The C402A1 is the CEM40 package for the observer or imager who expects the mount to travel. You get the same 40 lb (18 kg) CEM40 head, internal iPolar, 5 kg counterweight, and fitted hard case, but the support is iOptron's lighter 1.5-inch stainless-steel tripod rather than the heavier 1.75-inch LiteRoc.
The result is a complete equatorial mount system that is easier to move from the house to the yard, load into a vehicle for a star party, or pack for a longer trip. The mount head weighs just 17.4 lb (7.9 kg), the tripod about 11 lb (5 kg), and each major piece travels separately instead of becoming one large, awkward load.
You are not giving up CEM40 capability to get there. The mount still carries up to 40 lb of telescope and imaging equipment, excluding counterweights, with internal iPolar, Permanent Periodic Error Correction, GPS, automatic zero-position sensing, and a 6-inch dual saddle for Losmandy D and Vixen-style dovetails.
Key Features
-
Travel-oriented CEM40 package. Includes the mount head, 1.5-inch stainless-steel tripod, 5 kg counterweight, internal iPolar, hand controller, and fitted hard case.
-
40 lb payload capacity. iOptron rates the CEM40 for up to 18 kg (40 lb) of telescope and imaging equipment, excluding counterweights.
-
17.4 lb mount head. At 7.9 kg, the CEM40 provides substantial imaging capacity without requiring a heavy head.
-
1.5-inch stainless-steel tripod. The included tripod weighs approximately 11 lb (5 kg), about 4.4 lb (2 kg) less than iOptron's 1.75-inch LiteRoc.
-
Hard carrying case included. Protects the mount head during storage and transportation.
-
5 kg counterweight included. One 11 lb counterweight is supplied for the 28mm stainless-steel counterweight shaft.
-
Center-Balanced Equatorial design. iOptron's CEM layout places more of the combined mount and payload mass directly over the tripod.
-
Internal iPolar electronic polar scope. Camera-based polar alignment is built directly into the RA axis.
-
Periodic error below ±7.5 arcseconds. iOptron specifies native PE below ±7.5 arcseconds over the mount's 400-second worm period.
-
Permanent Periodic Error Correction. A trained correction can be stored in the mount to reduce the repeating component of RA tracking error.
-
Belt-driven worm system. Both axes use 110mm diameter, 216-tooth worm wheels driven by 17mm brass worms through synchronous belts.
-
45mm steel axles and 68mm bearings. Substantial internal components for a mount head weighing less than 18 pounds.
-
Precision stepper motors. 128 micro-steps provide a specified motor resolution of 0.08 arcsecond.
-
Up to 4.5°/sec slewing. Maximum GoTo speed is approximately 1080× sidereal.
-
Go2Nova 8410 hand controller. Provides an 8-line × 21-character display, built-in heater, and a database of more than 212,000 objects.
-
Built-in 32-channel GPS. Supplies time and location information when the mount arrives at a new observing site.
-
Automatic zero-position search. The mount can electronically locate its mechanical reference position.
-
Power-down memory. Positional information can be retained after a normal power-down.
-
Configurable meridian treatment. The mount can stop or flip, with settings allowing up to 10° of travel past the meridian when clearance permits.
-
6-inch dual saddle. Accepts both Losmandy D and Vixen-style dovetail plates.
-
Through-mount connections. A 12V DC output rated to 3A, ST-4 guide connection, and USB are routed through the mount.
-
Optional Wi-Fi. iOptron's external iStarFi adapter can add wireless mount control.
- Two-year limited warranty.
Why Choose the 1.5-Inch Tripod Package?
iOptron offers the CEM40 with more than one support option because portability and maximum rigidity are not always the same priority.
The 1.5-inch stainless-steel tripod included here weighs approximately 5 kg (11 lb). The 1.75-inch LiteRoc supplied with the C402A3 weighs approximately 7 kg (15.4 lb). That difference of about 4.4 pounds may not sound dramatic on paper, but it is noticeable when every component has to be carried from the vehicle to an observing site.
The important point is that the mount head itself is unchanged. This is still the 40 lb-capacity CEM40. The lighter tripod simply makes this package the more transportable choice.
If your system is particularly long, heavy, exposed to wind, or normally stays close to home, the additional mass of the 1.75-inch LiteRoc may be worthwhile. If you regularly move the system and value keeping each component manageable, the 1.5-inch package has an obvious advantage.
A 40-Pound Mount Head You Can Actually Carry
The CEM40's payload-to-head-weight ratio is especially useful when the mount travels.
The head itself weighs only 17.4 lb, yet iOptron rates it for up to 40 lb of telescope and imaging equipment. Cameras, filter wheels, electronic focusers, guide equipment, rotators, rings, dovetails, and cabling all count toward that payload, so having capacity beyond the optical tube alone gives you room to build a complete system.
Payload weight is not the entire story. Tube length, diameter, center of gravity, wind exposure, focal length, and image scale all affect how demanding a telescope will be on a mount. A compact system and a long refractor of identical weight do not necessarily behave the same way.
But the basic attraction remains: the CEM40 gives you serious equatorial-mount capacity without asking you to transport a 30- or 40-pound mount head.
iPolar for a Mount That Changes Locations
A portable equatorial mount has to be polar aligned every time it arrives at a new observing site, which makes the CEM40's internal iPolar especially useful in this package.
Instead of looking through a traditional polar scope and positioning a star on a reticle, iPolar photographs the surrounding polar sky and plate-solves the field. The software determines where the mount's RA axis is pointing relative to the celestial pole and shows you how to adjust the altitude and azimuth controls.
Polaris itself does not have to be visible. The iPolar camera still needs enough surrounding polar sky to solve successfully, but you do not need to identify or manually position the pole star.
Built-in GPS supplies the mount with time and location information after you move to a new site, while automatic zero-position sensing gives it a repeatable mechanical reference.
Tracking and Guiding
The standard CEM40 uses a precision worm drive rather than a high-resolution tracking encoder.
Both RA and DEC use 110mm diameter, 216-tooth worm wheels driven by 17mm brass worms through synchronous belts. The RA worm completes one cycle every 400 seconds, and iOptron specifies native periodic error below ±7.5 arcseconds.
Permanent Periodic Error Correction allows the mount to store a correction for the repeating component of that RA worm error.
For demanding long-exposure astrophotography, particularly as focal length and image scale increase, conventional autoguiding remains the normal approach. If you specifically want a high-resolution RA encoder and Real-Time Periodic Error Correction, the CEM40EC is the corresponding step up.
Connections in the Field
The CEM40 includes a straightforward through-mount cable-management system.
A 12V DC output rated to 3A, an ST-4 guide connection, and USB are routed through the mount so those particular cables do not have to cross the moving axes externally.
This is a USB pass-through rather than a multi-port imaging hub. A more complicated imaging train may still use a small hub or mini computer mounted near the telescope.
The mount itself communicates with a computer through USB. Built-in Wi-Fi is not included, but iOptron's optional iStarFi adapter can add wireless mount communication.
What Owners Say on Cloudy Nights
Travel with a conventional equatorial mount always involves some planning, especially when a tripod and counterweight are part of the system. But CEM40 owners do take these mounts on the road.
"Went to Nevada last month with my CEM40. Put the head in the case and packed inside a suit case."
That Cloudy Nights owner used a lighter carbon-fiber tripod rather than the standard iOptron tripod and packed the counterweight separately. The useful takeaway is not that there is one correct way to fly with a CEM40, but that the relatively light head and separate hard case make the mount realistic to transport.
The same discussion also shows why airline travel should be planned around the carrier rather than assumed from the dimensions of the equipment. Carry-on and checked-baggage limits vary by airline, aircraft, route, and fare, and heavy counterweights deserve particular attention when planning baggage.
For automobile travel, the division into a 17.4 lb head, 11 lb tripod, separate counterweight, and telescope makes the system much easier to load and move than one large assembled mount.
Under Dark Skies
The reason to move an imaging mount at all is what happens when you put it under a sky worth traveling for.
A short refractor or camera lens can take advantage of the enormous structures that become difficult from brighter suburban skies: the Rho Ophiuchi complex around Antares, the dark lanes of the Pipe Nebula, the North America and Pelican Nebulae, or the sprawling dust and emission regions running through Cygnus.
Add more focal length and the same CEM40 can carry a substantially more ambitious imaging system. The mount is not limited to a particular type of travel telescope simply because this package uses the lighter tripod.
That is really the appeal of the C402A1: you can take a full CEM40 platform with you instead of stepping down to a much smaller mount simply because the observing site is away from home.
What's Included
- 1x iOptron CEM40 Center-Balanced Equatorial mount head
- 1x Internal iPolar electronic polar scope
- 1x 6-inch Losmandy D / Vixen dual saddle
- 1x Go2Nova 8410 hand controller with built-in heater
- 1x iOptron 1.5-inch stainless-steel tripod, approximately 5 kg (11 lb)
- 1x 5 kg (11 lb) counterweight
- 1x 28mm × 280mm stainless-steel counterweight shaft
- 1x Fitted hard carrying case for the mount head
- 1x 100–240V AC adapter for indoor use
- Mount connection accessories
Frequently Asked Questions
What is special about the C402A1 package?
It combines the CEM40 with iOptron's lighter 1.5-inch stainless-steel tripod, one 5 kg counterweight, and a fitted hard case for the mount head. It is the more transport-oriented CEM40 package.
How much does the tripod weigh?
iOptron lists the 1.5-inch stainless-steel tripod at approximately 5 kg (11 lb).
How does that compare with the 1.75-inch LiteRoc?
The 1.75-inch LiteRoc supplied with the C402A3 weighs approximately 7 kg (15.4 lb), making it about 4.4 lb (2 kg) heavier than the 1.5-inch tripod.
Does using the 1.5-inch tripod change the CEM40's payload rating?
The mount itself retains iOptron's published 40 lb payload rating. As with any telescope mount, tube geometry, wind, center of gravity, focal length, and the rigidity of the complete support system should also be considered.
Should I choose the 1.5-inch tripod or the 1.75-inch LiteRoc?
Choose the 1.5-inch package when easier transportation is a priority. Choose the heavier 1.75-inch LiteRoc when additional support mass is more important than saving roughly 4.4 pounds of tripod weight.
Does this package include a hard case?
Yes. A fitted hard case for the CEM40 mount head is included.
Does it include a counterweight?
Yes. One 5 kg (11 lb) counterweight is included. Depending on the complete telescope system, additional counterweight may be required for proper balance.
Can I fly with the CEM40?
CEM40 owners do travel by air with their mounts, but there is no universal airline packing rule. Baggage dimensions, weight limits, carry-on allowances, and security requirements vary, so check the current rules for your airline and itinerary before traveling.
Does the CEM40 include iPolar?
Yes. Internal iPolar is installed in the RA axis.
Does iPolar require Polaris to be visible?
No. Polaris itself does not have to be visible, although enough surrounding polar sky must remain unobstructed for the camera to plate-solve successfully.
Does the CEM40 need guiding?
For demanding long-exposure astrophotography, particularly at longer focal lengths, guiding is the normal approach. The standard CEM40 uses PPEC but does not have the high-resolution RA encoder of the CEM40EC.
Can I upgrade the tripod later?
Yes. A 1.75-inch LiteRoc or an appropriate Tri-Pier can be used when you want a more substantial support.
Accessories
iOptron 1.75-inch LiteRoc Tripod (sold separately): a more substantial portable support when additional tripod mass is preferred.
iOptron 2.5 kg #8027-05 Counterweight (sold separately): useful when the complete telescope system requires more counterweight than the included 5 kg weight provides.
iOptron Tripod Carry Bag (sold separately): gives the 1.5-inch tripod its own bag for transportation and storage.
iOptron iStarFi Wi-Fi Adapter (sold separately): adds wireless mount communication.
Final Thoughts
The C402A1 makes sense when you want to travel with a CEM40 without giving up the CEM40 itself.
You still get 40 lb of payload capacity on a 17.4 lb head, internal iPolar, PPEC, GPS, automatic zero search, through-mount connections, and the dual saddle. The difference is underneath it: the 1.5-inch stainless-steel tripod weighs about 4.4 pounds less than the 1.75-inch LiteRoc.
The included hard case protects the head, while the tripod, counterweight, telescope, and mount remain separate pieces that can be packed and carried individually.
If maximum portability matters more to you than having the heavier tripod, this is the CEM40 package built around that priority.
