MOTOFOCUS Configuration Information for Certain GSO and William Optics Crayford Focusers

GSO / William Optics 2" Crayford focusers including SCT and Maksutov Cassegrain focusers, Newtonian focusers, Dobsonian focusers (Meade Lightbridge) and original-style replacement focusers for Synta-made refractors (Sky-Watcher, Celestron, Orion and more).

NOTE:  There has been a lot of confusion between GSO (Guan Sheng Optical Co. Ltd. in Taiwan) and William Optics focusers and their differing configurations.  Where the focuser has been used consistently on a particular telescope (such as the Meade Lightbridge series) the focuser can be identified by the telescope.  In other cases, one may need to look at identifying characteristics of the particular focuser in order to purchase the correct MOTOFOCUS unit.  Three of these configurations are described here.  (Due to many manufacturing variations, this information may change at any time.)

WITHOUT MICROFOCUSER
Configuration ONE (see figure 1) has a focuser tensioning screw that is directly in line with (not above) the drive shaft and a brake screw below the drive shaft.  Configuration TWO (see figure 2) has a focuser tensioning screw above (not directly in line with) the drive shaft and a brake tensioning screw below the drive shaft.

WITH MICROFOCUSER
Check the pictures below (click to enlarge) to verify if you have configuration THREE.  Notice the positioning of the thumb screws (as explained above), the shape of the Microfocuser housing and the type of slow-speed knob.  The MOTOFOCUS unit slips over the slow-speed knob.  We have seen both black and purple versions.

At this time, our MOTOFOCUS is based on one or more of the following characteristics:

1)  The tension and brake screw alignment (see above).  This configuration matches Figure One above.
2)  The diameter of the slow-speed knob (based on the knurling of the adjacent knob?).  Compare with the picture below.
3)  The shape of the Microfocuser housing (rounded or flat).  This configuration is rounded.

NOTE:  To be sure that you get the correct MOTOFOCUS for your Microfocuser equipped GSO/WO focuser, you can email a picture of the focuser from the angle shown in figure one and two (above), including the whole focuser in the picture.

Without MOTOFOCUS	With MOTOFOCUS Attached
Figure THREE

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