Assessments - 2, GPA: 4
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Facilidade de uso
Eyepiece thumbscrew Drawtube extension thumbscrew Focus wheel Fine focus wheel Focus wheel Drawtube tension adjustment screw Focus lock thumbscrew Congratulations on your purchase of a quality Orion 2" dual- speed low-profile Crayford focuser. This focuser is intended for use with 6" to 12" aperture Newtonian reflectors. If you do not have a Newtonian reflector, the focuser may not be appropriate for your telescope. Crayford focusers generally perform better than rack-andpinion models because the design eliminates “focus shift”. Focus shift is when an image moves position in the eyepiece when it is being focused. This is very hard to eliminate in rack-and-pinon focusers due to slight gear and tolerance imperfections which cause the drawtube to move slightly left or right when focusing. For the Crayford design, the drawtube is constantly tensioned (by the focusing shaft and four “roller bearings”) so the drawtube cannot move perpendicular to the desired motion. The 2" Dual-Speed Low-Profile Crayford focuser provides the most focus range for accessories that require extra in- travel. With a minimum focus height of 43mm, this focuser is an excellent choice for any astrophotographic system. The strong machined aluminum construction supports heavy 2" eyepieces as well as heavy camera bodies. The smooth focus motion and fine-focus wheel allow precision adjustments for critical focusing of eyepieces and cameras. Providing Exceptional Consumer Optical Products Since 1975 Installation This focuser was designed to be a “drop-in” replacement for the 2" focuser that comes standard on Orion 8" and 10" reflectors, including IntelliScope and Classic Dobsonians. If you have one of these telescopes, installing the 2" Crayford will be easy. You will need a Phillips head screwdriver and an adjustable crescent wrench or pliers. Use the following procedure: 1. Position your Newtonian reflector optical tube so it is horizontal. This will prevent any screws or nuts from falling onto the primary mirror. 2. From the inside of the tube, secure one of the four focuser securing nuts with the wrench or pliers. 3. Use the screwdriver to completely unthread the focuser attachment screw from the securing nut currently being held by the wrench or pliers. 4. Repeat this for the other three nut and screw pairs. 5. Remove the 2" focuser from the tube. 6. Place the 2" dual-speed low-profile Crayford focuser where the other focuser was previously. Orient the focuser the same as the removed one was. The through holes in the base of the focuser should line up with the holes in the telescope tube. Customer Support (800) 676-1343 E-mail: support@telescope.com Corporate Offices (831) 763-7000 89 Hangar Way, Watsonville, CA 95076 IN 316 Rev B 02/09 7. Install the four screw and nut pairs using the wrench or pliers and the included hex key. Tighten the screws firmly. Note: SkyQuest XT8 Classic Dobsonian telescopes purchased prior to 2007 will require modification to accept this focuser. If you do not have an 8" or 10" Orion Newtonian reflector, you will need to modify your tube so the focuser will fit. This will require drilling four holes into the tube for the mounting screws. Use a 3/16" drill bit to do this. Use the base of the focuser as a template when drilling these holes. You may also need to cut a larger hole (approximately 2.5" diameter) in the telescope for the bottom of the focuser. Be careful not to cut your fingers on any sharp tube edges when attempting to do this. Keep in mind that the minimum focus height for the 2" Crayford focuser is approximately 43mm, so if your eyepieces reach focus closer to the tube than this, additional modifications to the telescope may be required. The focuser can be rotated, should the need arise. This requires a 1.5mm hex key (not included). To reposition the focuser, loosen the four small socket-head set-screws that are located within the base. Rotate the focuser to the preferred position and carefully tighten the four set screws with the 1.5mm hex key. Be sure to keep the focuser flat against the base to ensure proper alignment. Usage Using the 2" dual-speed low-profile Crayford focuser is very straightforward. Place your 2" eyepiece in the focuser draw- tube, and secure it in place with the thumbscrew. Imaging cameras should generally utilize a 2" camera adapter when used with the focuser. Insert the camera adapter the same way as a 2" eyepiece. To focus, simply rotate one of the focus wheels. The large focus lock thumbscrew near the focusing shaft (see Figure 1) locks the drawtube into position once focus has been achieved. This is especially useful when using a camera or heavy eyepiece in the focuser. Be sure this thumbscrew is loosened when focusing. The socket head set screw above the focus lock thumbscrew (see Figure 1) adjusts drawtube focusing tension. If a heavy eyepiece causes the drawtube to move inward by itself (drawtube tension too loose), or the focus wheels are difficult to turn (drawtube ...