Figure 1.5. Thread the collimation thumbnuts, with nylon washers attached, through the rear end ring and onto the threaded shafts. Make sure the thumbnuts have at least three full turns of engagement on the shafts.
Next, assemble the rear end ring to the mirror cell. Find a clean, flat surface, and turn the mirror cell over so that the mirror is facing downwards. Place the three springs onto the three exposed threaded shafts (Figure 1.3). Lower the end ring onto the mirror cell so the threaded shafts pass through it, and the end ring rests on the springs (Figure 1.4). Add a nylon washer to each collimation knob and thread the col- limation knobs through the end ring and onto the threaded shafts (Figure 1.5). Make sure the knobs have at least three full turns of engagement on the shafts. The mirror cell is now ready to be installed into the tube.
Assembling the SkyQuest XT12i IntelliScope mirror cell to the tube can be a bit tricky. This is because the large diameter and thin aluminum of the tube will cause the tube to become somewhat out of round once the rear end ring is removed.
To assemble the mirror cell to the tube, stand the tube up vertically so that the raw edge of the tube is facing upward. Line up the threaded holes in the edge of the mirror cell end ring with the holes in the end of the tube. Then, lower the mirror cell onto the tube so that one side of the end ring is fully seated onto the tube (Figure 1.6). Now, look along the perimeter of the tube, and you will notice a bulge in the tube that prevents the mirror cell from fully seating on the tube (Figure 1.7). Position your body so that your chest is pressing against this bulge, and hug the telescope with your left hand so that the tube becomes round. With your right hand, gently tap down the side of the mirror cell that needs to be seated, and the entire mirror cell should seat onto the tube (Figure 1.8). Then replace the
Figure 1.6. Lower the assembled mirror cell onto the tube so one side of the end ring is seated on the tube edge. The threaded attachment holes in the end ring should also be lined up with the through holes in the end of the tube.
Figure 1.7. Locate the area of tube that is bulging out and preventing the mirror cell from fully seating.
Figure 1.8. Hug the tube so that your chest pushes against the bulge, and a gentle tap should fully seat the mirror cell onto the tube.
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