Celestron Advanced VX 9.25 Schmidt-Cassegrain Telescope Advanced VX Manual - Page 10

Balancing the Mount in R.A. To eliminate undue stress on the mount, the telescope should be properly balanced around the polar axis. Proper balancing is crucial for accurate tracking. To balance the mount: 1. V erify that the telescope is securely attached to the telescope mounting platform. 2. L oosen the R.A. lock lever and position the telescope off to one side of the mount. The counterweight bar will extend horizontally on the opposite side of the mount. 3. R elease the telescope - GRADUALLY - to see which way the telescope "rolls." 4. L oosen the set screws on the side of the counterweight, so it can be moved the length of the counterweight bar. 5. Move the counterweight to a point where it balances the telescope (i.e., the telescope remains stationary when the R.A. clutch knobs are loose). 6. Tighten the screw on the counterweight to hold it in place. 3. Loosen the DEC clutch lock lever and rotate the telescope until the tube is parallel to the ground. 4. Release the tube - GRADUALLY - to see which way it rotates around the declination axis. DO NOT LET GO OF THE TELESCOPE TUBE COMPLETELY! 5. Slightly loosen the knobs that hold the telescope to the mounting platform and slide the telescope either forward or backward until it remains stationary when the DEC clutch is loose. Do NOT let go of the telescope tube while the knob on the mounting platform is loose. It may be necessary to rotate the telescope so that the counterweight bar is pointing down before loosening the mounting platform screw. 6. Tighten the knobs on the telescope mounting platform to hold the telescope in place. Like R.A. balance, these are general balance instructions and will reduce undue stress on the mount. When taking astroimages, this balance process should be done for the specific area at which the telescope is pointing. Adjusting the Mount In order for a motor drive to track accurately, the telescope's axis of rotation must be parallel to the Earth's axis of rotation, a process known as polar alignment. Polar alignment is achieved NOT by moving the telescope in R.A. or DEC but by adjusting the mount vertically, which is called altitude and horizontally, which is called azimuth. This section simply covers the correct movement of the telescope during the polar alignment process. The actual process of polar alignment, or making the telescope's axis of rotation parallel to the Earth's, is described later in this manual in the section on "Polar Alignment." Tip: While the above instructions describe a perfect balance arrangement, there should be a SLIGHT imbalance to ensure the best possible tracking. When the scope is on the west side of the mount the counterweight should be slightly imbalanced to the counterweight bar side. And when the tube is on the east side of the mount there should be a slight imbalance toward the telescope side. This is done so that the worm gear is pushing against a slight load. The amount of the imbalance is very slight. When taking astroimages, this balance process can be done for the specific area at which the telescope is pointing to further optimize tracking accuracy. Adjusting the Mount in Altitude • To increase the latitude of the polar axis, tighten the rear latitude adjustment screw and loosen the front screw. • To decrease the latitude of the polar axis, tighten the front latitude adjustment screw (located below the counterweight bar and loosen the rear screw. The latitude adjustment on the Advanced VX mount has a range from approximately 7° to 77°. Balancing the Mount in DEC Although the mount does not track in declination, the telescope should also be balanced in this axis to prevent any sudden motions when the DEC lock lever is loose. To balance the telescope in DEC: 1. Loosen the R.A. clutch lock lever and rotate the telescope so that it is on one side of the mount (i.e., as described in the previous section on "Balancing the Mount in R.A."). 2. Tighten the R.A. lock lever to hold the telescope in place. Azimuth Adjustment Knobs Latitude Adjustment Knobs 10 I