Coldrunner

Coldrunner is a term used in the context of 3D printing, specifically in Fused Deposition Modeling (FDM) technology. It refers to a phenomenon that occurs when the extruder of a 3D printer moves without extruding material, often resulting in a visible gap or defect in the printed object. This can happen due to several reasons, including issues with the filament, extruder, or the printer's settings.

The term "coldrunner" is borrowed from traditional manufacturing processes, where it refers to channels in a mold through which molten material flows to reach the cavity where the part is formed. In the context of 3D printing, the term is used metaphorically to describe the lack of material flow when the extruder is supposed to be depositing filament.

Coldrunners can lead to weak points in the printed object, affecting its structural integrity and aesthetic appeal. To mitigate this issue, users can adjust the printer's settings, such as the extrusion temperature, print speed, or retraction settings. Ensuring the filament is of high quality and the extruder is functioning properly can also help prevent coldrunners. Regular maintenance and calibration of the 3D printer can further reduce the likelihood of this issue occurring.