ASTRO-PHYSICS 1600GTO Manuale utente
1600GTO German Equatorial Mount with
GTOCP4 Servo Motor Drive
Mounts Shipped
Starting in
November 2016
Astro-Physics, Inc.
11250 Forest Hills Road
Machesney Park, IL 61115
Telephone: 815-282-1513
Fax: 815-282-9847
www.astro-physics.com
August, 2018
Keypad Optional
1
ASTRO-PHYSICS
1600GTO GERMAN EQUATORIAL WITH
GTOCP4 SERVO MOTOR DRIVE
ABOUT THIS MANUAL 3
1600GTO PARTS LIST 4
MECHANICAL SPECIFICATIONS 5
INTRODUCTION 6
Why Polar Alignment is Important 6
ASSEMBLY DIAGRAM 7
PLAN AHEAD AT HOME 8
Handy Tools to Have on Hand 8
Quick Start Summary – New Installations 8
AT YOUR OBSERVING SITE 9
Assemble Pier (purchased separately) 9
Attach Polar Axis Assembly to Pier 9
Latitude Adjustment for 1600GTO German Equatorial Mounts 10
Special 90 Degree Alt-Azimuth Position 11
ASSEMBLY INSTRUCTIONS 12
Assembly of R.A. and Dec. Axes 12
Assembly Procedure: 12
Disassembly procedure: 13
CABLE MANAGEMENT 14
Preparation 14
The Basics 14
The Specics 14
Routing Cables if You Plan to Use the Cable Router Insert When Using the Polar Scope 15
Routing Cables if You Don’t Plan to Use the Cable Router Insert 16
ATTACH MOUNTING PLATE 17
Fixed Mounting Plate Options 17
Losmandy D-Style Compatible Saddle Plates 18
Astro-Physics Dovetail Option 18
Side-by-Side and Vixen Style Plate Options 19
Astro-Physics P-Style Compatible Saddle Plates 19
ATTACH COUNTERWEIGHT SHAFT AND COUNTERWEIGHTS 20
ATTACH MOUNTING RINGS AND SCOPE 20
UNDERSTANDING THE R.A. AND DEC. CLUTCH KNOBS 21
BALANCING THE TELESCOPE 22
Preliminary Balancing 22
Precision Balancing 22
Disengaging the Worm and Worm Wheel 22
2
ALTITUDE AND AZIMUTH ADJUSTMENTS – ROUGH POLAR ALIGNMENT 24
POLAR ALIGNMENT OPTIONS – FINE POLAR ALIGNMENT 25
Methods for ne polar alignment 25
Making Precise Altitude and Azimuth Adjustments 26
Fine Altitude Adjustment 26
Tips for Adjusting the Altitude 26
Fine Azimuth Adjustment 27
Precision-Adjust Rotating Pier Base with Azimuth Bearing 27
Using Software to Improve Pointing Accuracy 27
MISCELLANEOUS ITEMS 28
Bubble Level and Lanyard Post 28
Reference Orientation Lines 28
Warning for Dec. Servo Cable 28
SLEWING YOUR MOUNT IN BELOW FREEZING TEMPERATURES 29
AUTO-ADJUSTING GEARBOX - NO MORE WORM MESHING! 30
Checking and Adjusting the Gearbox Backstops in R.A. and Dec. 30
What to do if you believe that there is a backlash in the gearbox 31
SOME IMPORTANT NOTES 32
MOUNT CARE, CLEANING AND MAINTENANCE 33
Care 33
Cleaning and Touch-up 33
Routine Mount Maintenance 33
Worm Wheel Maintenance 33
TROUBLESHOOTING, TIPS AND SUPPORT 34
Troubleshooting and Tips 34
Additional Support 37
APPENDIX A: 1600GTO ABSOLUTE ENCODERS 38
Part numbers and description 38
What’s Included in the Kit 38
Absolute Encoder Cable Connections 38
APAE Utility 39
APPENDIX B: DECLINATION AXIS BACKLASH TESTS 40
PulseGuide™ 40
Dec Backlash Test 1 40
Dec Backlash Test 2 40
After Running Tests 1 and 2 41
Dec Backlash Test 3 41
MaxImDL™ 41
Step 1 41
Step 2 41
Step 3 41
APPENDIX C: MOUNTING PLATE FASTENER CHART 42
3
ABOUT THIS MANUAL
This version of the 1600GTO Manual was prepared for the production run of mounts that began shipping in November of
2016. Most of the information in this manual is applicable to all 1600GTO mounts that have been produced.
You should also note that this manual is actually one component of a three document system. In the past, we had two
manuals for each mount - one for the individual mount and another manual for the keypad that applied to all mounts.
Starting in the summer of 2011, we further divided the mount manuals to allow us to present the GTO Servo Motor Drive
System in greater detail. Like the Keypad Manual, the GTO Manual is universal to all mounts that use the Astro-Physics
GTO Servo Motor Drive System with the GTOCP4 Servo Control Box. This 1600GTO Manual, on the other hand, will
cover the 1600GTO’s mechanical features and physical operations.
Note: Some photos may differ slightly from the current mounts that are shipping.
As always, we highly recommend the Technical Support Section of our Web site for the latest information and for future
updated versions of this manual.
A nal note and an apology to our friends in the southern hemisphere. Many of the instructions in this manual are written
entirely from the point of view of those of us in the northern hemisphere. Since descriptive terms like left and right are
meaningless without a dened point of reference, we tend to use east and west to avoid ambiguity. The east and west
sides of a German equatorial mount are, of course, reversed in the southern hemisphere. At one point, our thought was to
always use phrases like the following: “... on the east side (west side in the southern hemisphere) ...” This quickly became
cumbersome and made the text more difcult to read. For simplicity, we decided to leave many of the explanations in
their northern hemisphere framework. To our southern hemisphere friends: We love you no less and apologize for this
unintended slight. We know, however, that you are all smart enough to make the necessary translation to “down under”
appropriate instructions. Thank you for your understanding.
Please RecoRd the Following inFoRmation FoR FutuRe ReFeRence
Mount Serial Number: _____________________________________________
GTOCP4 Serial Number: _____________________________________________
Keypad Serial Number: _____________________________________________
Purchase Date: _____________________________________________
4
1600GTO PARTS LIST
1 Polar Fork / Right Ascension Axis (R.A.) Assembly
1 Declination Axis (Dec.) Assembly
1 Dec. Top Plate (S1600DTP)
1 GTO Servo Control Box (GTOCP4)
1 22” x 1.875" Stainless Counterweight Shaft (M12601-E) with machined Safety Stop (M12676)
1 R.A. Cable Router Insert (M16145-A)
1 Mount to GTOCP4 Cable (CABGTOR19)
1 D.C. power cord set - 6’ cable with power pole connectors (CABPP6), 18” cable with cigarette plug (CABPP18C) and
18” cable with ring connectors (CABPP18R) and clip (FPCLIP)
1 15’ Straight-through Serial Cable (CABSER15)
1 Hex key Set
10 3/4” x 8” Velcro Cable tie wraps
1 CD containing: PEMPro™ v3 Software (written by Ray Gralak of Sirius Imaging) and PDFs of manuals
Instruction Manuals and Registration Card
Fasteners:
(6) 1/4-20 x 3/4” SHCS (for safety backup of dovetails)
(7) 5/16-18 x 5/8” SBHCS (pier adapter) (6 + 1 extra)
(7) 5/16” at washers (pier adapter)
In order to fully assemble your mount, you will need some of the following items sold separately.
Many of these items will be discussed throughout these instructions.
● 10” O.D. pier: Astro-Physics has several heights and styles to choose from.
● Counterweights: 5 lb. (5SCWT), 10 lb. (10SCWT), 18 lb. (18SCWT) and 30 lb. (30SCWT188) are available.
● Regulated Power Supply (110V AC to 12V DC converter): We recommend the Variable-volt, 25-amp supply
(PSVPW25A) for heavier loads and colder weather. The mount should have its own power supply.
● Portable rechargeable 12-volt battery pack: Several sizes and types are available from a variety of vendors.
Be sure that your battery pack can supply adequate power for an entire observing session! Please refer to power
requirements under Features and Specications on next page. We recommend having separate batteries – one for
the mount and one or more for all other accessories: camera, computer, dew removers etc. You may wish to consider:
○CP4 Powerpoles to Alligator Clips (CABPPAL) - For connecting the CP4 Power Cable to battery terminals.
○DC Inline Watt Meter and Power Analyzer (CABPPWM) - To monitor your power consumption.
Several additional options are available:
● Optional GTO Keypad controller with 15’ coiled cable. Hand-held computer to operate the mount without a PC and
additional software.
●9” Counterweight Shaft Extension (M12675): For heavier loads.
●Autoguiding accessories: Various guiding congurations can take advantage of the 1600GTO’s autoguider port.
The autoguider port receptacle (RJ-11-6) uses the industry standard SBIG ST-4 wiring setup.
●Pier accessory trays and support bars: Accessory Tray (TRAY10) and/or Eyepiece Accessory Trays (TRAY10H)
with Bi-Level (TRAYSB) or Single Level (TRAYSB1) Support Bars. Keep things close at hand.
●1600 Flat Surface Adapter (1612FSA): For attaching the 1600GTO to your own custom pier or tripod.
●1600 Flat Surface Adapter with Flat Pier Plate (1612FSA-FP): For attaching the 1600GTO to the Advanced
Telescope System (ATS) pier, or to your own custom pier or tripod when a at pier plate is needed.
●Polar Alignment Scopes: AP Right-Angle Polar Alignment Scope (RAPAS) and Losmandy Polar Alignment Scope
(PASILL4-179) – Many users nd a polar alignment scope useful for zeroing in on the pole quickly, particularly with
telescopes that are not orthogonal to the mount.
For a complete listing of our 1600GTO accessories, visit our Web site – www.astro-physics.com.
5
MECHANICAL SPECIFICATIONS
Construction All CNC machined aluminum bar stock, stainless steel, brass; stainless steel fasteners
Finishing and Assembly Every part is hand-nished and inspected. All assembly is done by hand, by highly skilled
mount assembly staff.
Worm wheel - R.A. & DEC. 10.3” (262 mm), 225 tooth aluminum
Worm gear - R.A. & Dec. 1.22” (31 mm) diameter, special low-wear alloy
Axis shaft - R.A. & Dec. 3.74” (95 mm) diameter
Shaft axis bearings - R.A.
& Dec. 5.71” (145 mm) diameter
Latitude range 0 to 78 degrees and 90 degrees for Alt-Az
Azimuth adjustment Approximately 13 degrees (± 6.5 degrees from center)
Counterweight shaft 1.875” (47.6 mm) diameter x 22” (559 mm) long, includes large machined safety stop knob;
weight: 17.2 lb. (7.8 kg). Optional 9” (229 mm) shaft extension available.
Weight of mount
R.A. axis / polar fork: 63.7 lb. (28.9 kg)
Dec. axis: 40.0 lb. (18.1 kg)
Dec. top plate 3.0 lb. (1.4 kg)
Capacity of mount
Approximately 220 lb. (100 kg) scope and accessories (not including counterweights),
depending on length. Recommended for refractors up to 250 mm, 18-20” Cassegrains,
Ritchey-Chrétiens and CDKs.
These are only guidelines. Some telescopes are very long for their weight or heavy for their
size and will require a larger mount. Remember also that imaging requirements are more
rigid than visual observation.
Instrument mounting
interface Reference the “Attach Mounting Plate” section of the manual.
Pier adapter base 9.775” (248.3 mm) diameter. The base is an integral part of the mount and azimuth
adjuster.
For a complete listing of the servo control, power, and periodic error specications, please see the
GTO Servo Drive System Manual.
6
INTRODUCTION
The 1600 German equatorial was designed to meet the needs of the advanced observer who requires a mount with
maximum strength and rigidity and minimum weight. The excess material in both axes has been carved out while retaining
a heavily ribbed structure for internal strength and rigidity. A unique dovetail was machined into the mating surfaces of
the R.A. and Dec. axes and also between the Dec. axis and the Dec. axis Top Plate. This feature allows quick and easy
assembly in the eld without any tools.
The DC servo motor drive with GTO computer system, the optional keypad with its digital display screen, and the included
AP V2 ASCOM Driver, PulseGuide™ and PEMPro™ v.3.x software all combine to offer extraordinary sophistication
for today’s observer. Whether you enjoy visual astronomy exclusively or plan an aggressive astrophotography or CCD
imaging program, this mount will allow you to maximize your night out under the stars.
The advanced keypad features allow you to slew automatically to objects in a wide range of databases as well as any R.A./
Dec. or Alt./Az. coordinate. A large selection of common names for stars and other objects makes your selection a snap.
The rapid slew rate of 5 degrees per second (1200x) allows you to locate objects very quickly and accurately. You will be
very pleased with the intuitive operation of this keypad. There are no complicated sequences of keystrokes to remember.
It is so easy to use that even if you don’t use it for a few months, you will feel at home with the keypad very quickly.
The keypad is only one way of controlling the versatile Astro-Physics GTO Servo System. From its very conception, the
servo controller was designed to work with any software that was written to use our published command set. We do not
lock you into any proprietary software or mandatory “additional” equipment. To increase the versatility of all our mounts,
we have developed and now fully support a V2 ASCOM Driver for use with all ASCOM client software.
As mentioned above, we also include PulseGuide™ mount control / utility software and a full version of PEMPro™
(Periodic Error Management Professional) v.3.x (latest version) for you to enhance your control and performance options.
As an added bonus, all 1600GTO mounts will come pre-loaded with the custom-tted PEMPro™ corrections from our
extensive individual testing that is performed on each and every mount. While the native periodic error of your 1600GTO
will be 5 arcseconds or less, you can reduce it even further to maximize performance without auto-guiding. These software
control products are detailed later in the manual.
In addition to everything outlined above, the 1600GTO’s control and performance options will be greatly enhanced by
the Astro-Physics Command Center (APCC). APCC fully addresses all the capabilities of the 1600GTO, and adds
enhancements not currently available in the keypad or in any other software.
The 1600 is equally at home in a permanent observatory or as a portable mounting for remote star parties thanks to the
ease with which the two axes come apart. This is the perfect
mount for a large refractor, Newtonian, Cassegrain or
astrograph.
In order to maximize your pleasure on your rst night out, we
recommend that you familiarize yourself with the assembly
and basic operation of the mount indoors. The temperature
will be comfortable, the mosquitoes at bay, and you’ll have
enough light to see the illustrations and read the manual.
Please take particular note of counterbalancing, use of the
clutches and operation of the keypad controller.
Why Polar Alignment is Important
Polar alignment permits accurate R.A. movement in order to
compensate for the Earth’s rotation.
If you were to take a long exposure photograph with Polaris
(often called the north star) in the center of the eld, you
would discover that all stars seem to revolve around
Polaris. This effect is due to the rotation of the earth on
its axis. Motor-driven equatorial mounts were designed to
compensate for the earth’s rotation by moving the telescope
at the same rate and opposite to the earth’s rotation. When
the polar axis of the telescope is pointed at the celestial pole
(polar aligned) as shown in the diagram at right, the mount
will follow (track) the motions of the sun, moon, planets and
stars. As a result, the object that you are observing will
appear motionless as you observe through the eyepiece or
take astrophotos.
Equator
South North
Direction of
the Celestial
North Pole
Earth
Direction of
the Celestial
North Pole
Direction of
the Polar Axis
Horizon
Zenith
Earth’s Axis
L
a
t
i
t
u
d
e
L
a
t
i
t
u
d
e
Northern
Hemisphere
Earth’s Rotation
Mount’s
Counter-rotation
7
ASSEMBLY DIAGRAM
The following terms and abbreviations are used interchangeably in these instructions:
Polar axis = right ascension axis = R.A. axis = R.A. housing
Declination axis = Dec. axis = Dec. housing
Please read all instructions before attempting to set up your 1600GTO mount. The model 1600GTO is very rugged;
however, like any precision instrument, it can be damaged by improper handling. Please refer to the diagram below
for an illustration of the mount. The parts are labelled so that we can establish common terminology. Pay particular
attention to the section regarding joining and separating the R.A. and Dec. axes as this is unique to this mount. It is
important to note the need to connect and disconnect the Dec. Servo Cable internally.
Declination
Motor/Gearbox
R.A. Motor/
Gearbox
Counterweight
Shaft
GTOCP4
Control
Box
Azimuth Adjuster
Polar Axis
Pivot Bolt
Altitude
Adjuster Knob
Polar Axis
Lock Knobs (4)
Dec. Sight Hole
Cover
Clutch Knobs
(3 each axis)
Dec. Top Plate
Lock Knobs (2)
Cable
Channel (2)
Encoder
Connector
GTOCP4
Cable
Cable Access
Cover
Dec. Lock
Knobs (2)
Declination
Counterweight
Adapter Encoder
Cover
Plates
R.A. Sight
Hole Cover
R.A. / Dec.
Cable Covers
Declination
Axis Housing
Safety Stop
R.A. Axis
Housing
Polar Fork
Assembly
Dec. Top Plate
Safety
Screw (4)
Safety
Screw (2)
Dec. Cable
Covers
8
PLAN AHEAD AT HOME
Handy Tools to Have on Hand
In Your Accessory or Tool Box:
● Small torpedo level to level your scope when using the handy reference park positions, particularly during the daytime
polar alignment routine outlined in your Keypad manual.
● Compass - Don’t forget to know your magnetic offset when using a compass (there can be a large difference).
On Your Smart Phone:
For the upmost of convenience, the following items can be downloaded to your smart phone, which you are likely carry with
you everywhere.
● App(s) that allow your phone to be used as a level, inclinometer and compass. Don’t forget to know your magnetic
offset when using a compass since there can be a large difference.
● Astro-Physics Polar Alignment app – The longitude and latitude of your current site will display. Apps are available for
iOS, Android and Windows.
Quick Start Summary – New Installations
This summary gives an outline of the workow to have a successful rst observing session. Enjoy!
1. Install and set up your control software and drivers. For all but the AP GTO Keypad, this can be done before you even
take delivery of your mount.
a) Set up ASCOM and the drivers rst
i) ASCOM Platform 6.3 (currently) - ascom-standards.org
ii) AP V2 ASCOM driver - http://www.gralak.com/apdriver
iii) FTDI driver - http://www.ftdichip.com/Drivers/VCP.htm See location of driver:
http://www.astro-physics.com/products/accessories/software/Serial_USB/FTDI_driver_nd4.pdf
b) Install third party software (Starry Night, TheSkyX, MaxImDL, etc.)
c) Adjust software settings - follow the appropriate Workow documentation that follows in this guide
d) If using the Keypad along with a computer, set the Keypad to AutoConnect=EXT and power cycle the mount in
order to lock in the change.
2. Assemble the mount.
3. Balance the system.
4. Polar align the mount – at least roughly. (If using the daytime routine, move this step to after the mount is initialized. If
using the RAPAS, do it before initializing.)
5. Place the system into a pre-dened AP Park position for initialization.
6. Power up the mount and connect with your primary control software. Use the primary control software to initialize
the mount. Start out from the park position chosen in #5 above. Your other initialization settings will have been set
already in step #1.
a) If using APCC, always start it and connect with it rst.
b) If the AP V2 Driver is your primary control software, it must be started with a client program.
7. Connect other software that you will use with the mount.
8. After nishing your night’s observing (or day’s solar observing) it is best to park the mount into your chosen Park posi-
tion using either the AP V2 driver or APCC, rather than Third Party software if you are using a PC for mount control.
9. Power down the mount.
9
AT YOUR OBSERVING SITE
Assemble Pier (purchased separately)
Begin by assembling the portable pier at the desired observing
location. Take note which direction is north. (These instructions
are for the Astro-Physics Portable Piers. For other piers, please
follow the manufacturer’s instructions.)
1. Slide the three legs onto the nubs of the base and rotate
the assembly so that one of the legs points toward north (or
toward the south if in the southern hemisphere).
2. Place the pier post on the base, orienting the eyelets for at-
taching the turnbuckles directly above each leg.
3. Attach the tension rods. The turnbuckles should be drawn
tight until the whole assembly is stiff enough to support your
weight without movement.
Attach Polar Axis Assembly to Pier
In order to track the motion of astronomical objects, the Polar Axis must be positioned so that an imaginary line drawn
through the center of the axis points toward the celestial pole. Refer to the diagram at the front of this manual for a
graphical representation. At this stage of the assembly process, you want to position the pier so that it points roughly
north.
1. Prior to mounting the Polar Axis. Adjust the Azimuth Ad-
juster so that the Azimuth Adjuster Block is centered. This will
allow adjustability when it comes time to polar align the mount.
2. Orient the pier. Set up your pier so that the counterweight
shaft is oriented above the north pier leg. It is important when
using a portable pier to face one leg to the north so that the
offset weight of the counterweight shaft and counterweights do
not create an unstable balance.
3. Set the R.A. Axis in place. Carefully set the 1600GTO Right Ascension Axis / Polar Fork assembly into the open top
of your pier, or into the 1600 Flat Surface Adapter (1612FSA), if you are using one. Unless you are quite strong, it is
ideal to have two people involved in the operation of lifting and stabilizing the assembly as it is positioned into the pier
or 1612FSA.
4. Line up the Pier base. If the side thru-holes in the pier or 1612FSA are not perfectly lined up with the tapped holes
in the mount’s Pier Adapter base, rotate the mount, noting that the azimuth adjuster knobs should be locked to the
adjuster block. Otherwise, the base will rotate making it difcult to line up the holes.
5. Secure the R.A. Axis to the pier. When you have the holes lined up, fasten the mount to the pier top or to the Flat
Surface Adapter using six 5/16-18 X 5/8” socket button head cap screws and 5/16 at washers. Note that the washers
have a sharp edged side and a softly rounded side. Be sure that the rounded side faces the paint or anodizing of the
pier so that no marring of the nish occurs. Be sure to start all six cap screws (with their washers) before tightening
any of them. Then, snug all six cap screws down before nally tightening them all securely.
6. Level the mount. Although it is not important that a German equatorial mount be level to achieve polar alignment,
it does make it easier in that an adjustment to altitude or azimuth affects only the direction to which you are making
the adjustment. If the mount is not level, you will be able to achieve alignment, but when you make an adjustment to
azimuth, for example, you are actually making an adjustment to both directions when out of level. Note that if you are
using the Right-Angle Polar Scope, it is required to be level in the east-west direction in order to achieve accurate polar
alignment. Level the mount...you’ll be ahead in the game!
Special note: It is a very good idea to include a small torpedo level and a compass in your accessory carry box,
along with your other tools, when setting up portably. Modern cell phones, such as the iPhone, have Apps
available that allow the phone to be used as a level, an inclinometer and a compass.
Azimuth Adjuster
(underside view)
Azimuth Adjuster Block
Azimuth Threaded Push Rod
Indice
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