Orion XT12 - Manual (Page 5)

5
Assembling the SkyQuest XT12 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 verti-
cally so that the raw edge of the tube is facing upwards. 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 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 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 8). Replace the six Phillips-head screws
that connect the rear end ring to the tube.
Assembly of the Dobsonian Base
Refer to Figure 9 during base assembly. The base need only
be assembled once, unless you disassemble it for long-term
storage. The assembly process takes about 30 minutes and
requires, in addition to the supplied tools, a Phillips screw-
driver, and two adjustable crescent wrenches. You can
substitute a 10mm crescent wrench for one of the adjustable
crescent wrenches, or use a pair of pliers.
The azimuth encoder board and other encoder items should
be installed, even if you do not plan to use the optional
Computerized Object Locator. The smooth motion of the tele-
scope depends on the installation of these parts.
When tightening screws, tighten them until firm, but be careful
not to strip the holes by over-tightening. If you use an electric
screwdriver, do final tightening with a standard screwdriver to
avoid stripping.
Figure 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.
Figure 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 7. Locate the area of tube that is bulging out and
preventing the mirror cell from fully seating.
Figure 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.