Orion XT8 CLASSIC, XT10 CLASSIC instruction manual Assembly of the Dobsonian Base

	C
		C
		B
		L
		I
J		H
		E
	D
	A	K
		F
		G

Figure 2. Exploded view of the SkyQuest XT Dobsonian base.

2. Assembly

Now that you have unpacked the boxes and familiarized your- self with all the parts in front of you, it’s time to begin assembly. The optics of the telescope are already installed in the tube, so most of the required assembly concerns the Dobsonian base.

Assembly of the Dobsonian Base

Refer to Figure 2 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 a Phillips screwdriver, an adjustable crescent wrench, and the provided hex keys.

Note: When tightening the base assembly screws, tight- en them until firm, but be careful not to strip the holes by over-tightening. If you use an electric screwdriver, do the final tightening with a standard screwdriver to avoid stripping.

1.Screw the plastic feet into the underside of the ground baseplate (A) using the self-tapping wood screws provid- ed, with a Phillips screwdriver. 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 label is facing outward. Do not completely tighten the screws yet.

Figure 3. Set the optical tube on the “cradle” of the base so that the altitude side bearings on the tube rest on the white plastic “pads,” and the finder is facing away from the front brace (Part B).

3.Attach the two sides (C) with the front brace attached to the top baseplate (D) with the remaining six base assembly screws in the predrilled holes. Tighten all six screws.

4.Tighten the six side panel screws installed earlier.

5.Insert the white nylon bushing (E) into the hole in the cen- ter of the top baseplate (D). Tap the nylon bushing in so it goes all the way into the top baseplate. The nylon bushing should be flush with the top surface of the top baseplate.

6.Insert the T-nut (K) into the center hole of the ground base- plate (A) so the nut’s flanged top is on the same side of the baseplate as the Teflon pads. Thread the large hex-head bolt (G) with a 3/8" washer (F) attached up through the ground baseplate and through the T-nut until it is tight. Now position the top baseplate (D) (with side panels attached) over the ground baseplate and lower it so the bolt goes through the nylon spacer in the center hole of the top baseplate. Now thread the remaining 3/8" washer (H) and lock nut (I) onto the bolts shaft. You might need to hold the bolts head in place with another crescent wrench or pliers. Tighten the lock nut with the wrench just enough to allow a slight separation of the top and bottom baseplates when the mount is lifted. The purpose of the lock nut is merely to keep the two baseplates from coming apart when moving the telescope.

Note: Overtightening the lock nut (I) will make the mount difficult to rotate in the azimuthal (horizontal) direction.

7.Attach the handle (J) to the front brace (B) with the two black socket-head screws. Insert the screws through the handle and into the predrilled holes. Place the 5/16" wash- ers and 5/16" nuts on the protruding ends of the screws. Tighten the nuts with a crescent wrench while holding the bolts stationary with the 6mm hex key.

8.Lift the optical tube and set the altitude bearings on either side of the tube in the “cradle” of the base (Figure 3). The unique flange design of the altitude bearing allows for auto- matic left-to-right centering of the optical tube in the cradle.

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