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Orion - SkyQuest XX12g GoTo Truss Tube Dobsonian


Discontinued Product

Manufactured by: Orion


This is a discontinued item. We recommend the newer version of the Orion SkyQuest XX12g GoTo Truss Tube Dobsonian Telescope as a replacement.

Orion SkyQuest XX12g GoTo Truss Tube Dobsonian

Orion's latest innovative combination of big-aperture performance and convenient portability comes to life in the form of the Orion SkyQuest XX12g GoTo Truss Tube Dobsonian telescope. Our most advanced 12-inch Dobsonian is geared up for extensive exploration of the night sky, with fully motorized GoTo and tracking drives providing automated pointing to any of the over 42,000 celestial objects in the hand controller's database.

  • 12-inch aperture Truss Tube Dobsonian telescope with fully motorized GoTo and tracking functionality
  • Orion-designed collapsible Dobsonian base and optical tube break-down into smaller components for easy transport and storage
  • Rigid 8-pole truss tube design eliminates flexure observed in 6- and 3-pole Dobsonians
  • Automatically locates and then tracks any of over 42,000 celestial objects in the GoTo controller's database
  • Optical encoders, drive motors, and gears come pre-installed on base, making assembly a snap


Orion designed the XX12g's optical tube and base with portability in mind. The truss tube can be divided into a small front tube section including the secondary mirror and focuser, rear tube section housing the primary mirror cell, and the four truss-pole pairs. We've increased the portability of the XX12g compared to its XX12i IntelliScope-equipped counterpart by making the base collapsible for easy no-tools-required disassembly into four separate, smaller pieces for easier transport. The separated component pieces of the XX12g tube and base can be stored without taking up an excessive amount of space in your home, and can be transported in virtually any standard-sized car to your favorite dark-sky observing site.

The XX12g telescope optical tube employs a rigid 8-pole truss design that virtually eliminates flexure observed in 6- and 3-pole collapsible tube designs. Stability of the assembled XX12g Dobsonian base is enhanced by its 1-inch thick composite wood base panels, which are laminated with water-resistant black melamine. GoTo and tracking motors are pre-installed on the base panels, making assembly nice and easy. Once the tube and base are assembled, the optical tube attaches to the base with a dovetail trunnion and locks securely in place with a single captive hand knob.

The XX12g GoTo system automatically slews the telescope to any of the over 42,000 celestial objects you choose from the hand controller's intuitive menus, once a simple alignment process is completed. Altitude and azimuth motors automatically track the motion of the target object so it stays put in the eyepiece field of view for extended visual study. For anyone who has spent an evening manually tracking objects with a Dobsonian this is a profound upgrade, and trust us, it was worth the wait. Forgiving of bumps and nudges, the XX12g features closed-loop electronics allowing manual repositioning, or slewing, of the telescope tube without losing alignment of the GoTo system.

With 12 inches (305mm) of light gobbling aperture and a fast f/4.9 focal ratio, the XX12g is capable of providing clear, crisp and very bright views of the night sky in a 2-inch or 1.25-inch eyepiece installed in its 2-inch dual-speed Crayford focuser with 1.25-inch adapter. The 12-inch diffraction-limited parabolic primary mirror is crafted from low thermal expansion glass for speedy ambient temperature acclimation and optimal visual performance. The included cooling accelerator fan helps hasten temperature acclimation of the primary mirror (requires 8 D-cell batteries, or other 12V power source, not included). The primary mirror features enhanced reflectivity aluminum coatings which provide 94% reflectivity and a protective quartz overcoat, so you get the most out of each and every photon collected.

The XX12g is outfitted with a thorough set of included accessories. A 35mm DeepView 2-inch eyepiece provides wide 56-degree views and a 12.5mm illuminated Plossl 1.25-inch eyepiece helps optimize GoTo system alignment. A collimation cap, removable eyepiece rack, 12V DC power cable and RS-232 cable are also included. A 12V power supply (sold separately) is required for use of the GoTo system and motors.

In keeping with Orion's tradition of offering top-notch quality optics at affordable prices the XX12g GoTo Truss Tube Dob is priced to please. Includes a FREE Starry Night Special Edition software CD-ROM and SkyTheater DVD - a $69.90 value! As with all Orion telescopes, our Customer Service and Technical Support teams are available to help with any questions you may have on our exciting new 12-inch GoTo Truss Tube Dobsonian.

A specially designed Light Shroud is available (sold separately) for the Orion XX12g optical tube. A Light Shroud significantly enhances the viewing experience in a Truss Tube Dobsonian by blocking distracting peripheral light from entering the light path, optimizing contrast and brightness.

A custom Orion Padded Case Set (sold separately) is available for the XX12g Dobsonian optical tube. Each set of cases includes a padded case for the top tube section including a secondary mirror cover, a padded case for the bottom tube section, and a roll-up case to safely hold the truss-pole assemblies. An Orion Padded Case Set is the best way to preserve and protect your investment for years to come.

With the Orion SkyQuest XX12g GoTo Truss Tube Dobsonian telescope, you're amply equipped for big-aperture visual adventures, wherever you may roam.

Assembled weight (including accessories): 118 lbs. Assembled optical tube, 56"L x 14"W, 49.5 lbs. Bottom tube section, 26"L x 14"W, 34.3 lbs; top tube section, 8"L x 14"W, 9.6 lbs. Truss pole assemblies (4), 24"L x 4.6"W x 1.75"H. Total weight of 4 truss pole assemblies: 5.6 lbs. Base, 28"W x 33.5"H, 71 lbs. 12V battery pack included (requires 8 D-cells: not included) to power Cooling Accelerator Fan. One-year limited warranty.

Updating the GoTo Hand Controller's Firmware
From version 3.0 and up, the computerized GoTo hand controller's firmware can be updated over the internet.


System Requirements

  • GoTo hand controller version 3.0 or greater

  • Windows95 or later

  • An available RS-232 COM port on the PC

  • Computer interface cable (supplied)

  • DC power supply (7.5V to 15V @ 100mA or greater output with 2.1mm tip positive plug)


Preparing the Computer for the Update

  1. Create a folder where you will store the files necessary for the update.

  2. Click on the Download Firmware Loader link below and save the file to the folder you have created on your computer. You will need to download this program only once; after it is saved on your computer, only the firmware data file is needed for future updates.

  3. Click the Download Firmware File link and save the data file to the folder you created. The file will be named OrionVxxxxEQ.ssf, where xxxx indicates the version number of the firmware.


Updating the GoTo Hand Controller

  1. Plug the modular plug end of the computer interface cable into the middle jack in the hand controller. Plug the serial connector end of the cable to the COM port on your PC.

  2. Press and hold down the 0 and 8 numerical buttons simultaneously, then plug the power supply into the hand controller's DC power jack. The hand controller will beep and display "SynScan Update Ver. x.x" on the LCD screen.

  3. Run the Firmware Loader program on your computer.

  4. Click on the "Browse" box and select the OrionVxxxx.ssf file location where it was saved previously on your computer.

  5. Click on the "Update" button, and the new firmware will begin loading into the hand controller. The Firmware Loader will show the progress of the update on your computer screen. It will usually take approximately 5 minutes for the new firmware to load into the hand controller. It may take significantly longer if a serial-to-USB adapter is employed on your computer.

  6. When the download is complete, the Firmware Loader will display "Update Complete".


The firmware in the GoTo hand controller has now been updated. You can click on the "HC. Version" button to confirm the new version number of the firmware (and possibly the database, but the hardware version will not change with internet updates).

Note: If the error message "Can not connect to a SynScan hand control" appears on your computer, check all cable connections. Also, try closing all other computer programs that might be attempting to use the COM port.

Note: If the error message "Firmware update failed..." appears on your computer, remove the power plug from the hand controller, and then reconnect it. Now, repeat the firmware update procedure.

By default, the data communication rate between the GoTo hand controller and the computer is 115kbps. The RS-232 port on some PCs may not support this high data transfer rate. If the firmware update procedure fails after a few tries, try reducing the data transfer rate by pressing the SETUP button on the hand controller. This will reduce the data transfer rate to 9.6kbps. The controller's LCD screen will show "Lo" in the lower right hand corner to indicate the lower transfer rate setting. The firmware update procedure remains the same except it will take much longer for the firmware to load into the hand controller.





Additional Information

Name Orion - SkyQuest XX12g GoTo Truss Tube Dobsonian
Manufacturer Orion
Model 10137
Discountinued Yes
Alignment Procedures 2-Star Alignment
Bearings AZ: Thrust needle bearings ALT: Ball bearings
Diameter 305mm
Eyepieces DeepView 35.0mm (2"), Plossl 12.5mm (1.25")
Finderscope EZ Finder II
Focal Length 1500mm
Focal Ratio f/4.9
Focuser 2" dual-speed Crayford
Highest Useful Magnification 300x
Included Accessories Cooling accelerator fan included, 2" Dual-speed Crayford focuser w/ 1.25" adapter
Limiting Stellar Magnitude 15.1
Lowest Useful Magnification 42x
Magnification 42x, 120x with eyepieces
Optical Design Reflector
Optical Tube Steel
Optical Tube Length 58.3 in
Power Requirements 12-volt DC (tip positive)
Secondary Mirror Obstruction 70mm
Secondary Mirror Obstruction by Area 5%
Secondary Mirror Obstruction by Diameter 23%
Tripod Wood