ORION TELESCOPES & BINOCULARS AstroTrack 7812 User manual

IN 154 Rev. D 11/14
INSTRUCTION MANUAL
Customer Support:
www.OrionTelescopes.com/contactus
Corporate Offices:
89 Hangar Way, Watsonville CA 95076 - USA
Providing Exceptional Consumer Optical Products Since 1975
Copyright © 2014 Orion Telescopes & Binoculars
All Rights Reserved. No part of this product instruction or any of its contents may be reproduced, copied, modified or adapted,
without the prior written consent of Orion Telescopes & Binoculars.
Orion AstroTrack™
DC Motor Drive for EQ-1 Mount
#7812
The AstroTrack DC Motor Drive provides precise electronic, hands-free tracking of celestial
objects as they move across the sky. Designed for use with the Orion EQ-1 and Min-EQ
equatorial mounts, the AstroTrack counteracts the rotation of the Earth on its axis, making
objects appear to stand still in the telescope’s field of view. You won’t have to reposition the
telescope to re-center an object in the eyepiece as the object moves across the sky – a
welcome convenience!
The AstroTrack has variable-speed tracking control, allowing adjustment to the exact side-
real tracking rate as well as to speeds slightly slower or faster than sidereal. This ensures
accurate tracking of both solar system and deep-sky objects, and allows for correction of
any inherent deviation in the motor from the sidereal rate.
The AstroTrack provides sufficiently accurate tracking for piggyback and planetary (eye-
piece projection) astrophotography. It is not recommended for prime focus, long-exposure
photography.

2
Assembly
Installing the Battery
The AstroTrack is powered by a single 9-volt alkaline bat-
tery (not included). It should be installed before attaching the
AstroTrack to the equatorial mount.
Make sure the power switch is in the OFF position. Unscrew
the two thumbscrews on the front panel and remove the hous-
ing (Figure 1). You will notice a U-shaped foam liner inside.
Place the battery in the liner and snap on the terminal connec-
tor (Figure 2). Replace the housing, tucking the battery wires
inside so they’re not hanging out. Thread on the two thumb-
screws to secure the housing.
Use the same procedure to replace the battery when it runs
down. (You do not have to remove the AstroTrack from the equa-
torial mount.)
Installing the AstroTrack on the EQ-1
Equatorial Mount
When facing the front of the mount, the right ascension (R.A.)
slow-motion control cable should be mounted on the left end
of the R.A. worm gear shaft (see Figure 3). If it is mounted on
the right end, remove it from the mount, and reinstall it on the
left end of the shaft. Loosen the knurled thumbscrew on the
end of the motor’s drive coupler (see Figure 2).Use the pro-
vided large Allen wrench and remove the socket head screw
on the right side of the equatorial mount (see Figure 3).Orient
the motor drive so that the drive coupler slips over the right
end of the R.A. worm gear shaft. Now, attach the motor to the
mount by inserting the socket head screw through the slot in
the motor drive’s bracket, and re-threading it into the mount.
Tighten the thumbscrew on the end of the motor’s drive cou-
pler. The thumbscrew should seat into the groove on the end
of the worm gear shaft. You may need to rotate the R.A. worm
gear, using the R.A. slow-motion control cable for the thumb-
screw and the groove to line up.
Use the thumbscrew on the R.A. slow-motion control cable
as a reference to line up the drive coupler thumbscrew and
the groove on the worm gear shaft; when the thumbscrews
are rotationally aligned, the coupler’s thumbscrew should seat
into the groove on the shaft (see Figure 4). Once the thumb-
screw is tightened, the motor is engaged. When the motor
is engaged, never, under any circumstances, should you use
the R.A. slow-motion control cable! If you want to use the R.A.
slow-motion control cable, you must first loosen the thumb-
screw on the end of the motor’s drive coupler.
The motor is now properly installed on the EQ-1 mount, and
should appear as in Figure 5.
Operation
Quick Polar Alignment
For best results, the telescope’s equatorial mount must be
aligned parallel to the Earth’s rotational (polar) axis. The
AstroTrack will not track objects accurately (objects will not
stay in the field of view) if the mount’s R.A. axis is pointing to
the wrong part of the sky. An approximate polar alignment is
sufficient for most observing situations and is all that will be
covered here. For a more accurate alignment, consult your
telescope manual or detailed instructions in an observing
guide.
For observers in the Northern Hemisphere (north of the
Earth’s equator), alignment is achieved by aiming the mount’s
R.A. axis at Polaris, the North Star (see Figure 6). An eye-
balled approximation is all that’s necessary. Do this by sighting
along the R.A. axis from behind it while adjusting the latitude
adjustment on the tripod and repositioning the tripod itself,
until the R.A. axis is pointed toward Polaris. For observers in
Figure 3: The right ascension (R.A.) slow-motion control
cable needs to be mounted on the left end of the R.A. worm
gear shaft.
Figure 1: The front panel of the AstroTrack
Power
switch
Directional
switch
Power
light
Adjustable
speed
control
Front panel
thumbscrews
Terminal
connector
Figure 2: The interior of the AstroTrack. The battery goes in
the U-shaped foam liner and the terminal connector snaps on
the battery.
Knurled
thumbscrew
Drive
coupler
Set screw (attaches drive
coupler to motor shaft)
Foam
liner
9-volt
battery
R.A.
slow motion
control cable
R.A.
worm
gear
shaft Socket head
screw (for
bracket
attachment)
R.A. axis

3
the Southern Hemisphere, align on the star Sigma Octantis in
the constellation Octans.
Setting the Directional Switch
Before turning the power switch on, observers in the Northern
Hemisphere should make sure the directional switch is set to
N; Southern Hemisphere observers should set it to S.
Powering Up
To begin tracking, slide the power switch to ON. The red LED
power light should illuminate. If it does not, check the connec-
tion between the battery and the terminal connector.
Adjusting the Tracking Speed
The AstroTrack is equipped with adjustable speed control.
Turning the speed control knob clockwise increases the motor
speed, counterclockwise slows it.
Adjustable speed has several benefits. First, it allows you to
achieve a precise sidereal tracking speed for your telescope.
That’s the speed at which most celestial objects appear to
move across the sky. Second, it allows correction for any
deviation from sidereal rate that is inherent in the motor itself.
Third, you can track objects that move at a rate different from
sidereal. The Moon, for instance, moves at a slightly slower
rate, so the motor speed would be reduced.
How do you know when the tracking speed setting is “cor-
rect”? Essentially, when the object in the field of view of the
telescope doesn’t drift. There’s no need to spend a lot of time
precisely canceling the minutest amount of drifting: even with
a small amount of movement, an object will stay in the field of
view for a long period of time.
Using the Manual Slow-Motion Control
Before rotating the R.A. slow-motion cable on the EQ-1
mount, you must first disengage the motor drive.You must do
this whether the power switch is on or off. Disengage the drive
by loosening the coupler’s thumbscrew a few turns. The R.A.
worm gear should then rotate freely when you rotate the slow-
motion control or circular gear (and the coupler should remain
motionless). If you feel it “catch,” loosen the coupler’s thumb-
screw some more until the rotation of the shaft is unhindered.
To re-engage the motor drive, tighten the thumbscrew on the
coupler. Note, however, that to prevent slipping of the cou-
pler on the worm gear shaft, the coupler’s thumbscrew should
lock into the groove on the shaft. You may have to rotate the
R.A. worm gear (using the slow-motion control cable or circu-
lar gear) until the slot lines up with the thumbscrew. Use the
thumbscrew on the R.A. slow-control cable or the mark you
made on the circular gear for reference to line up the groove
and coupler’s thumbscrew. Then tighten the thumbscrew.
Figure 5: The AstroTrack installed on the EQ-1 mount.
Figure 4: When the thumbscrews on the R.A. slow-motion
control cable and the drive coupler are rotationally aligned,
the coupler’s thumbscrew should seat into the groove
on the R.A. worm gear shaft.
Thumbscrew
on R.A. slow-
motion control
cable
Thumbscrew
on drive
coupling
Big Dipper
(in Ursa Major)
Little Dipper
(in Ursa Minor)
N.C.P.
Pointer
Stars
Polaris
Cassiopeia
Figure 6: Use the constellation Ursa Major (the Big Dipper) to find Polaris (the North Star). Extend an imaginary line from
two “pointer stars” in the bowl of the Big Dipper, Travel down this line about five times the distance between the two pointer
stars and you will be at Polaris.

4
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 benefit 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
modified, nor does it apply to normal wear and tear. This warranty gives you specific legal rights. It is not
intended to remove or restrict your other legal rights under applicable local consumer law; your state or
national statutory consumer rights governing the sale of consumer goods remain fully applicable.
For further warranty information, please visit www.OrionTelescopes.com/warranty.
Orion Telescopes & Binoculars
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Customer Support: www.OrionTelescopes.com/contactus
Copyright © 2000-2014 Orion Telescopes & Binoculars
All Rights Reserved. No part of this product instruction or any of its contents may be reproduced, copied, modified or adapted, without the prior
written consent of Orion Telescopes & Binoculars.
Note Regarding Motor Interference with
the Mount:
It is not possible to point the telescope at all positions in the
sky with the AstroTrack installed. This is due to mechanical
interference with the motor and the telescope/mount. If you
wish to view these areas of the sky, you will need to remove
the motor from the mount. Do this by simply loosening the
thumbscrew on the drive coupler, and removing the socket
head screw that attaches the motor’s bracket to the mount.
Battery Life
A 9-volt alkaline battery provides about 35 hours of operation.
When the battery dies, the motor will slow noticeably and the
LED power indicator light will dim. When this occurs, remove
the old battery and install a new 9-volt battery.
Troubleshooting
If, when the AstroTrack is turned on, the telescope does not
move or is intermittent in its tracking, there are a few possible
causes.
1. Is the telescope properly balanced? The motor provides
only limited torque, so if the telescope is not balanced
on both the right ascension and declination axes, the
imbalance may put stress on the motor and inhibit the
smooth movement of the telescope.
2. Is the thumbscrew on the AstroTrack’s drive coupler
tight? If it is loose, the R.A. worm gear shaft may not be
turning at the same rate as the coupler, or may not be
turning at all. Make sure the thumbscrew is tight and is
seated in the groove on the end of the shaft.
3. Is the set screw that attaches the drive coupler to the
motor drive tight (see Figure 2)? If it isn’t, the coupler
may be slipping on the motor’s output shaft. Use a 2mm
Allen wrench to tighten the set screw, if necessary.
4. Weak or dead battery? Replace it with a fresh one and
try again.