Printer for three dimensional printing

A printer for three dimensional printing comprising one or more extrusion cores;

• wherein each such extrusion core comprises structures surrounding an elongate-volume;
• wherein the elongate-volume removably receives a filament;
• wherein this elongate-volume defines and substantially bounds a filament-pathway, wherein the filament enters one-end of the elongate-volume as a solid and leaves a distal-end of the elongate-volume as a liquid;
• wherein said structures comprise:
• a hot-end that begins at the distal-end;
• wherein the hot-end comprises a first-temperature-controlled-block surrounding a portion of the elongate-volume;
• wherein this portion of the elongate-volume is a melt-chamber;
• a transition-section that begins where the hot-end ends;
• wherein the transition-section is disposed between the one-end and the distal-end;
• wherein the transition-section comprises a first-insulator and a second-temperature-controlled-block for heating the filament;
• wherein the transition-section surrounds a different portion of the elongate-volume;
• wherein the different portion of the elongate-volume comprises a diverging-converging-chamber that first diverges and then converges with respect to a direction from the one-end to the distal-end, wherein a widest portion of the diverging-converging-chamber is located at an interface between the first-insulator and the second-temperature-controlled-block;
• a cool-end that begins where the transition-section ends and wherein the cool-end ends at the one-end;
• wherein the cool-end comprises a second-insulator surrounding yet another different portion of the elongate-volume;
• wherein the first-temperature-controlled-block liquefies portions of the filament passing through the hot-end such that the distal-end discharges liquefied filament.

A printer for three dimensional printing comprising one or more extrusion cores;

• wherein each such extrusion core comprises structures surrounding a filament-pathway;
• wherein the filament-pathway removably receives a filament;
• wherein the filament enters one-end of the filament-pathway as a solid and leaves a distal-end of the filament-pathway as a liquid;
• wherein the filament-pathway comprises a diverging-converging-chamber;
• wherein with respect to a direction of flow of the filament through the filament-pathway from the one-end towards the distal-end, the diverging-converging-chamber begins at a first-cross-section-size of diverging-converging-chamber;
• wherein a cross-section of diverging-converging-chamber then progresses by increasing in size until a maximum-cross-section is reached;
• wherein the cross-section then decreases in size until terminating at a second-cross-section-size;
• wherein these cross-sections are substantially perpendicular to a longitude of the filament-pathway;
• wherein a portion of the diverging-converging-chamber is heated by a temperature-control-block and another different portion of the diverging-converging-chamber is not heated;
• wherein the diverging-converging-chamber minimizes interruptions in the direction of flow of the filament along the filament-pathway.