Anycubic Kobra 2 3D printer review: The perfect first layer thanks to LeviQ 2.0

A large part of the specifications of the Anycubic Kobra 2 were taken directly from the predecessor, so most of the changes to the device are not evident from our spec sheet. On the motherboard, a Type-C socket has replaced the USB-B socket. The X and Y axes no longer run on Delrin rollers but on ball bearings. The Z-axis is now driven on both sides and has spring bearings. The two most noticeable changes to the 3D printer are probably the new print head and the filament roll holder adopted from the Anycubic Kobra Max. Unfortunately, the latter also drastically increases the 3D printer's space requirements. A whole 30 cm more width has to be planned for the new Kobra 2 in operation.

The design of the 3D printer thus remains stable and mostly angular. One exception in our case was the mounting bracket of the Nema 17 stepper motor on the back of the 3D printer. This was slightly bent in our test device. As a result, the drive belt of the Y-axis could not be tensioned properly and kept slipping against the limit of the drive wheel. The fault, which could also be a small transport damage, could be fixed. To do this, we completely relaxed the belt and then bent the angles back to 90°.

Unfortunately, nothing significant has changed in Cobra's cable management either. However, the new filament roll holder now makes the situation worse. No matter how you mount it, the cable harness to the extruder always drags on the filament, on the filament roll, or directly on the holder. All in all, the two moving cable harnesses come into contact with fixed components too often here.

The Trigroilla Pro board can be seen here in version B. It is a proprietary development by Anycubic and unfortunately only offers a few upgrade options due to many proprietary connections.
The actual innovation here is a USB-C connection.

An HDSC hc32f460 is used as the microcontroller on the board. The 32-bit chip with a Cortex M4 core runs at 200 MHz. Thus, Anycubic Kobra 2 has sufficient computing power.

Disappointingly, we have to note that Anycubic still does not equip all cable ends with cable lugs. Two of the strands are still tinned. Over time, the solder can flow and thus weaken the electrical connection.

For shipping, the 3D printer is disassembled into four assemblies. The full assembly is not very difficult: a total of eleven screws have to be screwed in. The necessary Allen keys and other tools are provided by Anycubic. Lastly, using the AnchorMake M5, we saw how easy the assembly of a 3D printer can be when the manufacturer provides the packaging as an assembly aid. That is not the case with Anycubic. Here, especially the mounting of the archway is a bit tricky. The long screws must somehow be screwed in from below. To do this, the base can be tilted or placed over the edge of the table. Another difficulty is that on the left side of the printer, a cable harness partially covers the hole for a screw. Once the sheet is mounted, the screen and print head are attached to the appropriate locations. All cables are labeled, so assigning them to the appropriate sockets is not difficult. The complete assembly took us about 20 minutes.

After assembly, the Anycubic Kobra 2 can be put into operation immediately. There are already four print-ready files on the SD card. There is also a copy of Prusa Slicer 2.5 and a corresponding configuration file on the SD card. Before the first print, however, the bed-leveling program should be run. Using an induction sensor and nozzle sensor, the Kobra 2 determines the distance between the nozzle and the print bed over the entire surface completely independently. Manual adjustment of the 220 x 220 mm print area is neither necessary nor possible.

We decided to first print a classic 3D-benchy directly from the supplied files. The bottom of the finished object here shows that the auto-leveling results were not quite perfect. Before the next print, we reduced the nozzle distance by 0.05 mm in Kobra 2's menu.

Anycubic raises high expectations with the advertising promise of 250 mm/s. In the practical test, 150 mm/s seems more realistic. While the powerful combination of the extruder and hotend can convey enough plastic to achieve even more than 250 mm/s, it is the motion system that limits the speed here. Even at Anycubic's recommended 150 mm/s, the print results show clear signs of too high a speed. In addition, the settings of the Cobra 2 actually provide for relatively low accelerations of 2,500 mm/s. To achieve 250 mm/s at this acceleration value, there would have to be straight lines at least 50 mm long. Nevertheless, the 3D printer produces objects of more than acceptable quality.

The print bed of the Anycubic Kobra 2 also consists of a multilayer structure. The base here is an aluminum plate that is approximally 2 mm thick. This is heated from the underside. On the upper side a magnetic foil is glued almost over the entire surface. The magnetic printing plate made of PEI-coated spring steel is applied to this. The PEI coating is heavily roughened and ensures good adhesion. However, the prerequisite is that the surface is clean and free of grease and has been heated above the glass transition temperature of the filament. Since PEI is very resistant to chemicals, caustic soda, acetone, or alcohol can also be used for cleaning.
The print bed is not insulated on the underside. This can be retrofitted with little effort; without insulation, the 3D printer consumes more power, and the print bed exhibits more temperature differences. The thermal image shows temperatures between 53.6 °C and 58.4 °C at a target temperature of 60 °C on the test device. At a room temperature of 22.6 °C, the cable harness to the print bed heats up to 34.6 °C. The low heating is evidence of a well-chosen cable cross-section to the print bed. The cable has to transmit up to 400 watts. The operating temperature of 60 °C for printing PLA is thus reached within about 100 seconds. At most, the print bed can be heated up to 110 °C. This takes more than 5 minutes.

In the practice of 3D printing, a good first layer often determines the success or failure of a 3D print more than anything else. With LeviQ 2.0, the Anycubic Kobra 2 takes another step away from the user to set up the 3D printer optimally. As we found in testing, this process also needs to be set up by the user first, however, it is only a single step that ensures a perfect result here. After setting up the 3D printer, it is important to set the position of the sensor correctly in the firmware. If the filament nozzle hits the sensor exactly in the middle, the results of LeviQ 2.0 will be almost perfect. We did not pay attention to this at the beginning, which meant that the nozzle distance to the print bed was too large in the first 3DBenchy and too small in the Notebookcheck FDM test. Only towards the end of the test period did we become aware of this error.

LeviQ 2.0 measures the print bed with an inductive proximity sensor at 25 points. The nozzle is then heated up on the extruder, cleaned on the silicone pad, and also measured. The end user only has to start the process via the menu on the touchscreen, and the Anycubic Kobra 2 does the rest on its own. The process takes about five minutes.

As always, we tried to trigger all possible temperature errors with this printer. The Anycubic Kobra 2 responded reliably to all scenarios. Whether a temperature sensor was disconnected, shorted, or deviated too much from the expected values, the 3D printer consistently shut down all heating elements. This is an essential safety feature that can prevent damage to the 3D printer and, in the worst case, fires. The fact that the Anycubic Kobra 2 does not trigger an audible alarm in case of temperature deviations is perhaps the only point of criticism. Only an error message is displayed.

As we also criticized with the AnkerMake M5, the maximum temperature of hotends with PTFE inliner should not exceed 250 °C. On the Anycubic Kobra 2, up to 260 °C can be set. PTFE, better known under the brand name Teflon, can outgas toxic fumes at a temperature above 260 °C.

The now continuous protective conductor also contributes to safety. All metal parts of the Kobra 2 are connected to the protective conductor. To this end, Anycubic has in some cases pulled additional cables through the wiring harness to the extruder.

However, we are missing a step when it comes to protection against jamming on moving components. The drive wheel of the Y-axis could be provided with a cover here to further increase the safety of the 3D printer. In principle, however, you should also keep in mind that there are also many other sources of danger with the open design of the Anycubic Kobra 2. For example, pickled and moving components are always easily accessible. The possibly harmful vapors from heated plastic can also spread around the room.

Up to 59 dB(A) was measured with the Voltcraft SL10 sound level meter at a distance of one meter from the 3D printer during operation. Together with the strong vibrations at the maximum speed of the printer, this value rises to up to 72 dB(A). The object fan in the print head makes a large contribution to normal operating noise. To reduce the operating noise, the fan can be throttled down or switched off completely in certain situations. Prusa Slicer is able to control the fan depending on the situation. It is thus possible to reduce the minimum fan speed from 100% to a lower value. This not only makes the printer quieter but also reduces power consumption. A large part of the energy required for 3D printing is used for heating and reheating the print bed. The less air circulating above the print bed, the lower the energy consumption.
The open design also disperses odors and vapors from the melted plastics throughout the room. Depending on which plastics are processed with the 3D printer, the vapors can smell unpleasant or even be harmful to health.

A completely new print head, new guide rails on the X and Y axes, and the new Anycubic LeviQ 2.0 bed leveling are the three most important upgrades from the Anycubic Kobra to the Kobra 2. This makes the 3D printer somewhat faster but above all more convenient to operate. Readjusting the bed leveling is no longer necessary. This should be an interesting innovation for beginners because a 3D print stands and falls with a good first print layer. At the time of this review's completion, there are still a few days until the Kobra 2's market launch. Anycubic should use these to improve the last fine adjustments. Then the Cobra 2 could become a price-performance tip. At around 300 Euros, the 3D printer is affordable.

However, the same points of criticism that we have seen in all Kobra 3D printers so far stand out negatively. Only mediocre cable management, tinned cables, and only a few control options via the touchscreen. With the Kobra 2, the impression of poor cable management has intensified in combination with the new filament roll holder.

Compared to the predecessor model, Anycubic has made detail improvements in the Kobra 2, but they have a big impact on the usability of the 3D printer. Longer maintenance intervals and faster setup, even for 3D printing novices, are to be expected.

When it comes to maintenance in particular, Anycubic's new 3D printer should require significantly less effort than its predecessors. Instead of Delrin rollers that wear out quickly, SG15 ball bearings combined with silver steel axles are much easier to clean and more durable. As long as the axles are regularly dusted and oiled, maintenance should be minimal. Switching from Ultimaker Cura to Prusa Slicer, on the other hand, is certainly not an easy step for every user. However, the results of both programs are equivalent.

In the end, the 3D printer hardly differs from competitors like Anycubic Kobra, Artillery Genius Pro, or VoxeLab Aquila. It is the details that distinguish the 3D printers from each other. Meanwhile, the performance spectrum of modern 3D printers is very similar.