T-nut (K) into the center hole of the ground
baseplate (A) so the nut’s flanged top is on the same
side of the baseplate as the Teflon pads. Thread the large
hex-head screw (G) with a 3/8" washer (F) attached up
through the ground baseplate and through the T-nut until it
is tight. Now position the top baseplate (D) (with side pan
els attached) over the ground baseplate and lower it so the
screw goes through the nylon spacer in the center hole of
the top baseplate. Now thread the remaining 3/8" washer
(H) and lock nut (I) onto the screw’s shaft. You might need
to hold the screw’s head in place with another crescent
wrench or pliers. Tighten the lock nut with a wrench just
enough to allow a slight separation of the top and bottom
baseplates when the mount is lifted. The purpose of the
lock nut is merely to keep the two baseplates from com
ing apart when moving the telescope. Overtightening the
lock nut (I) will make the mount difficult to rotate in the
azimuthal (horizontal) direction.

7. Attach the handle (J) to the front brace (B) with the two
black socket-head cap screws. Insert the screws through
the handle and into the predrilled holes. Place the 5/16"
washers and 5/16" nuts on the protruding ends of the
screws. Tighten the nuts with a crescent wrench while
holding the screws stationary with the 6mm hex key.

-

-

-

-

2. Assembly

Now that you have unpacked the boxes and familiarized
yourself with all the parts in front of you, it’s time to begin
assembly. The optics of the telescope are already installed
in the tube, so most of the required assembly concerns the
Dobsonian base.

Assembly of the Dobsonian base

Refer to Figure 2 during base assembly. The base need
only be assembled once, unless you disassemble it for long­term storage. The assembly process takes about 30 minutes
and requires a Phillips screwdriver, an adjustable crescent
wrench, and the provided hex keys. When tightening screws,
tighten them until firm, but be careful not to strip the holes
by over-tightening. If you use an electric screwdriver, do final
tightening with a standard screwdriver to avoid stripping.

1. Screw the plastic feet into the underside of the ground
baseplate (A) using the self-tapping wood screws provid
ed, with a Phillips screwdriver. Insert the screws through
the feet and thread them into the predrilled starter holes.

2. Loosely attach the front brace (B) to the two side panels
(C) with six of the base assembly screws in the predrilled
holes. Use the 4mm hex key to tighten the screws. The
side panels should be oriented so the SkyQuest labels are
facing outward. The front brace should be oriented so the
index mark is facing inwards. Do not completely tighten
the screws yet.

Figure 3. Position the rubber bumper “stop” over the index mark

on the inside surface of the front brace.

-

8. The rubber bumper (L) provides a convenient “stop” for
the telescope’s altitude motion; it prevents the telescope
mirror cell from being knocked against the hard surface
of the base’s front brace. At the bottom of the interior sur
face of the front brace, you will notice a small index mark
engraved. Remove the backing from the rubber bumper
and position the bumper over the index mark, as shown in
Figure 3. Press firmly so the adhesive holds the bumper
securely in place.

-

4

Installing the Eyepiece Rack

The aluminum eyepiece rack is a standard accessory on
SkyQuest XT10 Dobsonians. It holds three 1.25" eyepieces and
one 2" eyepiece in a convenient place on the base, within easy
reach while you’re observing. A 1.25" barlow lens also can be
held in the rack. About halfway down the left side panel of the
base you will notice two predrilled starter holes, about 6" apart.
Take the black wood screws and thread them into the starter
holes with a Phillips screwdriver. Then you can “keyhole” the
eyepiece rack onto the wood screws and continue tightening
the screws (Figure 4). If you want to be able to remove the rack,
do not tighten the screws too tightly. Be certain that the screws
are loose enough that you can lift the rack and remove it from
the screws through the larger part of the keyhole. If you want to
have the rack permanently attached, thread the screws tightly.

Figure 4. Using the two supplied screws, install the aluminum

eyepiece rack in the predrilled holes about halfway down the left side
panel of the base.

Placing the Optical Tube on the Dobsonian Base

Lift the optical tube and set the altitude bearings on either side
of the tube in the “cradle” of the base (Figure 5). The unique
flange design of the altitude bearing allows for automatic left­to-right centering of the optical tube in the cradle. Once in the
cradle, the tube should pivot freely up and down with gentle
hand pressure. Note that the tube will not yet be properly bal
anced, since the eyepiece and finder scope are not in place,
and the CorrecTension system has not been installed.

Figure 5. Set the optical

tube on the “cradle” of the
base so that the altitude side
bearings on the tube rest on
the white plastic “pads.”

SkyQuest XT10 Dobsonians employ a simple yet effective
remedy for the friction problem that obviates the need for
such cumbersome countermeasures. CorrecTension Friction
Optimization utilizes a spring coil to “pull” the tube assem
bly down onto the altitude bearing pads, thereby increasing
the friction by just the right amount. With CorrecTension, you
can change eyepieces or add a barlow lens without having to
tediously adjust the telescope’s balance as you would with other
Dobsonians. The altitude friction will roughly equal the azimuth
friction, ensuring optimal performance.

To install the CorrecTension assembly, follow these steps while
referring to Figure 6:

1. Put one of the black nylon spacers on a black Phillips head
screw. The spacer should be oriented so the narrow end
seats against the head of the screw. Slip one of the black
1/4" washers over the end of the screw. Now, thread the
screw into the hole in the base side panel just below the cra
dle. The screw will thread into the preinstalled insert in the
hole. Use a Phillips screwdriver to tighten the screw. Repeat
this procedure on the opposite side panel.

-

Altitude side bearing

-

-

Installing the CorrecTension (XT) Friction
Optimization System

Perhaps the most exciting new feature of the SkyQuest XT10
Dobsonian is the CorrecTension Friction Optimization sys
tem. Because of their relatively light weight, 10" and smaller
Dobsonians have always been plagued by insufficient friction
on the altitude bearing surfaces. As a result, such telescopes
move up and down much too freely. This causes problems
when the obser ver tries to accurately center and track an
object for viewing, especially at higher powers. Also, the tele
scope becomes very sensitive to balance, requiring additional
equipment such as counterweight systems or adjustable side
bearings to compensate.

Screw w/round knob

-

Spring

Phillips head
screw (black)

Pull loop

-

Figure 6. Close-up view of the CorrecTension system.

Black nylon

spacers

1/4" washer

(black)

5

Dobsonian base. The springs will remain captive on the alti­tude side bearings, so they will not get lost.

Installing the Finder Scope

The SkyQuest XT10 comes with a high-quality 9x50 right­angle correct-image achromatic finder scope (Figure 8a) as
standard equipment. A finder scope greatly aids in finding
objects to view in the night sky, which will be discussed in
detail later. The “9” denotes the finder scope’s 9 power magni­fication while the “50” means it has a 50mm diameter lens.

a.

b.

Figure 7. (a) To attach the spring to the base, grip the pull loop

with your index finger and pull down on the spring. (b) While pulling
down, slip the end ring of the spring over the screw head and onto the
narrow part of the nylon spacer, then release the pull loop.

Focus lock ring

Finder scope bracket

Alignment thumbscrews

Correct-image
prism housing

Tensioner

Figure 8a. The 9x50 right-angle correct-image finder scope.

The finder scope arrives pre-installed in its bracket, but must
be placed into the dovetail holder on the telescope tube. Slide
the base of the finder scope into the dovetail holder located
adjacent to the focuser (Figure 8b). Lock the bracket into posi­tion by tightening the knurled thumbscrew on the dovetail
holder.

2. Next, insert one of the screws with round plastic knob
attached through the end ring of one of the springs. Slip
a black nylon spacer onto the screw. Orient the spacer so
the narrow end is closest to the knob. Thread the entire
assembly into the hole in the center of the telescope’s alti­tude side bearing until tight. The end ring of the spring
should seat onto the narrow end of the spacer. Repeat this
procedure for the other altitude side bearing.

3. Attach a pull loop to the free end of each spring. Slide
the loop through the opening in the ring on the end of the
spring.

4. Now, pull each spring down using the pull loop, and posi­tion the spring’s end ring over the head of the Phillips
screw (installed in step 1) and onto the narrow part of the
nylon spacer, as shown in Figure 7. You needn’t attach
both springs simultaneously; one at a time is fine.

The CorrecTension system is now installed and engaged.
If you wish to remove the telescope from the base, you will
first need to disconnect the springs from the “posts” on the

6

Finder scope bracket

Knurled thumbscrew

Dovetail holder

Figure 8b. Inserting the finder scope into its dovetail holder.

Inserting an Eyepiece

The final step in the assembly process is to insert an eye­piece into the telescope’s focuser. Take the cover cap off the
end of the focuser drawtube. Loosen the thumb screw on the

1.25" eyepiece adapter (see Figure 9). Do not loosen the two
thumb screws on the 2" eyepiece adapter. Insert one of the
supplied eyepieces, then secure it by retightening the thumb