[{"id":326,"title":"Heated volumetric extrusion mechanism with co-axial Auger and Moineau pumps for 3D printing from plastic pellets","sha":"ae254dc0e368a1b2b87b4047109f9b59","user_id":null,"state":"published","body":"The higher cost and lower availability of the thermoplastic filaments -compared to pellets- make FDM 3D printers underutilized in developing countries.\r\nWe designed a solution to use easily sourced plastic pellets with precise volumetric control of the extrusion flow. This is done by a rotor made of a \"Moineau\" progressing cavity pump co-axially coupled with an Auger screw, both contained within a single heated stator.\r\nOur extrusion mechanism works as follows:\r\n1) plastic pellets/granules enter the Auger screw, they are melted by the heated stator and pushed forward by the rotation of the screw, entering the cavities of the Moineau pump;\r\n2) the plastic is transported by the progressing cavities of the Moineau pump, proportionally to the amount of its rotation, to the extrusion nozzle.\r\nTo our knowledge, this technology -already used in food and oil industries- has not been applied to 3D printers, the main issue being the need to keep the system at 200-300 C, suitable for melting.\r\nThe final goal is to build a pellet extruder compatible with commonly used RepRap 3D printers at a low cost. It must be made out of metal and it can be driven by a stepper motor through a geared reduction.","created_at":"2016-08-01T15:59:25.566Z","updated_at":"2016-08-02T06:00:40.875Z","zenodo_id":142687,"doi":"http://dx.doi.org/10.5281/zenodo.59241","subject":null,"tags":["3d printing","co-axial auger and moineau pumps"],"vote_count":0,"view_count":1,"score":0.1,"deleted":false,"muted":false,"tweeted":true,"attachment_file_name":"descrizione.png","attachment_content_type":"image/png","attachment_file_size":172842,"attachment_updated_at":"2016-08-01T15:59:25.490Z"}]