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Collimation (Alignment) of the Optics
All Meade 114ST EQ-D telescopes are optically aligned at the factory prior to shipment. It is unlikely that you will need to align, or collimate, the optics after receipt of the instrument. However, if the telescope received unusually rough handling in shipment, it is possible that the optics must be re aligned for best optical performance. In any case this alignment procedure is simple, and requires only a few minutes the very first time the telescope is used. Take the time to familiarize yourself with the following collimation procedure, so that you will recognize a properly collimated instrument and can adjust the collimation yourself, if necessary.
a. Correct collimation
The properly collimated (aligned) mirror system in the Meade 114ST EQ-D assures the sharpest images possible. This occurs when the primary mirror and diagonal mirror are tilted so that the focused image (see Fig. 6) falls directly through the center of the focuser drawtube (17, Fig. 1a). These mirror tilt adjustments are made with the diagonal assembly (Fig. 7) and the primary mirror cell (Fig. 8), and will be discussed later.
To inspect the view of the mirror collimation, look down the focuser drawtube with the eyepiece removed. The edge of the focuser drawtube (1, Fig. 9), will frame the reflections of the primary mirror with the 3 mirror clips (2, Fig. 9), the diagonal mirror (3, Fig. 9) , the spider vanes (4, Fig. 9), and your eye (5, Fig. 9). Properly aligned, all of these reflections will appear concentric (i.e., centered) as illustrated in Fig. 9.
Any deviation from the concentric reflections will require adjustments to the diagonal assembly (Fig. 7), and/or the primary mirror cell (Fig. 8).
b. Diagonal holder adjustments
If the diagonal mirror (1, Fig. 10) is centered in the drawtube (2, Fig. 10), but the primary mirror is only partially visible in the reflection (3, Fig. 10), the 3 Phillips-head diagonal tilt screws (1, Fig. 7). Note: To adjust these screws you must first remove an adhesive backing) must be unthreaded slightly to the point of where you can tilt the diagonal holder (3, Fig. 7) from side-to-side by grasping the diagonal holder with your hand and tilt until you see the primary mirror become as centered in the reflection of the diagonal mirror as possible. Once you are at the best position, thread in the 3 Phillips-head diagonal tilt screws to lock the rotational position. Then, if necessary, make adjustments to these 3 Phillips-head screws to refine the tilt-angle of the diagonal mirror until the entire primary mirror can be seen centered within the diagonal mirror reflection. When the diagonal mirror is correctly aligned, it will look like Fig. 10. (Note: The primary mirror is shown out of alignment.)
c. Primary mirror adjustments
If the diagonal mirror (1, Fig. 11) and the reflection of the primary mirror (2, Fig. 11) appear centered within the drawtube (3, Fig. 11), but the reflection of your eye and the reflection of the diagonal mirror (4, Fig. 11) appear off-center, you will need to adjust the primary mirror tilt Phillips-head screws of the primary mirror cell (3, Fig. 11). These primary tilt screws are located behind the primary mirror, at the lower end of the main tube. See Fig. 6. To adjust the primary mirror tilt screws, first unscrew several turns, the 3 hex-head primary mirror cell locking screws (2, Fig. 8) that are next to each primary mirror tilt Phillips-head screw. Then by trial-and-error, turn the primary mirror tilt Phillips-head screws (3, Fig. 8) until you develop a feel for which way to turn each screw to center the reflection of your eye. Once centered, as in Fig. 9, turn the 3 hex-head primary mirror cell locking screws (2, Fig. 8) to relock the tilt-angle adjustment.
Diagonal | Diagonal Mirror | Primary Mirror |
Assembly |
| | Primary Mirror-Tilt |
| Focused Image | Screws |
| |
