Pegasus FocusCube Zero - Celestron SCT, EdgeHD & RASA

FocusCube Zero: An Integrated 280g Motor & Controller

The core design of the FocusCube Zero eliminates the need for a separate motor controller box, streamlining your imaging setup and reducing cable clutter. The motor and the electronics are housed within a compact 52 x 58 x 35 mm enclosure. Simply mount the unit to your telescope, connect the 12V power and USB Type B cable, and you have complete control over your SCT's primary mirror focusing mechanism.

Critical Connectivity Rules for the RJ45 Expansion Port

Pegasus is explicit about this, so read it before you plug anything in. The FocusCube Zero is a standalone device with its own controller. Do not pair it with the Dual Motor Focus Controller or any other controller on the market, and do not connect its RJ45 port to the RJ45 stepper output of an Ultimate Powerbox. That RJ45 port at the back is only for the hand controller or the included temperature sensor.

Zero-Backlash Motor with 1.8° Steps for Repeatable V-Curves

Inside the enclosure is a bipolar stepper motor with a 1.8° step angle, chosen for its precise, repeatable movement. Because it uses a direct belt drive with no reduction gearbox, there is zero backlash, a critical factor for autofocusing routines that rely on consistent mechanical response. Pegasus notes that with no gearbox the speed suits moving the primary mirror in or out at very fast rates, and that it makes nearly perfect V-curves easy to achieve. A V-curve is what your autofocus routine draws as it moves from outside focus, through focus and out the other side; clean, symmetrical curves give the software a precise best-focus point.

Choosing Your FocusCube Zero: C8, C11, or C14?

Pegasus offers different versions of the FocusCube Zero to match the specific mechanics of various Celestron telescopes. The correct choice depends on your optical tube assembly, since the versions differ in the bore of the metal pulley and in the length of the screws. Pegasus gives a 1:3.75 pulley ratio (16 and 60 teeth) for the C8 and C9.25, and 1:5 (16 and 80 teeth) for the C11 and C14.

• PEG-FCZERO-SCT68925: Celestron Classic and EdgeHD 6, 8 and 9.25, and RASA 8.
• PEG-FCZERO-SCT11: Celestron Classic and EdgeHD 11, and RASA 11 V2. The RASA 11 V1 needs the Celestron retrofit kit.
• PEG-FCZERO-SCT14: Celestron Classic and EdgeHD 14, and RASA 14.

While designed for Celestron, the bracket has also been successfully fitted to some Meade SCT models that use a similar round focus knob.

Automated Temperature Compensation with the Included 0.6m Probe

As ambient temperature drops during the night, your telescope's metal tube and optics contract, causing the focal point to shift. The FocusCube Zero includes a 0.6 m external temperature probe that plugs into the RJ45 expansion port. Place the probe near the focuser and the temperature of the focuser and its surroundings shows in the Pegasus software or the ASCOM driver, so your capture software can refocus on a temperature change instead of waiting for stars to soften.

Full System Control via Unity, ASCOM, and INDI

The FocusCube Zero integrates seamlessly with all major astrophotography software platforms. The Pegasus Unity Platform gives full control and configuration, and its REST JSON API lets third-party software talk to the device. The FocusCube Zero is fully compatible with ASCOM 6, its INDI driver is part of stable libindi, and third-party TheSkyX X2 drivers exist for Windows, Linux and OSX. Firmware can be re-flashed over USB with the Pegasus upgrade software (Windows only), and Pegasus keeps adding features based on customer feedback.

Installation on Your SCT with the Margarita Bracket System

Mounting the FocusCube Zero is straightforward with the included black anodized aluminum "margarita style" bracket. The process involves removing the telescope's rubber focus knob, fitting the bracket over the focuser base, and attaching the large pulley to the focuser shaft. The motor assembly slides on the bracket's oval holes, allowing you to set the correct tension on the transmission belt before tightening the four mounting screws. All necessary screws and hardware for mounting to the telescope are included in the box.