INSTRUCTION MANUAL Orion EQ-1 Equatorial Mount ® #9011 Customer Support (800) 676-1343 E-mail: support@telescope.com Corporate Offices (831) 763-7000 Providing Exceptional Consumer Optical Products Since 1975 P.O. Box 1815, Santa Cruz, CA 95061 IN 146 Rev. A 0500 Mounting platform R.A. lock thumb screw Dec. lock thumb screw (not shown) R.A. slow-motion control Dec. slow-motion control Counterweight lock knob Counterweight Counterweight shaft Tripod leg attachment bolt Latitude adjustment t-bolt Azimuth lock knob Latitude lock t-bolt Accessory tray bracket Accessory tray Leg lock knob Figure 1. EQ-1 Equatorial Mount parts diagram 2 Congratulations on your purchase of a quality Orion product. Your new EQ-1 Equatorial Mount was designed to work with many different telescope optical tubes. With its precision equatorial head, you'll be able to easily track astronomical objects over time so that they remain within your eyepiece's field of view. The setting circles will help locate hundreds of fascinating celestial denizens, including galaxies, nebulas, and star clusters. With a little practice and a little patience, you'll find that your EQ-1 Equatorial Mount is an invaluable tool for getting the most out of your astronomical observing sessions. These instructions will help you set up and properly use your equatorial mount. Please read them over thoroughly before getting started. Table of Contents 1. Parts List................................................................................................................................ 3 2. Assembly ............................................................................................................................... 3 3. Attaching A Telescope ........................................................................................................... 4 4. Balancing the Telescope........................................................................................................ 5 5. Setting Up and Using the Equatorial Mount.......................................................................... 6 6. Specifications....................................................................................................................... 10 7. Suggested Accessories ....................................................................................................... 10 1. Parts List Qty. Description 1 1 2 1 1 3 3 3 1 3 1 German-type equatorial mount Latitude adjustment t-bolt Slow-motion control cables Counterweight Counterweight shaft Tripod legs Tripod leg attachment bolts with wing nuts and washers Leg lock knobs Accessory tray Accessory tray screws with wing nuts and washers Assembly tool Assembling the mount for the first time should take about 30 minutes. No tools are needed, other than the one provided. All bolts should be tightened securely to eliminate flexing and wobbling, but be careful not to over-tighten or the threads may strip. Refer to Figure 1 during the assembly process. 1. Lay the equatorial mount on its side. Attach the tripod legs, one at a time, to the base of the mount by sliding a tripod leg attachment bolt through the top of a leg and through the holes in the base of the mount. The washers should be on the outside of the tripod legs. Secure the wing nuts finger-tight. Note that the hinged accessory tray bracket on each leg should face inward. 2. Attach and tighten the leg lock knobs at the base of the tripod legs. For now, keep the legs at their shortest (fully retracted) length; you can extend them to a more desirable length later, after the mount is completely assembled. 3. With the tripod legs now attached to the equatorial mount, stand the tripod upright (be careful!) and spread the legs apart enough to attach the accessory tray to the three hinged tray brackets on the legs. The slots in the brackets should be positioned underneath the holes in the three corners of the tray. Use the three small accessory tray screws and wing nuts provided to fasten the tray to the brackets. Do not tighten the wing nuts yet. 2. Assembly Carefully open all of the boxes in the shipping container. Make sure all the parts listed in Section 1 are present. Save the original boxes and packaging material. In the unlikely event that you need to return the telescope, you must use the original packaging.Note: The EQ-1 Equatorial Mount is packaged with one empty interior box; the box is included for structural integrity only. 3 4. With the accessory tray attached loosely, spread the tripod legs apart as far as they will go, until the accessory tray brackets are taut. Then tighten the wing nuts. 5. Next, tighten the wing nuts on the tripod leg attachment bolts at the base of the equatorial mount, so that the legs are securely fastened. You can use the provided assembly tool to hold the heads of the bolts while firmly tightening the wing nuts. 6. Thread the latitude adjustment t-bolt into the hole in the rear of the equatorial mount (see Figure 2). Orient the mount as it appears in Figure 2, at a latitude of about 40°, i.e., so that the pointer next to the latitude scale is pointing to the hash mark at "40." To do this, loosen the latitude lock t-bolt (central to the latitude scale), and turn the latitude adjustment tbolt until the pointer and the "40" line up. Then re-tighten the latitude lock t-bolt. You may also need to rotate the mount about its right ascension (R.A.) and declination (Dec.) axes (see Figure 2). Do this by first loosening the R.A. and Dec. lock thumb screws. 7. Slide the counterweight onto the counterweight shaft. Make sure the counterweight lock knob is adequately loosened so the counterweight shaft can pass through the hole in the counterweight. 8. With the counterweight lock knob still loose, grip the counterweight with one hand and thread the shaft into the equatorial mount (at the base of the declination axis) with the other hand. When it is threaded as far in as it will go, position the counterweight about halfway up the shaft and tighten the counterweight lock knob. The washer and screw on the end of the counterweight shaft will prevent the counterweight from slipping off the shaft and possibly onto your foot if the counterweight lock knob should come loose 9. Now attach the two slow-motion cables to the R.A. and Dec. slow-motion shafts (see Figure 2) of the equatorial mount by positioning the thumb screw on the end of the cable over the indented slot on the shaft, then tightening the thumb screw. A cable can be attached to either end of the R.A. shaft, whichever is most convenient for you. Use the shorter cable for the R.A. shaft. 3. Attaching a Telescope The EQ-1 Equatorial Mount is designed to hold small to mid-size telescopes weighing up to about 7 lbs. For heavier telescopes, the mount may not provide sufficient stability for steady imaging. Any type of telescope can be mounted on the EQ-1 Equatorial Mount, including refractors, Newtonian reflectors, and cadadioptrics, provided a proper adapter or set of tube rings is available to couple the tube to the mount. Orion carries a variety of differently sized tube rings and a 1/4"-20 mounting adapter designed exclusively for the EQ-1 Equatorial Mount. One of these items probably fits the telescope tube you wish to mount. See the list of Suggested Accessories at the end of these instructions, or check the Orion print or online catalogs for currently available mounting accessories. The Declination (Dec.) slowmotion shaft N IO NS CE AS IS AX Declination (Dec.) setting circle XIS NA TIO INA CL DE R.A. lock knob T GH RI Right ascension (R.A.) setting circle Right ascension (R.A.) slow-motion shaft Latitude scale Latitude locking t-bolt Latitude adjustment t-bolt Figure 2. The equatorial mount 4 mounting accessories fasten to the two holes in the top platform of the equatorial mount. 4. Balancing the Telescope Once the telescope is attached to the equatorial mount, the next step is to balance the telescope. Proper balance is required to insure smooth movement of the telescope on both axes of the equatorial mount. If you attach your telescope with a 1/4"-20 adapter, it may not be possible to balance the scope precisely with respect to the declination axis, because the telescope cannot be moved back and forth as it can when tube rings are used. Assuming you will be using tube rings, we will first balance the telescope with respect to the R.A. axis, then the Dec. axis. 1. Keeping one hand on the telescope optical tube, loosen the R.A. lock thumb screw. Make sure the Dec. lock thumb screw is locked, for now. The telescope should now be able to rotate freely about the R.A. axis. Rotate it until the counterweight shaft is parallel to the ground (i.e., horizontal). 2. Now loosen the counterweight lock knob and slide the weight along the shaft until it exactly counterbalances the telescope (Figure 3a). That's the point at which the shaft remains horizontal even when you let go of the telescope with both hands (Figure 3b). Retighten the counterweight lock knob. The telescope is now balanced on the R.A. axis. 3. To balance the telescope on the Dec. axis (this is not possible if using a 1/4"-20 mounting adapter), first tighten the R.A. lock thumb screw, with the counterweight shaft still in the horizontal position. 4. With one hand on the telescope optical tube, loosen the Dec. lock thumb screw (Figure 3c). The telescope should now be able to rotate freely about the Dec. axis. Figure 3b. Telescope is now balanced on the R.A. axis. That is, when hands are released, counterweight shaft remains horizontal. Figure 3a. Balancing the telescope with respect to the R.A. axis by sliding the counterweight along its shaft. Figure 3c. Preparing the telescope to be balanced on the Dec. axis by first releasing the Dec. lock knob. 5 Loosen the tube ring clamps a few turns until you can slide the telescope tube forward and back inside the rings (this can be aided by using a slight twisting motion on the optical tube while you push or pull on it) (Figure 3d). Position the telescope so that it remains horizontal when you carefully let go with both hands. This is the balance point for the Dec. axis (Figure 3e). Before clamping the rings tight again, rotate the telescope so that the eyepiece is at a convenient angle for viewing. 5. Setting Up and Using the Equatorial Mount When you look at the night sky, you no doubt have noticed that the stars appear to move slowly from east to west over time. That apparent motion is caused by the Earth's rotation (from west to east). An equatorial mount (Figure 2) is designed to compensate for that motion, allowing you to easily "track" the movement of astronomical objects, thereby keeping them from drifting out of the telescope's field of view while you're observing. This is accomplished by slowly rotating the telescope on its right ascension (polar) axis, using only the R.A. slow-motion cable. But first the R.A. axis of the mount must be aligned with the Earth's rotational (polar) axis; this is a process called polar alignment. Polar Alignment For Northern Hemisphere observers, approximate polar alignment is achieved by pointing the mount's R.A. axis at the North Star, or Polaris. It lies within 1° of the north celestial pole (NCP), which is an extension of the Earth's rotational axis out into space. Stars in the Northern Hemisphere appear to revolve around Polaris. Figure 3d. Balancing the telescope with respect to the Dec. axis. As shown here, the telescope is out of balance (tilting). To find Polaris in the sky, look north and locate the pattern of the Big Dipper (Figure 4). The two stars at the end of the "bowl" of the Big Dipper point right to Polaris. Observers in the Southern Hemisphere aren't so fortunate to have a bright star so near the south celestial pole (SCP). The star Sigma Octantis lies about 1° from the SCP, but it is barely visible with the naked eye (magnitude 5.5). For general visual observation, an approximate polar alignment is sufficient: 1. Level the equatorial mount by adjusting the length of the three tripod legs. 2. Loosen the latitude lock t-bolt. Turn the latitude adjustment t-bolt and tilt the mount until the pointer on the latitude scale is set at the latitude of your observing site. If you don't know your latitude, consult a geographical atlas to find it. For example, if your latitude is 35° North, set the pointer to +35. Then retighten the latitude lock t-bolt. The latitude setting should not have to be adjusted again unless you move to a different viewing location some distance away. 3. Loosen the Dec. lock thumb screw and rotate the telescope optical tube until it is parallel with the R.A. axis. The pointer on the Dec. setting circle should read 90°. Retighten the Dec. lock thumb screw. Figure 3e. Telescope is now balanced on the Dec. axis, i.e., it remains horizontal when hands are released. The telescope is now balanced on both axes. Now when ...