Meade Instruments 4500 - Manual (Page 12)

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H. Maintenance
1. Cleaning
As with any quality instrument, lens or mirror surfaces should be cleaned as infrequently as possible. Front
surface aluminized mirrors, in particular, should be cleaned only when absolutely necessary. In all cases
avoid touching any mirror surface. A little dust on the surface of a mirror or lens causes negligible loss of
performance and should not be considered reason to clean the surface. When lens or mirror cleaning does
become necessary, use a camel’s hair brush or compressed air gently to remove dust. If the telescope’s dust
cover is replaced after each observing session, cleaning of the optics will rarely be required.
2. Mount and Tripod Adjustments
Every Meade Model 4500 equatorial mount and tripod is factory inspected for proper fit and function prior to
shipment. It is unlikely that you will need to adjust, or tighten these parts after receipt of the telescope.
However, if the instrument received unusually rough handling in shipment, it is possible that some of these
assemblies can be loose. To make adjustments you will need a 1/2" or 11/16" socket or adjustable end
wrench, a 5/64" hex wrench, and a Phillips-head screwdriver.
The equatorial mount has four main areas that can be adjusted: A loose polar shaft can be tightened by
releasing a 5/64" hex set-screw that is on the side of the 11/16" polar shaft acorn cap nut (32), and then
turning the 11/16" acorn cap nut clockwise to a firm feel, and then tightening the 5/64" hex set-screw. A
loose Azimuth base (33), can be tightened by turning the 11/16" Azimuth shaft bolt (34), located underneath
the mount and in between the three tripod legs, clockwise to a firm feel. The R.A. (35), and Dec. (36) worm
block assemblies can have backlash removed by releasing the 2 Phillips-head screws on each assembly,
applying pressure to the worm block against the worm gear, and then tightening the Phillips-head screws.
Note that overtightening of any of the nuts, bolts, or screws can inhibit the smooth rotating action of the axes
and gears, and may result in stripping the threads.
The tripod legs have 1/2" nuts (39), and Phillips-head screws (38) that may have backed off, may also be
tightened to a firm feel for the most sturdy performance of the telescope.
3. Collimation (Alignment) of the Optics
All Meade Model 4500 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 Model 4500 assures the sharpest images possible.
This occurs when the primary mirror and diagonal mirror are tilted so that the focused image (see Fig. 4)
Fig. 4: The Newtonian Reflecting Telescope
Diagonal
Assembly
Diagonal Mirror
Focused Image
Primary Mirror
Primary Mirror-Tilt
Screws