MOTOFOCUS Configuration Information for Certain GSO and William Optics Focusers

These MOTOFOCUS units all use miniature motors.

GSO / William Optics 2" 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.  Several of these configurations are described here.  (Due to many manufacturing variations, this information may change at any time.)  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 rear or drive block side, including the whole focuser in the picture.  See Figure One and Figure Two (below) for an example, but be sure to take the picture of the whole focuser.

THE BOTTOM LINE:  Due to the pervasive confusion about Make and Model for these focusers (we admit it, WE are confused!), we recommend that you only use the drive block configuration pictures (below) to verify that you are purchasing the correct MOTOFOCUS unit for your focuser.  Please look at ALL configurations before making a decision.  Make, model and other description information is only a rough guide.



SUMMARY OF CURRENT CONFIGURATIONS
NOTE:  See pictures of the various configurations below this summary chart.  To be sure that you get the correct MOTOFOCUS for your Microfocuser equipped GSO/WO focuser, you can email a picture of the focuser's drive block from the angle shown in Figure One and Two (below), including the whole focuser in the picture.  We may request measurements of certain parts of your focuser.  In some cases, we may need to have you ship your focuser to us in order to verify the configuration and/or complete your order.

EARLY VERSION WITHOUT MICROFOCUSER
Configuration ONE (see Figure ONE) 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 TWO) has a focuser tensioning screw above (not directly in line with) the drive shaft and a brake tensioning screw below the drive shaft.

EARLY VERSION WITH MICROFOCUSER
Check the pictures (Figure THREE) 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 (identified by 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.

Without MOTOFOCUS	With MOTOFOCUS Attached
Figure THREE

LightBridge DUAL-SPEED FOCUSER
The GSO Dual-Speed Focuser used on the Meade LightBridge Telescope is configuration FOUR (see Figure FOUR).  Please note that the single-speed focuser used on the Meade LightBridge Telescope should match configuration TWO above.

Meade LightBridge Dual-Speed Focuser

Figure FOUR

MEGREZ 90 FOCUSER AND REPLACEMENT FOCUSER FOR SYNTA-MADE REFRACTORS
The following pictures (Figure FIVE) show the replacement focuser for Synta Refractors and the focuser used on the Megrez 90.  Some FLT focusers may match this style (undetermined at this time).  These focusers are designated as configuration FIVE.

Megrez 90 Focuser with MOTOFOCUS	Replacement Focuser for Synta-Made Refractors	Synta Replacement Focuser with MOTOFOCUS
Figure FIVE

MEGREZ 110 FOCUSER
The following picture (Figure SIX) shows the focuser used on the Megrez 110.

Megrez 110
Focuser

Figure SIX

SKY-WATCHER EQUINOX 80, 100 AND 120 PRO ED FOCUSER
The following picture (Figure SEVEN) shows the dual-speed Crayford focuser used on the Sky-Watcher Equinox 80 / 100 / 120 Pro ED.

Sky-Watcher Equinox 80 / 100 / 120 Pro
Dual-Speed Focuser

Figure SEVEN

WILLIAM OPTICS ZENITHSTAR 110 APO FOCUSER
The following picture (Figure EIGHT) shows the dual-speed Crayford focuser used on the William Optics ZenithStar 110mm APO.

William Optics ZenighStar 110 APO
Dual-Speed Focuser

Figure EIGHT

WILLIAM OPTICS Star 71 FOCUSER
The following picture (Figure NINE) shows the dual-speed Rack-and-Pinion focuser used on the William Optics Star 71.

    

William Optics Star 71 Dual-Speed Focuser
Showing Drive Block (left) and Complete MOTOFOCUS System (right)

Figure NINE

SKY-WATCHER PRO AND BLACK DIAMOND 80ED AND 120ED REFRACTOR FOCUSERS
The following picture (Figure PRO) shows the dual-speed Crayford focuser used on the Sky-Watcher Pro 80ED (Black Diamond)

    

Sky-Watcher Pro 80ED (Black Diamond)
with MOTOFOCUS Attached (left) and Drive Block Only (right)

Figure PRO

WILLIAM OPTICS DIGITAL DISPLAY GAUGE (DDG) FOCUSERS
The following pictures (Figure DDG) show the version 1 and version 2 of the Digital Display Gauge focusers.  (The Digital Display Gauge is actually optional but that does not affect the MOTOFOCUS model you need to purchase.)

Digital Display Gauge (DDG)
Version 1 (left) and Version 2 (right)

Figure DDG

ORION EON 130 FOCUSER
The following pictures (Figure EON) show the Orion EON 130 ED Crayford Focuser.

Orion EON 130
with MOTOFOCUS Attached (left) and Drive Block (right)

Figure EON

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