Orion XT8 CLASSIC, XT10 CLASSIC Installing the CorrecTension XT Friction Optimization System

Altitude side bearing	Black nylon
Screw with
round knob	spacers

Spring

Phillips-head

screw (black)1/4" washer (black)

Pull loop

Figure 7. Close-up view of the CorrecTension system, which pulls the tube assembly down onto the altitude bearing pads.

used under dark skies and a bright setting is used under light-

polluted skies or daylight­ .

At the end of your observing session, be sure to turn the power knob counterclockwise until it clicks off. When the white dots on the EZ Finder II’s body and power knob are lined up, the EZ Finder II is turned off.

Installing the CorrecTension (XT) Friction Optimization System

Perhaps the most exciting feature of the SkyQuest Dobsonians is the CorrecTension Friction Optimization system. Because of their light weight, 10" and smaller Dobsonians have always been plagued by insufficient friction on the altitude bearing surfaces. As a result, such telescopes move up and down much too freely. This causes problems when the observer tries to accurately center and track an object for viewing, especially at higher powers. Also, the telescope becomes very sensitive to balance, requiring additional equipment such as counter- weight systems or adjustable side bearings to compensate.

SkyQuest Dobsonians employ a simple yet effective remedy for the friction problem that obviates the need for such cum- bersome countermeasures. CorrecTension Friction Optimization utilizes a spring coil to “pull” the tube assembly down onto the altitude bearing pads, thereby increasing the friction by just the right amount. With CorrecTension, you can change eye- pieces, or add a barlow lens or solar filter without having to tediously adjust the telescope’s balance as you would with other Dobsonians. The altitude friction will roughly equal the azimuth friction, ensuring optimal performance.

To install the CorrecTension assembly, follow these steps while referring to Figure 7:

1.Put one of the black nylon spacers on a black Phillips-head screw. The spacer should be oriented so the narrow end seats against the head of the screw. Slip one of the black 1/4" washers over the end of the screw. Now, thread the screw into the hole in the base side panel just below the cradle. The screw will thread into the preinstalled insert in

a.

b.

Figure 8. (a) To attach the spring to the base, grip the pull loop with your index finger and pull down on the spring. (b) While pulling down, slip the end ring of the spring over the bolt head and onto the narrow part of the nylon spacer, then release the pull loop.

the hole. Use a Phillips screwdriver to tighten the screw. Repeat this procedure on the opposite side panel.

2.Next, insert one of the screws with a round plastic knob attached through the end ring of one of the springs. Slip a black nylon spacer onto the screw. Orient the spacer so the narrow end is closest to the knob. Thread the entire assembly into the hole in the center of the telescope’s altitude side bearing until tight. The end ring of the spring should seat onto the narrow end of the spacer. Repeat this procedure for the other altitude side bearing.

3Attach a pull loop to the free end of each spring. Slide the loop through the opening in the ring on the end of the spring.

4.Now, pull each spring down using the pull loop, and posi- tion the spring’s end ring over the head of the Phillips screw (installed in Step 1) and onto the narrow part of the nylon spacer, as shown in Figure 8b. You needn’t attach both springs simultaneously; one at a time is fine.

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