iOptron GEM45 Mount

A 2.53 Payload-to-Weight Ratio: 45 lb Capacity on a 17.5 lb Head

iOptron says experience from its CEM series let it remove unnecessary bulk from the GEM45. The all-metal, CNC-machined mount head weighs 17.5 lbs (7.9 kg), or 18 lbs (8.2 kg) on NUC-Ready versions, and carries up to 45 lbs excluding counterweight.

Precision Drive Train: Φ110mm Worm Wheels and Φ45mm Shafts

Both the Right Ascension and Declination axes are built around solid Φ45mm steel shafts turning on large Φ68mm bearings. These are driven by Φ110mm, 216-tooth aluminum worm wheels, which are paired with a Φ17mm brass worm and a synchronous belt transmission from the stepper motors.

• Zero Backlash Design: iOptron lists both worm wheels as zero backlash.
• Stepper Motor Drive: A 1.8° stepper motor with 128x micro-stepping gives a motor resolution of 0.08 arcseconds.
• Construction: All metal, CNC machined, with an anodized red/black finish.

Two Tiers of Tracking: <±7.5" PE or <0.3" RMS with EC Encoders

The GEM45 is offered in two levels of tracking accuracy to suit different imaging demands. The standard GEM45 has a periodic error of less than ±7.5 arcseconds and Permanent Periodic Error Correction (PPEC): the hand controller records the periodic error and plays back the correction.

GEM45EC versions add a high-resolution encoder to the RA axis. This system provides Real-time Periodic Error Correction (RPEC), correcting drive errors as they happen. This brings the periodic error to < 0.3 arcseconds RMS.

Fast, Accurate Setup with the Internal iPolar Scope

Every iOptron GEM45 mount includes the internal iPolar electronic polar scope. You install the iPolar software, connect the mount to a computer by USB and follow the on-screen instructions to adjust altitude and azimuth. iOptron says polar alignment is a snap even when the pole star is obscured, and the manual says it is simple and fast even when part of the sky is blocked.

GoTo Navigation with the Go2Nova 8410 Controller

Navigating the sky is handled by the Go2Nova® 8410 hand controller and its extensive 212,000+ object database. The controller has an 8-line, 21-character LCD and an integrated heater that keeps it working down to -10ºC. Once aligned, the mount can slew to any object at up to 4.5° per second. An external GPS module, included, provides your location and time.

• Automatic Zero Search: The mount can automatically find its zero position.
• Power-Down Memory: iOptron lists power-down memory, so the mount remembers its position if power is lost.
• Meridian Treatment: You can configure the mount to automatically perform a meridian flip, or to continue tracking up to 20° past the meridian before stopping.

Connectivity for Control and Autoguiding

A standard USB port provides a direct connection to a PC for mount control via the iOptron ASCOM driver. For autoguiding there is an ST-4 port, and guiding through ASCOM is also supported. Wi-Fi requires the optional iStarFi adapter (#7434), which plugs into the iPort, for control from a smartphone, tablet or computer.

Integrated Cable Management and Dual Dovetail Saddle

iOptron says there is little chance of your cables getting snagged with the GEM45's internal cable management system.

• Accessory Ports: Standard versions include DC12V (3A) power output, an ST-4 port, and a USB port.
• NUC-Ready Versions: These models add DC (5A), GUIDE and USB ports plus DC 19V, LAN and USB connections for an Intel NUC mounted at the front of the saddle (NUC not included).
• Dual Saddle Plate: The 6" dovetail saddle accommodates both Losmandy-D and Vixen-style dovetail bars,

Low-Consumption 12V Power System

The GEM45 runs on 12V DC, 5A (5.5mm/2.5mm plug). Power consumption is 0.6A while tracking and 0.9A during GoTo. A universal 100V ~ 240V AC adapter is included for powering the mount from a mains outlet.

Choosing Your GEM45: A Breakdown of All Configurations

The iOptron GEM45 is available in multiple configurations to match your existing equipment and imaging goals. All versions include the mount head, internal iPolar, Go2Nova 8410 hand controller, and counterweight shaft.

• Head Only Versions (GEM45 / GEM45EC): Includes the mount head in a hard case. These versions do not include a tripod or counterweight.
• LiteRoc Tripod Versions (GEM45 / GEM45EC): These packages include the 1.75" LiteRoc stainless steel tripod (about 8 kg) and one 11 lb (5 kg) counterweight. All but the GEM45 w/ iPolar & LiteRoc also include a hard case.
• iGuider Version: This package includes the LiteRoc tripod, case, and the iGuider guiding scope and camera built into the dovetail saddle.
• NUC-Ready Versions (GEM45 / GEM45EC): These complete packages feature a modified saddle ready to carry an Intel NUC mini-computer, with dedicated NUC power, LAN and USB connections.