Orion XT12 User Manual

Page 6

1. With a Phillips screwdriver, screw the plastic feet into the

underside of the ground baseplate (A) using the self-tap-
ping wood screws provided. Insert the screws through the
feet and thread them into the predrilled starter holes.

2. Loosely attach the front brace (B) to the two side panels

(C) with six of the base assembly screws in the predrilled
holes. Use the 4mm hex key to tighten the screws. The side
panels should be oriented so the SkyQuest IntelliScope
labels are facing outward. Do not completely tighten the
screws yet.

3. Connect the two side panels (C) with the front brace

attached to the top baseplate (D) with the remaining six
base assembly screws in the predrilled holes. The side of
the baseplate with the pilot hole near the square-shaped
cutout should be facing downwards. Tighten all six screws
firmly.

4. Tighten the six base assembly screws installed in step 2.
5. Attach the azimuth encoder board (E) to the underside

of the top baseplate (D). Insert the modular jack on the
encoder board into the square-shaped hole in the base-
plate and align the encoder board so that the small slotted
hole in the board lines up with the predrilled starter hole,
and the large hole lines up with the central hole in the
baseplate (Figure 10). Thread an encoder board mounting
screw into the predrilled starter hole with a Phillips screw-
driver and tighten until just tight.

6. Place one fender washer (H) onto the azimuth axis screw

(I). Then push the screw up through the hole in the ground
baseplate (A).Then slide the encoder disk (J), flat side
down, onto the azimuth axis screw.

7. Place the brass bushing (F) onto the azimuth axis screw

(I) so that the wide end of the bushing is closest to the

encoder disk (J). Seat the bushing onto the encoder disk
so that the registration feature on the bushing goes into
the hole in the encoder disk. You may need to move the
encoder disk around on the azimuth axis screw a bit in
order for the bushing to seat properly.

8. Carefully position the top baseplate (D) over the ground

baseplate (A) and lower it so the brass bushing (F) goes
into in the center hole of the top baseplate. Place the
remaining fender washer (K) onto the shaft of the azimuth
axis screw, then thread the hex lock nut (L) onto the end of
the azimuth axis screw and tighten it finger tight, for now.

9. To tighten the azimuth axis screw (I) and hex lock nut

(L), tilt the assembled Dobsonian base at a slight angle
to lift the ground baseplate off the ground. Now, with one
wrench (or pliers) hold the head of the azimuth axis screw
still while turning the hex lock nut with the other wrench.
Figure 11 shows this being done. Tighten the hex lock nut
just until the top fender washer is no longer moving freely,
then tighten the hex nut 3/16-1/4 turn beyond that. This
ensures proper spacing between the encoder disk and the
azimuth encoder board.

10. Attach the handle (M) to the front brace (B) with the two

handle mounting hex-head screws. Place one washer
on each screw, then press the handle against the front
brace (the end of the handle with the logo should be fac-
ing upwards). Thread the screws from the inside of the
base into the handle until tight using the supplied crescent
wrench.

11. Line up one of the altitude bearing cylinders with one of

the four bearing cylinder holes on the interior of the side
panels. The beveled end of the cylinder should be facing
away from the side panel. Push a bearing cylinder screw
through the side panel and bearing cylinder. Then thread
it into the built-in hex nut on the cylinder with a Phillips
head screwdriver (Figure 12). Repeat this for the remain-
ing three bearing cylinders.

12. Attach the encoder connector board to the interior sur-

face of the left side panel. Place the board against the side
panel so that the modular jack fits into the square-shaped
hole and thread four encoder board mounting screws
through the connector board and into the predrilled holes
in the side panel until tight (Figure 13).

Figure 9.

Exploded view of the Dobsonian base.

Figure 10.

To install the azimuth encoder board, line up the

large hole in the encoder board with the central hole in the top
baseplate.

Encoder board

mounting screw

Azimuth encoder board