iOptron CEM40 with iGuider Center Balanced Equatorial GoTo Mount

iOptron CEM40 with iGuider Center Balanced Equatorial GoTo Mount

  (1 Review)
✓ 2 year warranty


Out of stock due 40-60 working days

About this product

Model:  iop_cem40ag
Part Number:  C402AG3

New CEM40 with built-in iGuider and iPolar!

The iOptron® CEM40G mount is the next generation of center-balanced equatorial mounts with a built-in iGuider guiding camera. This mount is incredibly eye-pleasing, and its beauty is found in more than its appearance. The functionality of the mount is superb. Weighing in at only 7.9kg / 17.4lbs., the CEM40G can support a payload of up to 18kg / 40lbs.! That's incredible!

This mount also has an integrated electronic polar finder scope known as the iPolar. This tool ensures the accurate alignment of a telescope, even when the pole star is obscured. There are large levers on the quick-lock drive engagement system; these large levers make it easy to snap the gears into place.

Innovative iOptron Technology

Make way for an innovative mount! This iOptron CEM40G mount has a dual saddle that accommodates Losmandy and Vixen-style dovetail plates. The CEM40 also uses iOptron's ultra-quiet, low-power consumption stepper motor drive system, aiding the mount in providing precise tracking.

Computerized Mount Features

The iOptron CEM40 mount uses the Go2Nova® 8407 hand controller to navigate the night sky. This incredible technology helps observers find celestial objects with the aid of the mount's 212,000+ object database! For those looking for a telescope that has the capability of tracking and finding beautiful night sky objects, this mount is a must have tool.

With the included tripod, 5kg / 11lbs. counterweight, and the mount's computerised technology, observers are just an OTA away from a spectacular viewing experience!


  • Unique design, Center-Balanced equatorial mount (CEM) for maximum payload and minimum mount weight
  • Built-in iGuider guiding camera
  • Idea for both visual observation and astrophotography
  • Maximum payload of 40 lbs (18 kg) with the mount weight of only 17.4 lbs (7.9 kg)
  • All metal, CNC machined with red/black anodized
  • Easy to use quick-lock gear clutches
  • Integrated iPolarTM electronic polar finder
  • Low periodic error (< ± 7 arc seconds)
  • Permanent periodic error correction (PPEC)
  • Precision stepper motor for precise GOTO and accurate tracking
  • Go2Nova® 8407+ controller with Advanced GOTONOVA® GOTO Technology with built-in heater
  • Integrated ST-4 autoguiding port
  • 32-channel Global Positioning System (GPS)
  • USB communication port
  • Cable management system
  • Vixen, Losmandy dual saddle
  • LiteRoc 1.75 inch heavy-duty stainless steel tripod (7kg)
  • Optional WiFi for mount control via SmartPhone/Tablet/Computer

Go2Nova Hand Controller 8407

  • 200,000+ object database
  • 8 line, 21 character back lit large screen LCD
  • Low temperature operation as low as -20ºC
  • User friendly interface
  • 9 speed slew control with quiet mode
  • Large object database
  • Serial port for firmware upgrade

What's in the box

  • iOptron® CEM40 Mount Head
  • Hard Case
  • Go2Nova® 8407 Hand Controller
  • One 5kg / 11lbs counterweight
  • Stainless steel counterweight shaft
  • Internal iPolar electronic polar scope
  • AC adapter (100V-240V)
  • 2x coiled control Cable (6P6C RJ11 to RJ11, straight wired)
  • Serial cable (RS232 to RJ9)
  • USB cable
  • LiteRoc 1.75" tripod with improved stability and leg locks
  • Quick Start Guide


Mount Center-Balanced Equatorial Mount
Max payload* 40 lb (18 kg), exclude counterweight
Mount weight 17.4 lb (7.9 kg)
Payload/Mount weight 2.28
Structure Material All metal, CNC machined
Exterior Finish Anodised red/black
Latitude adjustment range 0º ~ 60º(special CW shaft mounting if <10° )
Azimuth adjustment range ± 6º
Tracking accuracy (PE)** <±7 arcsec
Period 400 sec
Worm diameter Φ17mm, Brass
Right Ascension worm wheel Φ110mm, 216 teeth, zero backlash
Declination worm wheel Φ110mm, 216 teeth, zero backlash
Right Ascension axis shaft Φ45mm steel
Declination axis shaft Φ45mm steel
Right Ascension bearings Φ68mm
Declination bearings Φ68mm
Counterweight shaft Φ28x280 mm, Stainless Steel (1.2 kg)
Counterweight 11lbs (5kg) x1
Motor Precision stepper motor, 1.8º/128X micro-step
Motor resolution 0.08 arcsec (200 PPS)
Transmission Synchronous belt
Hand Controller Go2Nova® 8407+, 8 line 21 character LCD
Star Database 212,000+, star identification
Power DC 12V, 5A (5.5mm/ 2.5mm plug)
AC adapter 100V ~ 240V (included)
Power consumption 0.6A(Tracking), 0.9A(GOTO)
Power-down memory Yes
Polar scope Internal iPolar TM electronic polar scope
Meridian treatment Stop (0-10° pass), flip
Zero position Automatic zero search
Dovetail saddle 8" Losmandy D & Vixen
Max slew speed 4.5°/sec (1080x)
Guiding scope/camera Built in guiding scope and camera, iGuiderTM
Guiding port ST-4
Communication port USB
WiFi External (optional)
Cable Management DC12V (3A), ST4,USB
Tripod LiteRoc 1.75" Stainless Steel (7kg)
optional tri-pier
Hard case Optional
Operation temperature -10ºC ~ 40ºC
Warranty Two year limited

* OTA size and length dependent

** Measured with encoder, 400 seconds

Downloads / Manuals


Quick Start Guide
Instruction Manual
iPolar Operation Manual


CEM40 Firmware
iPolar Software
FTDI VCP Driver, or go to FTDI Chip website to download the VCP driver

iOptron Telescope ASCOM Driver:

Install ASCOM Driver and Commander
iGuider ASCOM Driver

Customer reviews

Average Rating (1 Review):  
Write a Review and share your opinions!

Rating (max 5):  
Amazing bit of kit
28 February 2021  | 

First off fast and easy delivery from first light optics as usual well packaged and not very bulky in terms of boxes delivered

Its a compact mount that comes with a lovey protective flight case the product itself is very clean and well engineered you can sense and feel the quality as you take it out.
Being in the UK there are some small adjustment to be made setting the correct latitude is a simple task with the Alan keys provided a bit of bolt placement swapping.

I liked the idea that everything was self contained in this system with the iPolar and iGuider built in less wires and hassle with aliment of a guide riding on the OTA ect. iPolar works fantastic and i got aliment quickly but the provide USB lead seems cheap easily disconnects and drops out if you touch it so order a better quality lead with gold plated connections and this problem is no more!

one reason for the 4 star and not 5 is in part down to that cheap USB lead but that's a its a simple fix but how hard it was to get the iGuider focused this is less then fun and at one point thought maybe i had driver problems or something, in PHD2 i would get a lot of lines and noise but a day test showed me it was working fine when i focus on a car so now i knew everything driver wise was working correctly

Its more of a PHD2 thing if the guide camera isn't in focus it goes a bit crazy

best way around this is to use the moon to focused first as its a nice big object once that's focused you should be fine with picking up stars.

I bring this up because the focus adjustment thumb screw on this mount is very hard to use it slides back and forth with no resistance so getting the sweet spot for PHD2 to stabilise is a nightmare but a lot easier with the moon

other then that its been an incredible mount and look forward to spending some good years with it


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