Gemini 2 Retrofit kit S go-to computer and upgrade motors for Losmandy German equatorial mounts


Availability: More on the way

The Losmandy Gemini 2 retrofit kit S is a stand-alone computer control and DC servo motors package that adds computerized go-to to the Losmandy GM-8, G-11, and HGM 200 German equtorial mounts . . .
Our Product #: LGT
Losmandy Product #: Gemini 2 Kit
Recommended Accessories

Product Description

The Losmandy Gemini 2 system is a DC servo motor-based go-to computerized positioning system designed for the Losmandy GM-8, G-9, G-11, and HGM 200 mounts. The Gemini 2 can be ordered factory-installed on all new Losmandy mounts. It is also easily retrofitted to an existing mount by users who already own one of the mounts listed above. The Gemini 2 simply replaces the existing stepper drive motors and electronics of your existing mount with new electronics and servo motors. A few hex keys and a small pair of pliers are the only tools required to upgrade your drive to full go-to capabilities.

The upgraded DC servo motors supplied with the Gemini 2 have higher torque through their entire range of tracking and slewing speeds than the motors on standard Losmandy mounts that don't have a go-to capability. The drive system has a dual 12~18V DC input/output and draws 3.0A maximum.

The servo motors used in the Gemini 2 have two main advantages over the stepper motors normally used in scopes. First, servo motors run with a continuous smooth rotation, rather than the discrete short steps taken by stepper motors. This results in less image "jitter" in extremely high magnification planetary observing and stars that are tighter and more point-like in critical astrophotography applications. Second, servo motors have very high torque, even at high slewing speeds. As a result, the Gemini 2 system can deliver up to 8 degrees per second slewing with the GM-8 mount. The maximum slew rate with the heavier-payload HGM Titan and G-11 mounts will be approximately 6 degrees per second.

The Gemini 2 computer is a stand-alone system, with no PC required for operation in the field. A full-color graphic touch screen on the hand control of the Gemini 2 system clearly displays all functions. There is a classic four-button diamond pattern for guiding, centering, moving, and slewing on both the touch screen on the front of the computer and on a tactile four-button membrane on the rear. There is also support for the original Gemini four-button controller.

The Gemini 2 has 0.5 arc second positioning accuracy during go-to operation. It is GPS-compatible with an optional #LGPSG2 receiver. It has Ethernet 10/100 with full IP function to permit operation from anywhere using a browser, ASCOM, or an application over the web or serial port. There is also custom mount support using a programmable gear rate function.

The more than 40,000 object memory of the Gemini 2 is non-volatile and the system contains a real-time clock. You can select from English, French, and German language displays. There are two USB ports; one for virtual COM to PC, and one for an ASCOM or planetarium program. There is PEC correction built in and an auto-guider port. The firmware can be upgraded via the internet. There are ports for future high-resolution encoders and a multi-function A/D I/O serial port.

The following databases, comprising about 41,000 stars and objects, are built into the Gemini 2 system, more than enough to keep even the most avid observer busy for some time! You get the Messier catalog (110 objects), the revised NGC catalog (7840 objects), the revised IC catalog (5386 objects), the Sh2 Sharpless 2 catalog (313 objects), a catalog of 167 bright stars, and a 17,635 star catalog of SAO stars.

The image above shows the Gemini 2 installed on a Losmandy G-11 mount.

Tech Details

Weight 4.2 lbs.
Warranty 1 year


Review by:
I have used this kit on all 3 of my non-Gemini or non-Gemini II to improve the characteristics of the mount and improve its use for astrophotography. The older Losmandy mounts had backlash that the Gemini systems allow to be programmed out similar to a PEC function. Nice! (Posted on 7/22/2019)
How do you rate this product? *