3D printer firmware: what it is and what you see of it in a print

What firmware does

Firmware is the basic program of a device that starts by itself at power-up and looks after the hardware. In a 3D printer it reads the commands from the G-code created by the slicer, and decides how fast the motors move, when heating switches on and how precisely the temperature is held.

Well-known open source firmwares include Marlin and Klipper. Most manufacturers now ship their own version built on something like that, with added control through a screen and an app.

What firmware changes on a print

Firmware does not work miracles, but it sets how well the printer handles what the slicer sends it. Well-tuned firmware holds a stable temperature, accelerates and brakes smoothly, compensates for vibration and can handle a power cut or running out of filament.

You can tell by things a customer sees: cleaner corners without ripples, more even walls, fewer faults at colour changes. Poor tuning shows up as the opposite, for example ripples behind edges, known as ghosting, or an uneven flow of plastic.

Firmware also handles safety. If the temperature will not rise or drops sharply, it switches the heating off so the printer does not overheat. That is why a print sometimes stops when something unusual happens, even if the model is fine.

Updates and their risks

A firmware update can fix bugs and add features, but sometimes it changes how the printer behaves and the profiles need fine-tuning. That is why printers that need to run long and reliably are not updated blindly as soon as a new version comes out.

A bad or interrupted update can even lock up a printer, so you should read the manufacturer's notes first. Our printers are Elegoo Centauri Carbon 2, and we handle their setup.

What this means for your order

You do not have to set or know anything. Firmware belongs to the printer, not to the file you send us. What matters are model matters: model orientation, wall thickness and tolerances.

If an exact dimension matters to you, put it in the note with your order. Dimensions are affected by the material and the shape of the part, not only by the firmware, so we do not promise accuracy to a tenth of a millimetre. We photograph every batch before dispatch.