Focus Motor for SCT and EdgeHD (Old Version)
Item #: 94155- The Celestron Focus Motor for SCT and EdgeHD enables electronic focusing using a computer or Celestron computerized mount hand controller for remote/hands-free observing.
- Self-powering: When connected to a Celestron computerized mount, the mount provides the power. When connected directly to a computer, USB provides the power.
- Compatible with a wide variety of Celestron Schmidt-Cassegrain, EdgeHD, and Rowe-Ackermann Schmidt Astrograph optical tubes. Check description for full list.
- Motor controls include multiple speed rates, automatic GoTo indexed focuser position, and focuser backlash compensation.
- Focuser Utility software for Windows provides a simple user interface. Also compatible with Celestron PWI.
- Enables autofocusing with a camera and third-party software via ASCOM.
- Indexed focus position allows the motor to automatically return to a previous focus position and prevents the focus motor from reaching the end of telescope’s mechanical focus travel.
- Not compatible with the 9.25” EdgeHD.
Overview
- The Celestron Focus Motor for SCT and EdgeHD enables electronic focusing using a computer or Celestron computerized mount hand controller for remote/hands-free observing.
- Self-powering: When connected to a Celestron computerized mount, the mount provides the power. When connected directly to a computer, USB provides the power.
- Compatible with a wide variety of Celestron Schmidt-Cassegrain, EdgeHD, and Rowe-Ackermann Schmidt Astrograph optical tubes. Check description for full list.
- Motor controls include multiple speed rates, automatic GoTo indexed focuser position, and focuser backlash compensation.
- Focuser Utility software for Windows provides a simple user interface. Also compatible with Celestron PWI.
- Enables autofocusing with a camera and third-party software via ASCOM.
- Indexed focus position allows the motor to automatically return to a previous focus position and prevents the focus motor from reaching the end of telescope’s mechanical focus travel.
- Not compatible with the 9.25” EdgeHD.
Description
The Focus Motor for SCT & EdgeHD provides electronic focusing for Celestron Schmidt-Cassegrain (SCT) and EdgeHD telescope optical tubes. With the focus motor installed, you can bring celestial objects into sharp, precise focus using your telescope’s hand controller or a computer instead of using the focuser knob. A focus motor is great for visual observers who want to dial in exact focus (especially those with dexterity issues) and a must-have accessory for astroimagers. With a motorized focuser installed, an astroimager no longer needs to be physically near the telescope to focus an image. Combined with computerized control of the mount and camera, the focus motor enables the imager to gather data remotely from a backyard observatory, or even a telescope located hundreds of miles away. As an added bonus, port covers protect the ports while not in use, and the covers cannot be lost due to the tethered design.
Compatible Optical Tubes
The focus motor is compatible with all SCTs from 6” to 14” in aperture that have been produced since the year 2006. It is not compatible with 5” SCTs or older models. It is compatible with the 8” Rowe-Ackermann Schmidt Astrograph (RASA), the 36cm RASA, the 7” Maksutov-Cassegrain, and all the EdgeHD optical tubes except for the 9.25". It can also be used with the 11” RASA, but requires the Focuser Retrofit Kit for RASA 11.
For 6” Schmidt-Cassegrain telescopes only, there are some accessories that cannot be used when the focus motor is installed due to mechanical interferences. Specifically, the Off-Axis Guider (#93648) and older 2” Mirror Diagonal (#93519, now discontinued) cannot be used.
Power Options
There are three options for powering your Celestron Focus Motor:
- When using a Celestron computerized mount, you can power and control the focus motor through the mount using the supplied AUX cable. This allows control from the mount’s hand controller (NexStar+ or StarSense) or a computer.
- If you are not using a Celestron mount, you can power and control the focus motor from a computer USB port. You will need a user supplied USB A-to-B cable.
- You may also opt to use an external 12V DC power source which plugs into the motor’s power jack.
Compatible Software
Celestron offers a free Focuser Utility program for computer control. The Celestron PWI software can also control the focus motor. To use third-party focuser control software, an ASCOM driver is needed.
Specifications
| General | |
|---|---|
| Motor: | DC servo motor |
| Spur gears: | Brass, 1:1 gear ratio, 38mm (1.49") diameter, 45 teeth |
| Focuser shaft coupler: | Aluminum clamping sleeve |
| Microprocessor: | NXP Kinetis series, Arm Coretex-M4 core |
| AUX port power: | Powered by Celestron computerized mount AUX port, connecting cable supplied |
| USB port power: | USB3 or USB2 providing at least 900mA |
| DC jack power: | 12V DC, 1A, 5.5mm (0.21") and 2.1mm (0.08") tip positive plug |
| Compatibility: | All SCTs produced after 2006 except 5" SCT, all EdgeHD except EdgeHD 9.25, RASA 8", RASA 36cm, 7" Mak-Cass |
| Speed rates: | 8°/sec , 32°/sec , 128°/sec |
| Focuser Steps per Revolution: | 1000 steps |
| Weight: | 15 oz (.42 kg) |
Accessories
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FAQ
The Focus Motor is compatible with 6 inch or larger Celestron Schmidt-Cassegrain telescopes (SCTs) built since the year 2006. I’m not sure when my SCT was built, how do I determine if the Focus Motor is compatible or not?
You can determine if the Focus Motor is compatible with your Celestron SCT by examining the design of its rear cell. This applies to fork mounted optical tubes and optical tubes with dovetail mounting bars.
Older generation Celestron SCTs built before the year 2006 are not compatible with the Focus Motor. These older optical tubes have either a flat face or a ribbed face on the rear cell. See photo examples below. 
Newer generation Celestron SCTs built in the year 2006 or later are compatible with the Focus Motor. These newer OTAs have a trilobed shape on the rear cell. In addition, newer generation 14 inch SCTs have a rounded rear cell. See photo examples below. All 6” SCTs built in 2006 or later are compatible with the focus motor. 
Installing the Focus Motor ASCOM Driver on PCs Running an Older Windows OS
The ASCOM driver must first be downloaded and installed on your Windows computer. You can find the ASCOM driver on the Focus Motor product page at www.celestron.com under the “Support and Downloads” tab. Click on the downloaded .exe file, and the driver will install on your computer. For PCs running Windows 10 OS, the Focus Motor ASCOM driver should find and connect to the Focus Motor when it is plugged into a USB port on the PC. For PCs running an earlier OS than Windows 10, the Focus Motor connection to the driver does not occur automatically. Please follow these steps to connect the Focus Motor and ASCOM driver:
1. Open this link using a browser other than Internet Explorer or Edge: http://software.celestron.com/installers/Focuser/USB_Device_Driver/
You should see a screen which looks like this:
2. Right-click on the USB_DeviceDriver.inf file, and select “Save link as…”. Then, save the file to a location on your computer.
3. Next, update the driver from the computer’s Device Manager. Locate the new hardware under “Ports (COM & LPT)” which may show a (!) symbol next to the Focus Motor indicating the device is not yet working. Right-click on the device and select “Update Driver Software…”. Then select the file path where you saved the downloaded INF file. 
4. The ASCOM driver should now connect properly to the Focus Motor.
Support & Downloads
| Manuals: |
|---|
| Focus Motor Quick Setup Guide |
| Lunar and Planetary Filter Set 1.25" Manual |
| Focus Motor Installation for the RASA 36cm |
| Software & Firmware: |
| Focuser ASCOM Driver |
| Celestron Focuser Utility Program |
| Other Product Files: |
| Focus Motor Warning Note |
| Focus Motor Dimensions |
