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Telescope
side bearings
Bearing
cylinders
(x4)
Figure 8. Gently set the telescope into the base by resting
the side bearings of the telescope on the bearing cylinders.
installing the Optical Tube assembly on the Base
1.
Lift the optical tube and gently place it into the Dobsonian
base so that the altitude bearings on either side of the
tube rest on the bearing cylinders (Figure 8). Take care
when lowering the telescope not to catch the ring of
reddish material attached to the telescope tube's left
side bearing on the top edge of the base's left side
panel, or the ring could come off (it is held on the
side bearing with adhesive). Make sure the optical tube
is oriented as shown, with the focuser facing the left side
panel. Once the tube is resting on the bearing cylinders,
the tube should pivot freely up and down with gentle
hand pressure. Note that the tube will not yet be properly
balanced, since the eyepiece and EZ Finder II are not in
place, and the altitude axis coupling knobs are not yet
installed.
2.
Now insert the bolt of one of the altitude axis coupling
knobs through the bushing in the RIGHT side panel and
turn the knob to thread the bolt into the threaded insert
6
Figure 9. Assembling the tensioning knob. First place a
metal washer on the bolt, then thread on the white, low-
friction washer until it is all the way on. Both washers will now
be held captive on the bolt.
Left
side panel
Tensioning
knob
Figure 10. The tensioning knob on the left side panel lets
you set and adjust the amount of friction for the altitude
motion of the telescope.
of the tube assembly's right side bearing. Thread the bolt
until it stops and the knob is lightly tightened.
3.
On the other altitude axis coupling knob place a metal
washer on the bolt, then thread on the white plastic
washer all the way (Figure 9), until it is captive on the
smooth portion of the shaft nearest the hand knob. Now
insert the bolt though the bushing on the LEFT side
panel and use the knob to thread it into the left side
bearing on the optical tube assembly. This coupling knob
is referred to as the "tensioning knob" (Figure 10).
Low-friction
washer
Metal
washer
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