VOLUMETRIC FEED CONTROL FOR FLEXIBLE FILAMENT

摘要

A volumetric feed control apparatus (10) for a build material element such as a filament (20) used in a three-dimensional modeling machine (12) having an application tip (17) includes a pair of feed rollers (14) feeding the filament (20) to the application tip (17), and a sensor or sensor system (23) feeding information to a central processing unit (74) that continuously computes the effective cross section of the filament (20) using the signals received from the sensor or sensor system (23). The central processing unit (74) controls the speed of a DC servo or stepper motor (24) which in turn rotates the feed rollers (14) to advance the filament (20) toward the application tip (17) of the modeling machine (12). The central processing unit (74) adjusts the speed of the feed rollers (14) to supply a constant flow of material to the application tip (17). Alternatively, the sensor system (23) can be incorporated into the feed rollers (14), eliminating the need for further space constraints.