Table of Contents
Advertisement
Date circle
Ring with
engraved time
meridian indicator
mark
Polar scope
alignment
thumbscrew (3)
Figure 4.
The polar axis finder scope installed in the right
ascension (R.A.) axis of the mount.
the knobs, with washers attached, up through the holes in the
mount and thread them into the plate until finger tight.
10. Attach the two slow-motion cables to the R.A. and Dec.
worm gear shafts of the equatorial mount by positioning the
small screw on the end of the cable over the indented slot on
the worm gear shaft. Then tighten the screw.
11. To place the finder scope in the finder scope bracket, first
unthread the two black nylon thumbscrews until the screw
ends are flush with the inside diameter of the bracket. Place
the O-ring that comes on the base of the bracket over the
body of the finder scope until it seats into the groove on the
middle of the finder scope. Slide the eyepiece end (narrow
end) of the finder scope into the end of the bracket's cylinder
opposite the alignment thumbscrews while pulling the chrome,
spring-loaded tensioner on the bracket with your fingers
(Figure 3b). Push the finder scope through the bracket until
the O-ring seats just inside the front opening of the brackets
cylinder. Now, release the tensioner and tighten the two black
nylon thumbscrews a couple of turns each to secure the find-
er scope in place.
12. Insert the "foot" of the finder scope bracket into its mount-
ing base on top of the optical tube. Lock the bracket into
position by tightening the knurled thumbscrew on the base.
13. Insert the chrome barrel of the star diagonal into the eye-
piece adapter and secure it with the thumbscrews.
14. Then insert the 25mm Plössl eyepiece into the star diago-
nal and secure it in place with the thumbscrews on the
diagonal. (Always loosen the thumbscrews before rotating or
removing the diagonal or an eyepiece.)
15. Install the polar axis finder scope into its housing inside
the R.A. axis of the equatorial mount (Figure 4). First loosen
the three thumbscrews on the housing, which is located at the
rear of the R.A. axis. Insert the front end of the polar finder
(the end without the eyeguard) into the housing so only about
1" of the polar finder extends from the back of the housing. Do
this slowly and with a twisting motion to prevent the internal
O-ring from becoming unseated. If it does become unseated,
you can remove the entire housing from the mount to locate
Pointer
R.A. setting circle
Meridian
offset scale
Polar scope
housing
Polar axis
finder scope
Figure 5a and 5b.
requires balancing the telescope tube on the R.A. axis. (a) With the
R.A. lock knob released, slide the counterweight along the
counterweight shaft until it just counterbalances the tube. (b) When
you let go with both hands, the tube should not drift up or down.
the O-ring and reseat it. This is done by rotating the entire
housing counterclockwise. Once the polar axis finder scope is
in the housing, tighten the three thumbscrews. These thumb-
screws will be used later to align the finder with the mount's
R.A. axis.
The telescope system is now fully assembled. Keep the dust
cover over the front end of the telescope when it is not in
use.
4. getting started
Balancing the telescope
To insure smooth movement of the telescope on both axes of
motion (R.A. and Dec.) of the equatorial mount, it is impera-
tive that the optical tube be properly balanced.
Keeping one hand on the telescope optical tube, loosen the
R.A. lock lever. Make sure the Dec. lock lever is locked. The
telescope should now be able to rotate freely about the R.A.
axis. Rotate it until the counterweight shaft is parallel to the
ground (i.e., horizontal).
Now loosen the counterweight lock knobs and slide the
weights along the shaft until it exactly counterbalances the
telescope (Figure 5a). That's the point at which the shaft
remains horizontal even when you let go of the telescope with
both hands (Figure 5b).
Retighten the counterweight lock knob.
Proper operation of the equatorial mount
a.
b.
5
Advertisement
Table of Contents
