Orion 23013, 23016, 23017, 23019, 23020 Instruction Manual

INSTRUCTION MANUAL

Orion® Premium

Deep Space Explorer

10" & 12.5"

#23013, #23016, #23017, #23019, #23020, #23022

Dobsonian Reflecting Telescope

™

Providing Exceptional Consumer Optical Products Since 1975

10"DSE

12.5" DSE

2" Low Profile

Focuser

#23013

NA

1.25" Rack & Pinion
Focuser

Customer Support [phone]
E-mail: [e-mail]

Corporate Offices [phone]

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

#23022

NA

2" Rack & Pinion

Focuser

#23019

#23020

2" Crayford

Focuser

#23016

#23017

IN 055 Rev B 0199

Congratulations on purchasing an Orion Premium Deep Space Explorer telescope! It is a precision

instrument designed exclusively for astronomical observation. With its enhanced Newtonian optical sys­tem and its easy-to-use Dobsonian mount, you’ll enjoy countless views of fascinating celestial objects.

If you have never used a telescope before, we would like to welcome you to amateur astronomy. Take
some time to familiarize yourself with the night sky. Learn to recognize the patterns of stars in the major
constellations. With a little practice, a little patience, and a reasonably dark sky away from city lights,
you’ll find your telescope to be a never-ending source of wonder, exploration, and relaxation.

Table of Contents

1. Important Points About Your Telescope ............................................................................... 2

2. Terminology ......................................................................................................................... 2

3. Assembly ............................................................................................................................. 3

4. Using Your Telescope ........................................................................................................... 4

5. Collimation of the Optics (Aligning the Mirrors) ................................................................... 6

6. Observing Tips and Techniques .......................................................................................... 8

7. Astronomical Viewing ........................................................................................................... 9

8. Care and Maintenance ...................................................................................................... 10

9. Specifications ....................................................................................................................... 11

1. Important Points About
Your Telescope

To get the most out of your new telescope, take the time to read
this instruction manual thoroughly. The following suggestions, in
particular, should be heeded.

1. Never look directly at the Sun without a proper, professionally
made solar filter. Doing so could cause permanent eye dam­age or even blindness. Never use a dark-glass solar filter that
threads into an eyepiece; it may crack under the intense heat
that builds up at the focal plane.

2. Like all reflector telescopes, performance is best after the tele­scope has cooled to the outdoor temperature for at least an hour
(longer in colder climates). If possible, store the telescope in a cold
place, such as a garage, to minimize the cooling time. It’s best to
observe with low powers until the telescope has equilibrated.

3. Observe from a dark location, away from street and porch lights.
Your eyes take 10 to 30 minutes to adapt to the darkness. Use a
red-filtered flashlight to preserve your dark-adapted night vision; a
white light can greatly and instantly reduce your low-light sensitivity.

4. Keep your telescope’s mirrors in good optical alignment (col­limation). The technique for collimation is easily learned (see
section 5). Adjustment is required only occasionally, and
performance will be noticeably improved.

5. Never lubricate the bearing surfaces of your Dobsonian tele­scope. Doing so reduces the bearing friction and causes the
telescope to move too freely. The inherent friction of the bearing
surfaces is an important part of the telescope design.

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.

2. Terminology

Altitude Bearings The two round hubs on opposite sides of the

optical tube, which rest in the cradle of the Dobsonian base. They
allow the telescope to be pivoted up or down (altitude).

Altitude Bearing Pads The pads of material on the Dobsonian

cradle where the optical tube altitude bearings rest.

Azimuth Pads The white Teflon pads between the two base plates,

which allow the telescope to be moved side to side (azimuth).

Azimuth Pivot Bolt The bolt through the center of the two base-

plates, which serves as a pivot point for azimuthal rotation.

Collimation Alignment of the optical elements of an instrument.

Proper collimation is necessary to achieve peak optical performance.

Ground Baseplate On the Dobsonian base, the round board

closest to the ground. It often has “feet” on the underside and three
azimuth bearing pads on the perimeter of its upper surface.

Dobsonian Mount A type of simple, cabinet-style altazimuth

mount for a Newtonian reflector, invented by John Dobson of the
San Francisco Sidewalk Astronomers club.

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Ebony Star Pebbly Formica surface on the azimuth axis on

which the Teflon pads make contact, providing buttery smooth
movement.

Eyepiece A lens-containing barrel that magnifies the image

formed by the telescope and allows your eye to focus on it.
Eyepieces of different focal lengths will produce different magni­fication factors.

Finder Scope A highly recommended optional accessory. It is a

small, low-power refracting telescope, usually with crosshairs, which
mounts on the optical tube of the main telescope to aid in pointing
the telescope. Its wide field of view facilitates the location of target
objects. When properly aligned with the main telescope, an object
centered in the finder scope will also be centered in the main tele­scope’s much narrower field of view.

Focuser A type of mechanical holder for the eyepiece that

enables the eyepiece to be moved in and out to achieve sharp
focus of the viewed image.

Optical Tube The main body of the telescope, which houses the

optics.

Optical Tube Handles Premium Deep Space Explorers come

with two handles to assist in lifting the optical tube onto and off of
the Dobsonian cradle. The handles are attached to the altitude
bearings on opposite sides of the optical tube.

Primary Mirror The large, concave mirror located at the back

end of the optical tube. It reflects incoming light to the secondary
mirror near the front of the tube.

Primary Mirror Cell The mechanical holder for the primary mir-

ror. It features alignment-adjusting bolts (usually three) that allow
exact positioning of the tilt of the primary mirror.

Secondary Mirror The small, elliptically shaped, flat mirror

located inside the optical tube beneath the focuser. Its function is to
divert the light transmitted from the primary mirror sideways into the
focusing tube.

Secondary Mirror Holder The mechanical holder for the sec-

ondary mirror; usually a single stalk or an adjustable multivane
“spider”.

Top Baseplate On the Dobsonian base, the uppermost of the

two round boards, which rests atop the ground baseplate. It sup­ports the vertical struts of the telescope tube cradle. The top
baseplate rotates on the ground baseplate, allowing the tele­scope to be moved in the azimuthal direction.

3. Assembly

Unpacking Your New Telescope

The telescope is packaged in three boxes, one containing the
telescope tube, another containing the optics, and the other con­taining the unassembled Dobsonian base and hardware. Exercise
care when unpacking the boxes. We recommend keeping the
original shipping containers; in the event that the telescope needs
to be shipped to another location or returned to Orion for war­ranty repair, having the proper shipping containers will help
ensure that your telescope will survive the journey intact.

Parts List

Qty. Description

1 Optical Tube

1 Primary Mirror Cell

1 Ground Baseplate

1 Top Baseplate

2 Cradle Sides

1 Cradle Front Brace

8 Wood Screws (socket-head)

4 Black Plastic Screw-head Caps

1 Azimuth Pivot Bolt

1 Cylindrical Nylon Bushing

1 Locking Nut

2 Nylon Washers

3 Wood Feet

3 Self-tapping Wood Screws (Phillips-head)

2 Optical Tube Handles

1 26mm Sirius Plössl Eyepiece (1.25" barrel diameter)

4 Primary Mirror Cell Mounting Bolts (socket-head)

2 Allen Wrenches

Assembly of the Dobsonian Base

Before the telescope can be used, the base must be assembled
(refer to Figure 1, page 11). This has to be done only once,
unless you disassemble the base for long term storage. The
assembly process takes about 15 minutes and requires a Phillips
screwdriver, the Allen (hex) wrench provided, and two 1/2" cres­cent wrenches, or a combination of a common wrench, crescent
wrench, or pliers.

Note: When tightening screws, tighten them by hand until firm,
but be careful not to strip the holes by overtightening. If you use
an electric screwdriver, do final tightening by hand.

1. Screw the wood feet into the underside of the ground base­plate (A) using the self-tapping wood screws provided, with a
Phillips screwdriver. Position the feet on the underside of the
ground baseplate from the preinstalled Teflon pads, directly
beneath them.

2. Loosely attach the front brace (B) of the cradle to the two
sides (C) with four of the eight socket-head wood screws in
the predrilled holes, using the large Allen wrench provided.
Do not completely tighten the screws yet.

3. Attach the two sides (C) to the top baseplate (D) with the
remaining four socket-head wood screws in the predrilled
holes. Tighten all four screws.

4. Tighten the four side screws installed in step 2, then press on
the black plastic screw-head caps.

5. Insert the nylon bushing (E) into the hole in the center of the
top baseplate (D). Tap the bushing so it goes all the way into
the top baseplate and part way into the ground baseplate (A).
The bushing should be flush with the top surface of the top
baseplate (D).

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6. Place a nylon washer (F) over the long pivot bolt (G), then
insert the bolt up through the bottom of the ground baseplate
(A) and through the nylon bushing. Now put on the remaining
nylon washer (H) and the locking nut (I). Tighten the nut just
enough to allow a slight separation of the top baseplate from
the ground baseplate when the mount is lifted. The purpose of
the nut is only to keep the two pieces from coming apart when
moving the telescope.

IMPORTANT! Overtightening the nut will make the mount
difficult to rotate in the azimuthal direction.

Installing the Optical Tube Handles

Premium Deep Space Explorers come with convenient handles
to help in lifting the optical tube onto and off of the Dobsonian
cradle. They also serve as levers for turning the telescope on the
azimuthal axis when the scope is pointed near the zenith (straight
overhead).

The handles attach to the altitude bearings (disks) on opposite
sides of the optical tube (refer to Figure 2). The handles should
be mounted in the center position on each of the bearings. Using
the provided Allen wrench, remove the bolt that resides in the
center hole.

To connect the handles to the altitude bearings, first remove the
nut and washer that is on the threaded shaft of each handle.
Insert the threaded shaft into the center hole in the altitude bear­ing. Rotate the handle clockwise until the shaft threads all the
way into the hole. Now, re-attach the nut and washer to the end
of the threaded shaft from the inside of the telescope. This will
require reaching up into the optical tube. This is easiest to do if
the telescope is resting on its side. Use a crescent wrench to
tighten the nut firmly.

Installing the Primary Mirror

Leave the protective covering on the primary mirror until just prior
to installing it in the telescope tube. This is a first-surface mirror
and, while tough enough to survive years of use without recoating,
it nevertheless must be handled with extreme care. Do not touch
the mirror’s aluminized surface or allow dirt and dust to build up on
it, as this could scratch the coating and compromise the optical
performance.

When you’re ready to install the mirror in the optical tube, follow
these steps:

1. Remove the protective tissue from the primary mirror. Set the
mirror cell on the floor in a clean room.

2. Carefully ease the tube over the mirror and mirror cell so that
the predrilled holes on the perimeter of the mirror cell line up
with the holes at the base of the optical tube.

3. With the socket-head mounting bolts and the large Allen
wrench provided, secure the mirror cell into place.

4. You’ll adjust the alignment of the primary mirror later, in
Section 5.

Placing the Optical Tube on the Dobsonian Base

Lift the optical tube by the handles on the altitude bearings and set
the tube down so the bearings rest in the “cradle” of the base, as
shown in the front cover picture. For the larger models, we recom­mend getting a friend to help lift the optical tube. Once in the
cradle, the tube should pivot freely up and down with gentle hand

pressure. Note that the tube may not be precisely balanced yet,
however, since the eyepiece is not in place. Proper balancing may
require the use of an optional counterweight system.

4. Using Your Telescope

Your Orion Premium Deep Space Explorer Dobsonian telescope
is one of the easiest telescopes there is to use. You will be sur­prised at the simplicity of operation, ease of manual tracking, and
exceptional optical performance. To get the most out of your
telescope, read this section carefully.

Use a Finder Scope

An optional finder scope is highly recommended to assist in aim­ing the telescope. It will help in locating objects and centering
them in the main telescope’s field of view. An 8x50 finder scope
or larger is recommended.

Your Premium DSE comes with two predrilled holes for an Orion
8x50 or 9x60 finder scope bracket. The holes are located a few
inches from the focuser. If you purchased an optional finder scope,
you will want to install it before using your telescope.

Hardware is not provided for attaching the finder scope since the
user could decide to put one of many different finder scopes onto
the Premium Deep Space Explorer, each of which might require
different nuts and bolts. For the Orion 8x50 or 9x60 finder scopes,
we recommend using 10-24 x 1" slotted machine screws and the
corresponding nut, accompanied with washers, to fasten the finder
to the main telescope. These items are available from any hardware
store. To minimize stray reflections, you can mount the finder scope
with the screws inserted from the inside of the tube out.

To install other finder scope models, you will need to drill the holes
yourself. Choose a position for the finder scope which is directly on
top of the telescope tube when the tube is aimed at the horizon, near
the focuser. Position the telescope tube so that it is lying horizontally,
parallel to the ground. Mark the spots for drilling mounting holes. Drill
holes the same size as the bolts being used. Be careful not to let
dust or debris fall onto the mirrors. You may want to cover the sec­ondary mirror with a soft tissue or a plastic bag while you are
installing the finder scope.

Aligning a Finder Scope

The finder scope and the telescope should be aligned to point to
exactly the same spot in the sky. Alignment is easiest to do in
daylight hours, before your observing session. Choose a treetop,
telephone pole, street sign—anything that is far off in the dis­tance, at least 200 yards away. Put that image in the center of the
field of your telescope’s eyepiece. Where is it in your finder
scope’s eyepiece? Hopefully, the image will be in the field of view
and some simple adjustments on the alignment screws of the
mounting bracket will put the image dead-center in the cross­hairs.

By loosening one alignment screw and tightening another, you
can change the line of sight of the finder scope. Continue making
adjustments to the various alignment screws until the image in
both the finder scope the telescope’s eyepiece is exactly cen­tered. Check the alignment by moving the scope to another
object and fixing the crosshairs on the exact point you want to
look at. Then look through the telescope’s eyepiece to see if that

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