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GSO vs WO Configurations for MOTOFOCUS

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MOTOFOCUS Configuration Information for Certain GSO and William Optics Crayford Focusers

These MOTOFOCUS units all use miniature motors.

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.  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.

Part Numbers by
Drive Block Configuration

Drive Block
Configuration

Part
Number
Possible Compatible Equipment
1 MFWO1 GSO/William Optics Early Version Crayford Focuser w/o Microfocuser
2 MFGSO2 GSO/William Optics Early Version Crayford Focuser w/o Microfocuser
Meade LightBridge Single-speed Crayford Focuser
3 MFWO3 GSO/William Optics Early Version Crayford Focuser with Microfocuser
4 MFGSO4 Meade LightBridge Dual-speed Crayford Focuser
5 MFWO5 William Optics Megrez 90 Focuser
William Optics Replacement Focuser for Synta-made Refractors
6 MFWO6 William Optics Megrez 110 Focuser
7 MFWO7 Sky-Watcher Equinox Pro 80/100/120 ED
Smart Astronomy Dual-speed Crayford Focuser
Stellarview 2" Dual-speed Crayford Focuser
William Optics Megrez 72ED
William Optics Zenith Star 70 APO
Pro MFSWPRO(+) Sky-Watcher Pro 80ED / 120ED (Black Diamond)
Orion XT8 / XT8g Dobsonian with Dual-speed Focuser
DDG1 MFWODDG1 William Optics Focusers with Digital Display Gauge (DDG)
DDG2 MFWODDG2 William Optics Focusers with Digital Display Gauge (DDG)



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



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 picture (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

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