Automatic mechanical spool changer for 3-d printers

Abstract

An automatic mechanical spool changer for 3-D printers includes a filament guide and a pre-loading device. The input to the filament guide receives at least a primary filament from a primary spool and a secondary filament from a secondary spool. The output from the filament guide connects to an extruder, and the output from the filament guide sequentially and automatically provides the primary filament and then the secondary filament to the extruder. The pre-loading device exerts a pre-loaded force on the secondary filament during the extrusion of the primary filament. After the primary filament passes a predetermined location within the filament guide, the force exerted on the secondary filament threads the secondary filament through the output of the filament guide and into the extruder.

Dependencies are inferred from the claim text.