To start, Marlin 2 has revamped its thermal settings, improving on Marlin 1’s thermal control system.

• Greater heated chamber support: This is one area where Marlin 1 was notably lacking. These new support features are very beneficial for anyone printing with ABS or ASA, which strongly benefit from a heated chamber.
• Improved bed temperature control: To keep your bed temperature from overheating, you’ll be glad Marlin 2 has improved Marlin 1’s limited thermal compensation abilities. This feature allows your 3D printer to have a “smart-heating system”, where bed heating is raised or lowered to prevent drifting from the provided setting.
• Improved nozzle temperature control: Marlin 1 has great temperature settings for 3D printers but, according to users, sometimes fails to control the hot end temperature, causing it to go too high. This can lead to a stopped print or a damaged nozzle. Marlin 2 addresses this problem.

Next on the list of changes is all things mechanical.

• Improved linear advance settings: Compared to Marlin 1, Marlin 2 allows for more accurate extrusion and fewer over- and under-extrusion issues.
• Greater fan control: Marlin 1 was very limited in its fan control options. Addressing the importance of airflow during printing, you’ll be happier with Marlin 2’s capabilities.
• More accurate Z probe offset: By adding more decimal places to Marlin 1’s setting, Marlin 2 offers more precision with the Z-axis offset, leading to better print quality.
• Greater precision for hot end offsets: Similar to the Z offset, this upgrade makes the motion and placement of the hot end more exact.

When dealing with high voltages and high temperatures, safety comes first! To keep 3D printers from destroying themselves or anything else, Marlin 2 has improved its safety features and fail-safes compared to the previous version.

• Improved thermal runaway control: This will prevent your 3D printer from getting too hot, which could occur with Marlin 1’s firmware.
• Additional heating chamber protection: This is a welcome new feature of Marlin 2.
• Improved print stopping safety: To prevent the printer from destroying itself with the print, the stop safety has been upgraded.

In the area of overall usability, Marlin 2 also proves itself to be a worthy upgrade.

• Better translations: By updating the translation of Russian, German, and Italian, there’s no need to worry that messages and buttons are mislabeled or incorrectly translated, which have been known to cause errors.
• Transparency of EEPROM errors: EEPROM is the memory stored in the mainboard itself. If you save your custom settings to the EEPROM and there’s an error, not knowing this could cause all of your settings to be lost. Users found that Marlin 1 didn’t show the EEPROM errors, so Marlin 2 has updated this.
• Improved use of the M240 command (photo trigger): This will significantly improve OctoPrint‘s Octolapse and regular time-lapse in Marlin 2. Now you can get better images and videos of your prints!

Naturally, Marlin 2 isn’t quite as stable as the well-established Marlin 1. But over time, as more and more makers use the firmware and provide their feedback, we can expect Marlin 2 to become just as reliable as its predecessor.

An expansion of supported hardware makes Marlin 2 very flexible. As it continues to develop and new versions are released, we’re expecting even more compatibility options in the future.

• More hardware support: Marlin 1 had a good amount of supported hardware, such as proximity bed leveling sensors, hot ends, and heating units. Now, Marlin 2 has greatly expanded that list, adding compatibility to new mainboards, LCD and touchscreen displays, temperature sensors, hot ends, bed leveling sensors (like the BLTouch V3), and more! Additionally, it’s added many more compatible printers, upgrades, and other technology.

Despite all the improvements, Marlin 2 does have one large issue: memory consumption. When using Marlin 1, an 8-bit board’s memory allows for use of SD card support, auto-bed leveling, BLTouch support, and power loss recovery.

With Marlin 2, if you’re using an 8-bit board with the standard 128 KB of memory, you’re likely to run out. (Many standard printers, including the Ender 3, come with this board.) To enjoy all of Marlin 2’s features with an 8-bit board, you might have to disable SD card support and print on other platforms, like OctoPrint.

This fact leads many Marlin 2 users to consider upgrading to a 32-bit board with the standard 256 KB of memory. At the same time, there are some users who report that running Marlin 2 on an 8-bit board works fine; it’ll just depend on your printer and board.

If the potential memory issue isn’t immediately outweighed by the many improvements for you, know that the situation will only get better. As the 3D printing community moves towards using Marlin 2 exclusively, we’re sure that it’ll have more features and improvements as well as greater stability.

In the end, it’s undeniable that Marlin 2 offers better features than Marlin 1. However, if your printer’s mainboard can’t handle all of these new features and you don’t want to upgrade, you might want to stick to Marlin 1 until a less memory-consuming version comes out. Either way, the Marlin community is there to help you with any problems you might have.