The Plastic Extrusion Tool takes in a feedstock of 3mm ABS plastic filament. The filament is compressed between a servo motor driven knurled pulley and an idler wheel. The filament is then forced down through a 0.50mm nozzle heated to 230°C [446°F].
Initial Plastic Extrusion Toolhead
The black parts that comprise the body of the extruder were made on a commercial 3D printer. In the above image, the extruder controller board [left] provides power to the nichrome wire heated extruder barrel and nozzle using PID control. The brass nozzle and heater barrel are covered with ceramic insulation for better temperature control. This heated portion is then itself insulated from the plastic tool housing via a PTFE tube, which was later changed to PEEK.
Backside of the Plastic Extrusion Tool
Six 1/4″-20 screws fasten into the tool head to secure it to the Z stage.
First Moutning the Plastic Extrusion Toolhead Mounted onto the Z Stage
Current Plastic Extrusion Toolhead
This is how the current Toolhead looks. The PTFE tube was replaced with a PEEK version, which is better suited to handle the loads of the melting plastic under temperature. Also, an aluminum plate was bolted to the black housing to provide more structural rigidity. A magnetic rotary encoder [right] provides closed loop feedback on the drive motor for more accurate extrusion, though getting this to work correctly with the extruder board firmware has proven difficult. Also the magnetic rotary encoder board is mounted to the drive motor via a custom part that was printed on this machine.
Where did You print that extruder body? On what kind of machine? I am courious on quality of the part. It’s obviously FDM, but it shows no typical little defects usually found on Repraps.
Yes it is FDM, and was printed on a commercial machine.