For some theaters you need the biggest pranks – Živěcz

Over the past ten years, many 3D printers for DIYers and professionals have passed through our editorial staff. At the beginning of 2014, it must have been a little UP! Min. It printed fine, but then you paid some thirty thousand crowns for a production volume of 120 × 120 × 120 millimeters.

It’s no wonder that Josef Průša quickly established himself with his open and simple construction, and over time his line of i3 models has become one of the most successful 3D printers around twenty thousand crowns on the market. Marlet.

But predatory Asia, which competes mainly on price, is increasingly speaking out. At the end of this winter, our newsroom was heated by two machines Anycubic Cobra. The manufacturer officially presents them at the beginning of the week.

Cobra Max prints on glass

We came out of the first bulky box CobraMax ($649). As the name suggests, the main advantage will be the print volume, which is really respectable: 402 × 402 × 452 millimeters.

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Cobra Max and our reference prints. Details can be found in the gallery

In this case, the filament of the molten plastic is laid on carborundum glass plate. The surface is rougher and the model usually bounces back after removal.

Little Cobra prints on a grainy plate

In the second and a little smaller box she was waiting for us Cobra ($349) attributeless capable of handling print volume 222 × 222 × 252 millimeters and is equipped elastic grain plate for the printing plate.

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The smallest Cobra and still its reference prints

This makes it easier to peel off the finished model and thanks to the grainy pattern, the bottom layer will look like a mold – there will be hardly any signs of the individual fiber structure.

Both printers were partially assembled and we managed the final assembly with full color instructions within a quarter of an hour. Basically all you have to do is screw in the vertical Z axis, connect the data and power cables and you’re done.

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Cobra Max glass plate with thick sheet to easily peel off the printed model and flexible grain plate on the smaller Cobra which creates a nice bottom layer

Classic 0.4mm nozzle and 1.75mm bead

Although the two machines of the same name have a completely different design, the parameters of the interchangeable nozzle (diameter 0.4 mm, chord 1.75 mm) are the same. You can set it on fire 260°C.

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Cobra Max nozzle and slime print

The Cobra press plate can handle 110°Cwide and open construction Kobra Max, however, securely only 90°C. In any case, in both cases you can print both basic PLA and ABS, PETG, TPU and related materials that fit this temperature range.

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While the Kobra Max has an external string feeder in a clear plastic cover, the smaller Kobra in the second photo has everything in its head, similar to a printer from Průša.

25 point automatic calibration

And one more thing the two machines have in common. It does not miss automatic plan calibration (25 point matrix), print end string detection and of course also resume printing after a power outage.

He takes care of the control himself 4.3″ color LCD with touch layer and as printing software the free Cura from Ultimaker, for which you will find the microSD included printing profiles.

25-point accelerated video calibration:

Simple touch control

By the way, the control on the touch screen is really basic. You start the calibration here, adjust the height of the first layer (Z offset), of course there is a list of files on the microSD, temperature adjustment and parameter adjustment during the print itself (temperature , speed, cooling fan speed ). But this is the end.

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Adjust settings when printing on the touch screen

Personally, I would certainly appreciate at least the basic service menu with the possibility of resetting the configuration to factory settings. You can do all this with the help of yourself G-CODE, a textual instruction language that tells the printer what to do. It also stores the 3D model itself as a set of motion commands for the printer’s stepper motors.

G-CODE Raw Instructions Solve Problems

Anycubic is based on the G-CODE Marlin instruction set, so when looking at the referenced list of commands, use the M502, M500, and M501 instructions to reset memory, store it in permanent EEPROM, and check and reload from the EEPROM.

You simply create a text file on your computer reset.gcode with this content:

M502 ; Resetuj konfiguraci
M500 ; Uloz aktualni konfiguraci do EEPROM
M501 ; Nacti konfiguraci z EEPROM

You save it to a microSD and the printer literally you print.

Eureka, the printer will suddenly be in the default state. I had to create a similar assembly, especially on the base Cobra, where I was initially hampered by the Y axis, i.e. a stepper motor that controls the movement of the print bed forwards and backwards.

Due to the greater resistance of the board, it would sometimes confuse its starting position and then often reconfigure itself by sensing the resistance. We always reset everything to its default state.

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Tighten your belt on Kobra printers

In the end, I had to play with the tightening of the screws and the belt, which fortunately is very simple, because both Cobras have red swivels on the X and Y axes. faucets.

Cobra Max printed at number one right after unboxing

The case above illustrates one of the problems you may encounter when printing, which will easily confuse a beginner. 3D printing today is still a profession, and although today similar machines are armed with a lot of automatisms, everyone has to go through these childhood diseases…

And for the first few weeks, for example, swear what he bought and why it doesn’t work as easily and predictably as the company copier and the coffee maker in the kitchen.

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The large surface is also ideal for printing a large number of small models. Maybe these pigeons against my pigeons on my balcony

Except for this minor complication, however, both machines performed very well – by the way, the Kobra Max even performed for the former well. After taking out of the box, screw the Z axis and start the automatic aircraft calibration further worked without any other intervention and adjustment. It was not necessary to adjust the already mentioned Z-offset, i.e. to fine-tune the height of the nozzle relative to the glass plate.

I have to admit it’s my first time. I always reserve the first week for a quality setting, but Kobra Max printed fine as is without a single other bad word.

We printed from PLA and of course without supports

In terms of quality, I’ve tried both a stack of cheap PLA materials and PETG strings from Průša (at home I print on my MK3S+ basically only from PETG). Everything at one layer height, from rough draft (0.3mm) to relative detail (0.1mm to 1.5mm). Both Cobras gave it away with no noticeable issues or flaws.

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Examples of impressions on Kobra and Kobra Max. Other photos are available in the gallery

The layers were straight, uninterrupted and both machines gave longer overhangs. All this, of course, without the impression of supports / scaffolding, which I hate to burst, and that’s why I always prefer to go at a risk of several hours, How it will end up.

Speaking of those hours, Cobra, on average, puts fiber into gear 50-80mm/s. Of course, you can change the speed when designing in Cura and later also when printing to the screen, but this is a safe range with no risk of defects. Cobra Max gives on average a little more: 80-100mm/s and given its size, it is also necessary.

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By the way, the prints of the neon blue filament (Sunlu PLA, neon blue)

The huge print volume is tempting, but with every additional cubic centimeter the production time and of course the amount of material consumed increases dramatically, so larger prints with higher print quality can easily take dozens of hours.

100-200 watts when printing from PLA

The two machines in our newsroom roared day and night for several weeks and burned on average during production 120W (Cobra) and 250W (Cobra Max) electricity. This applies to PLA and printing at 190°C. For materials requiring higher melting temperatures, the power consumption will of course increase.

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Cobra Max heated glass at 60°C and reality according to the Flir thermal camera. Due to the printer’s open design and large surface area, it’s not that bad

Final summary? We knew the raw prices in advance and we publish the item before the official launch in the Anycubic e-shop. At the same time, additional charges may increase them. Little Cobra in raw terms for 7,800 crowns however, it should still fit under ten thousand crowns.

Cobra Max for (again in raw terms) 14,500 crowns then it will be an attraction for those for whom normal print volumes of around twenty centimeters are not enough. They are usually no longer common and beginner DIYers, so the price is still very attractive.

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And this is what the largest print area on the Kobra Max looks like in practice (402 x 402 mm)

After all, these forty centimeters in each of the axes are really addictive, and on a similar giant (Cobra Max is not the only one on the market, of course) you can already produce almost everything.

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