Encoded consumable materials and sensor assemblies for use in additive manufacturing systems

An encoded filament for use in an additive manufacturing system having an extrusion head, the encoded consumable filament comprising:

• compositionally, a consumable polymer based material;
• a longitudinal length comprising a varying cross-sectional geometry;
• volume-increment markings that are spaced apart at varying distances along the longitudinal length of the encoded filament to define a plurality of segments of the encoded filament, wherein the plurality of segments of the encoded filament comprise:
• a first segment having a first increment length and a first volume;
• and
• a second segment having a second increment length and a second volume, wherein the first increment length is different from the second increment length, and the first volume is substantially the same as the second volume;
• wherein the volume-increment markings are configured to be read by an optical sensor of the additive manufacturing system;
• and
• the cross-sectional geometry configured to be received by a liquefier of the extrusion head for building a three-dimensional model from the consumable material.

A method for manufacturing an encoded filament for use in building a three-dimensional model with an additive manufacturing system, the method comprising:

• providing a filament compositionally comprising a consumable polymer based material, and having a longitudinal length and a cross-sectional geometry configured to be received by a liquefier of an extrusion head retained by the additive manufacturing system for building he three-dimensional model from the consumable material;
• moving the filament at a predetermined line speed;
• measuring cross-sectional dimensions along the longitudinal length of the moving filament;
• and
• forming volume-increment markings spaced apart along the longitudinal length on the moving filament by varying marking phase timings in response to the measured cross-sectional dimensions such that segments of the filament between each successively formed volume-increment marking have substantially the volume and, wherein at least a portion of the segments of the filament having substantially the same volume also have different increment lengths.