Orion Understanding CorrecTension Friction Optimization for Dobsonian Telescopes

SkyQuest Intelliscope Dobsonians employ a simple yet effec- tive remedy for the friction problem that obviates the need for such cumbersome countermeasures. CorrecTension Friction Optimization utilizes a simple “disc brake” to apply the correct level of tension to the altitude bearings. With the XT system, you can change eyepieces or add a barlow lens without hav- ing to tediously adjust the telescope’s balance as you would with other Dobsonians. The altitude friction can be made equal to the azimuth friction, ensuring optimal performance.

Figure 10. The tensioning knob, with the metal and nylon washers, goes on the side of the base with the IntelliScope port. The tensioning knob should be tightened until the CorrecTension pads just touch the telescope’s altitude bearing.

Figure 11. The retaining knob with the nylon spacer is installed on the side of the base that does not have the IntelliScope port.

To install the XT system, follow these steps while referring to Figures 10 and 11:

1.Select one of the retaining/tensioning knobs and slide the metal washer onto the shaft, followed by the white nylon washer (you will need to thread this washer onto the shaft). This knob will now be known as the tensioning knob.Push the shaft of the tensioning knob through the hole in the side panel that has the IntellisScope port (Figure 10). Thread the knob into the altitude bearing until the CorrecTension

pads on the interior surface of the side panel just touch the side of the altitude bearing on the optical tube.

2.Place the black nylon retaining knob spacer on the shaft of the remaining retaining/tensioning knob. This knob will now be known as the retaining knob. Push the shaft of the retaining knob through the hole in the side panel opposite the one the retaining knob is in (Figure 11). Thread the knob into the altitude bearing as far as it will go. The purpose of this knob is to allow the tube and base to be carried as a single unit as well as to engage the altitude encoder when using the IntelliScope controller. There will be a gap of 1/2" between the side panel and the side bearing; this was designed deliberately for use of the IntelliScope controller system.

Note: Only the left side panel has a while nylon bushing in the hole for the tensioning knob. The right side panel

does not require this bushing.

The CorrecTension system is now installed. If you wish to remove the optical tube from the base, you will first need to unthread and remove both the knobs (and spacers/wash- ers). Once the optical tube is removed from the base, thread the knobs back into the altitude bearings so you do not lose them.

Installing the Finder Scope

SkyQuest IntelliScope Dobsonians come with a high-quality, large-aperture 9x50 (6x30 for the XT6) achromatic crosshair finder scope (Figure 12a) as standard equipment. This greatly aids in finding objects to view in the night sky.

To place the finder scope in the finder scope bracket, first unthread the two black nylon screws until the ends are flush with the inside of the bracket. Place the rubber 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 bracket as shown while pulling the chrome, spring-loaded tensioner on the bracket with your fingers (Figure 12b). Push the finder scope through the bracket until the O-ring seats just inside the front opening of the bracket. Now, release the tensioner and tighten the two black nylon screws a couple of turns each to secure the finder scope in place. Insert the base of the finder scope bracket into the dovetail holder located adjacent to the focuser. Lock the bracket into position by tightening the knurled thumbscrew on the dovetail holder.

Finder scope	Finder scope bracket
	Nylon
	alignment
	thumbscrew (2)

	Eyepiece
Focusing lock ring	Tensioner

Figure 12a. The 9x50 finder scope and bracket (6x30 for the XT6).

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