Orion 8 EQ Balancing the Telescope, Installing the Finder Scope, Inserting the Eyepiece, a.b c.d

1.25" eyepiece	2" eyepiece adapter
adapter

	Focus lock
	thumbscrew
Focus
		Collimation
knobs
		screw pair
		(3)

Figure 4. The 2" focuser of the Atlas 8 EQ.

place to keep the hand controller out of the way when not in use. Place the “hooks” strip of nylon adhesive on the back of the hand controller and the “loops” strip on a tripod leg or on the mount where it will be in a conveniently reached spot. Simply hang the hand controller by the nylon adhesive when it is not in use. Make certain when you attach the nylon adhesive to the mount that the hand controller’s posi- tion will not interfere with the motion of the mount.

Installing the Finder Scope

To place the finder scope (Figure 3a) in the finder scope brack- et, 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 slot 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 screws while pulling the chrome, spring-loaded ten- sioner 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 bracket cylinder. Release the tensioner and tighten the two black nylon thumbscrews a cou- ple of turns each to secure the finder scope in place. Insert the base of the finder scope bracket into the dovetail holder on the optical tube near the focuser. Lock the bracket into position by tightening the knurled thumbscrew on the dovetail holder.

Inserting the Eyepiece

Loosen the thumbscrew on the 1.25" adapter (Figure 4) and remove the small dust cap. Insert the 25mm eyepiece into the focuser and secure it with the thumbscrew.

Your Atlas 8 EQ is now fully assembled and should resemble Figure 1. Keep the dust cover on the front of the telescope when it is not is use.

Note about the Atlas 8 EQ Mount Weight

The Atlas 8 EQ mount is very heavy. Alone it weighs 54 lbs. With the optical tube and counterweights it weighs almost 100 lbs. Keep this in mind when moving the telescope even small

a.b.

c.d.

Figure 5a-d.Proper operation of the equatorial mount requires that the telescope tube be balanced on the R.A. and Dec. axes. (a) With the R.A. lock lever released, slide the counterweights down the counterweight shaft until they just counterbalance the telescope tube. (b) When you let go with both hands, the tube should not drift up or down. (c) With the Dec. lock lever released, loosen the tube ring lock clamps a few turns and slide the telescope forward or back in the tube rings. (d) When the tube is balanced about the Dec. axis, it will not move when you let go.

distances, and use assistance when needed. It is best to remove the optical tube and counterweights when moving the mount, or extending the tripod legs.

4. Balancing the Telescope

To ensure smooth movement of the telescope on both axes of the equatorial mount, it is imperative that the optical tube is prop- erly balanced. We will first balance the telescope with respect to the right ascension (R.A.) axis, then the declination (Dec.) axis.

1.Keeping one hand on the telescope optical tube, loosen the R.A. lock lever. Make sure the Dec. lock lever is locked, for now. The telescope should now be able to rotate freely about the right ascension axis. Rotate it until the counter- weight shaft is parallel to the ground (i.e., horizontal).

2.Now loosen the counterweight lock knobs and slide the weights along the shaft until they exactly counterbalance the telescope (Figure 5a). That’s the point at which the shaft remains horizontal even when you let go with both hands (Figure 5b).

3.Retighten the counterweight lock knobs. The telescope is now balanced on the right ascension axis.

4.To balance the telescope on the declination axis, first tight- en the R.A. lock lever, with the counterweight shaft still in the horizontal position.

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