The Great Polaris DX mount has a payload capacity of 22 pounds. This allows the use of midweight optical tubes, plus photoguide scopes and other equipment for advanced astrophotography. The mount has 144-tooth brass main drive gears in both right ascension and declination. To keep to a minimum the periodic error that affects tracking accuracy in astrophotography, the brass right ascension worm gear is precision machined to better than 1 micron (1/1000mm) tolerances for very precise tracking of celestial motion. The brass declination worm gear is machined to 2/1000mm accuracy precision, more than accurate enough for corrections in declination. All right ascension and declination gears are individually inspected before assembly. The end result is a higher unguided right ascension tracking accuracy for the Great Polaris DX than is possible with any lesser mount. Optional single and dual axis motor drives are available for no-hands tracking and guided astrophotography. Standard equipment covers for the optional motor drives keep dust and debris out of the motors for more trouble-free operation in dusty environments.
The Great Polaris DX has an aluminum die-cast body that's built to be strong, yet light, to satisfy both stability and ease of portability needs. The complete scope, including standard equipment 8.2 and 4.2 pound counterweights and ash tripod, weighs 42.1 pounds, making transportation and setup easy. Additional counterweights are recommended to balance payloads over 13.2 pounds.
Standard equipment right ascension and declination setting circles, used to help point the telescope at a celestial object by dialing in its coordinates, are precisely engraved in metal. The right ascension circle is marked in 10 arc minute increments, while the declination circle is marked in two-degree increments. Micrometric manual slow motion control knobs in both axes are supplied for manual tracking and centering of objects.
The Great Polaris DX has a 6 x 20mm 8-degree field polar finderscope as standard equipment. This finder allows you to align the polar axis of the scope precisely and easily on the north celestial pole, rather than just on Polaris, using the mount's altitude and azimuth fine adjustment mechanisms. Precise polar alignment allows for drift-free observing and more precise guided astrophotography. The polar finderscope comes standard with a battery-operated internal variable brightness illuminator and works in both the northern and southern hemispheres. Properly utilized, the polar finder will allow the Great Polaris DX mount to be aligned on either celestial pole with three arc minute accuracy. For those situations when Polaris is not visible, hidden behind trees or buildings, a built-in latitude scale and optional compass allow the mount to be roughly aligned on the celestial pole for casual observing. The mount is designed to operate in both northern and southern hemispheres at latitudes from 0° (the equator) to 62° (Central Canada, Northern Europe, and all of South America). Twin adjustment handles allow quick and precise setting of the latitude. Twin adjustment knobs let you fine-tune the azimuth, as well.
The mount's adjustable-height 11 pound ash tripod is stable and rigid. The tripod legs adjust in length to put the top of the tripod between 31" and 42" above ground level, to allow the observer to place the focuser at a convenient observing height for most optical tube lengths or optical tube types. Should the tripod legs not have enough extension, for example in the case of a long focal length refractor optical tube, an optional half pillar is available to fit between mount head and tripod to raise the telescope an additional 9 inches. An accessory tray keeps eyepieces and other accessories close to hand and out of the dew-laden grass. A built-in bubble level in the mount allows the mount to be quickly leveled for more accurate tracking by adjusting the length of the tripod legs independently.
The mount is equipped with a 1.8" dovetail groove for installing telescope optical tubes. No dovetail plate is supplied to hold the optical tube, as the choice of dovetail plates is dependent on the optical tube to be installed. A variety of optional dovetail plates are available. Setup and takedown times are exceptionally fast, as a single large hand-tighten knob (with a separate safety knob) holds the optical tube and dovetail plate in place.