Glossary · Part

3D printing

Hotend

The heated part of the print head in which the plastic filament is melted.

Explained in more detail

Consists of a heater block, heater cartridge, temperature sensor, heatbreak and nozzle. The heatbreak separates the hot zone from the cold zone so that the filament does not soften too early. The maximum temperature limits the choice of material: PLA needs around 200 °C, PETG 240 °C, ABS and ASA 240 to 260 °C, PC and PA often 250 to 300 °C, and high-performance plastics such as PEEK roughly 370 to 450 °C depending on the filament. For fast printing, the maximum volumetric flow rate in mm³/s is the most important figure.

Where does the term come from?

From English: hot end means "heißes Ende". It refers to the part of the filament path where melting takes place. The cold part with the drive is correspondingly called the cold end.

In practice

• Classic standard hotends manage roughly 10 to 15 mm³/s, current hotends on fast printers about 20 to 30 mm³/s.
• Before printing PA or PC, check the maximum temperature of your hotend: depending on the type, these materials need 250 to 300 °C.
• The heat sink above the heatbreak needs a fan that runs as soon as the hotend is hot. If it fails, the hotend clogs quickly.
• The hotend gets hotter than 200 °C: when working on it, use gloves or tongs and follow the manufacturer's instructions.

Not to be confused

The hotend is not the extruder: the extruder feeds the filament, the hotend melts it. In everyday speech the whole print head is still often called the extruder.

Frequently asked questions

What is an all-metal hotend?

A hotend in which the PTFE tube ends before the heatbreak, so that only metal is in the hot zone. This permits permanently higher temperatures, as required by ABS, PA or PC.

Why does my hotend clog with PLA?

Heat creep is often the cause: the filament softens above the melt zone and gets stuck. Typical triggers are a failed hotend fan or an enclosure that is too warm.