Figure 24. Rather than assembling the entire optical tube and then hoisting it onto the base, some may find it more convenient to mount the lower tube section on the base first, then install the truss tubes and upper tube section.
Note: If desired, you can mount the lower tube section on the base before connecting the truss pole assemblies and upper tube section (Figure 24). You may find it easier to lift the lower tube section and guide it onto its resting place on the base’s bearing cylinders than hoisting and mounting the fully assem- bled optical tube.
8.Connect the upper tube section to the four truss connec- tors at the top of the poles. Orient the upper tube section as shown in Figure 25. Hold the upper tube section with one hand while threading the knobs in the truss connec- tors into the holes in the upper truss support ring. If nec- essary, you can slightly adjust the position of the truss connector with respect to the pole ends in order to have the knobs and holes line up (Figure 26). When tightened, the knob will clamp the truss connector against the regis- tration flats on the upper truss support ring (Figure 27). Repeat this for the other three truss connectors. Firmly tighten the knobs.
Figure 25. When the optical tube is assembled, the upper tube section should be oriented relative to the lower tube section as shown. Note the orientation of the focuser on the upper tube section relative to the side bearing on the lower tube section.
Truss | Button head cap screw | |
connector |
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Truss poles
a. | b. |
Figure 26. The position of the truss connectors relative to the pole ends can be adjusted to register the truss connectors with the upper truss support ring.
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