Bulldog type extruder

This project presents the design of a 3D-printed Bulldog-type extruder intended to replace the stock extruder of the Creality Ender 3 3D printer. The design is based on the well-known Bulldog extrusion mechanism, chosen for its compact form factor, high filament grip, and improved feeding consistency compared to the original plastic extruder. The model is conceived as a direct mechanical replacement, maintaining compatibility with the Ender 3 mounting system while aiming to enhance durability and extrusion reliability.

At the current stage of development, the design is functional in its main structure; however, the integration of the PTFE (Teflon) tube inlet and outlet is still pending and will be addressed in future iterations. Despite this, the extruder body has been successfully manufactured and evaluated as a proof of concept.

The prototype was 3D printed using a 1.0 mm nozzle, with a layer height of 0.25 mm, enabled supports, and an infill density of 8%. These printing parameters were selected to balance structural strength, material efficiency, and reduced printing time. The results demonstrate the feasibility of producing a robust Bulldog-style extruder through additive manufacturing, offering a low-cost and customizable alternative to commercial extruder upgrades for the Ender 3 platform.