Orion 13039 User manual

Congratulations on your purchase of a quality Orion 2"
Crayford focuser. This focuser is intended for use with New-
tonian reectors. If you do not have a Newtonian reector, the
focuser may not be appropriate for your telescope.
Crayford focusers generally perform better than rack-and-pin-
ion models because the design reduces “focus shift”. Focus
shift is when an image moves position in the eyepiece when
it is being focused. This is very hard to eliminate in rack-and-
pinion focusers due to slight gear and tolerance imperfec-
tions which cause the drawtube to move slightly left or right
when focusing. For the Crayford design, the drawtube is
constantly tensioned (by the focusing shaft and four “roller
bearings”) so the drawtube cannot move perpendicular to the
desired motion.
Installation
This focuser was designed to be a “drop-in” replacement for
the 2" rack-and-pinion focuser that comes standard on Orion
reectors greater than 6" in aperture, including IntelliScope
and Classic Dobsonians. If you have one of these tele-
scopes, installing the 2" Crayford will be extremely easy. You
will need a Phillips head screwdriver and an adjustable cres-
cent wrench or pliers. Use the procedure outlined below:
Note:The SkyQuest XT8 Classic, or any size Classic style
XT Dobsonian manufactured before June 2002, are not
compatible with this focuser as a “drop-in” replacement.
If you have one of these telescopes please skip to the
paragraph following step 7.
1. Position your Newtonian reector optical tube so it is hori-
zontal. This will prevent any screws or nuts from falling
onto the primary mirror.
2. From the inside of the tube, secure one of the four focuser
securing nuts with the wrench or pliers.
3. Use the screwdriver to completely unthread the focuser
attachment screw from the securing nut currently being
held by the wrench or pliers.
4. Repeat this for the other three nut and screw pairs.
5. Remove the 2" rack-and-pinion focuser from the tube.
6. Place the 2" Crayford focuser where the rack-and-pinion
focuser was previously. Orient the focuser the same as
the removed one was. The through holes in the base of
the focuser should line up with the holes in the telescope
tube.
7. Reinstall the four screw and nut pairs using the wrench or
pliers and screwdriver. Tighten the screws rmly.
IN 300 Rev G 11/09
Orion 2" Crayford Focuser for
Newtonian Reflectors
#13039
Figure 1. The Orion 2" Crayford focuser for Newtonian reectors.
1.25" adapter
Focusing tension
adjustment set screw
Collimation screws
Focus wheel
Focus lock thumbscrew
Drawtube
Focusing shaft
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2021 Orion Telescopes & Binoculars. All Rights Reserved. No part of this product instruction or any of its contents
may be reproduced, copied, modied or adapted, without the prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY
INSTRUCTION MANUAL

If the focuser does not match the mounting holes on your
optical tube you will need to modify your tube so the focuser
will t. This will require drilling four holes into the tube for the
mounting screws. Use a 3/16" drill bit to do this. Use the base
of the focuser as a template when drilling these holes. You
may also need to cut a larger hole (3.65" diameter) in the
telescope for the bottom of the focuser. Be careful not to cut
your ngers on any sharp tube edges when attempting to do
this. Keep in mind that the minimum focus height for the 2"
Crayford focuser is approximately 70mm (without the 1.25"
eyepiece adapter attached), so if your eyepieces reach focus
closer to the tube than this, additional modications to the
telescope may be required.
Usage
Using the 2" Crayford focuser is very straightforward. Place
your 2" eyepiece in the focuser drawtube, and secure it in
place with the two thumbscrews. To focus, simply rotate one
of the focus wheels.
The large focus lock thumbscrew near the focusing shaft
(see Figure 1) locks the drawtube into position once focus
has been achieved. This is especially useful when using a
camera or heavy eyepiece in the focuser. Be sure this thumb-
screw is loosened when focusing.
The socket head set screw below the focus lock thumb-
screw adjusts drawtube focusing tension (see Figure 1). If
a heavy eyepiece causes the drawtube to move inward by
itself (drawtube tension too loose), or the focus wheels are
difficult to turn (drawtube tension too tight), then you will want
to adjust this set screw. This requires the 3mm hex key.
The 1.25" Eyepiece Adapter
In order to use a 1.25" eyepiece in the focuser, you must rst
install the 1.25" adapter. Place this adapter into the drawtube
like a 2" eyepiece, and secure it with the two thumbscrews on
the drawtube. Insert a 1.25" eyepiece into the adapter, and
secure the eyepiece with the thumbscrew on the adapter.
Collimation
The focuser has three pairs of socket head set screws and
socket head cap screws located on the base of the focuser
(see Figure 1). These “push-pull” screw pairs can be used to
tilt the focuser relative to the telescope tube for optical colli-
mation purposes. While these generally need no adjustment,
they are provided for extra convenience in case the need
should arise.
Optional Accessories
Some Newtonian reectors, specically Orion’s 8-inch f/4.9
or 10-inch f/4.7 reector telescopes, will require a longer 2"
eyepiece adapter for visual use with the Crayford focuser.
Without this optional adapter, you will not be able to reach
focus with eyepieces in these telescopes
To attach a SLR camera or digital imager featuring T-threads
directly to your focuser, an optional camera adapter is avail-
able from Orion.
You can also add convenient and precise electronic control
to your Crayford focuser with the Orion AccuFocus electronic
focuser.
Contact Orion Customer Service for ordering information.
Specifications
Focuser design: Crayford, accepts 2" eyepieces
and 1.25" eyepieces with included
adapter
Minimum focus height: 70mm without 1.25" adapter, 80mm
with 1.25" adapter
Focus travel: 40mm
Other features: Focus lock, drawtube focusing
tension adjustments, collimation
adjustments
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2021 Orion Telescopes & Binoculars.All Rights Reserved. No part of this product
instruction or any of its contents may be reproduced, copied, modied or adapted, without the
prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY
One-Year Limited Warranty
This Orion product is warranted against defects in materials or workmanship for
a period of one year from the date of purchase. This warranty is for the benet of
the original retail purchaser only. During this warranty period Orion Telescopes &
Binoculars will repair or replace, at Orion’s option, any warranted instrument that
proves to be defective, provided it is returned postage paid. Proof of purchase
(such as a copy of the original receipt) is required. This warranty is only valid in the
country of purchase.
This warranty does not apply if, in Orion’s judgment, the instrument has been
abused, mishandled, or modied, nor does it apply to normal wear and tear. This
warranty gives you specic legal rights. It is not intended to remove or restrict your
other legal rights under applicable local consumer law; your state or national statu-
tory consumer rights governing the sale of consumer goods remain fully appli-
cable.
For further warranty information, please visit www.OrionTelescopes.com/warranty.