The device costs less than $700 in materials and can be fabricated in about 24 h. It can make filament from pellets, regrind, and composite wastes. A full description of the build can be found here: Aubrey L. Woern, Joseph R. McCaslin, Adam M. Pringle, and Joshua M. Pearce. RepRapable Recyclebot: Open Source 3-D Printable Extruder for Converting Plastic to 3-D Printing Filament. HardwareX 4C (2018) e00026 doi: https://doi.org/10.1016/j.ohx.2018.e00026

In addition all other needed files (design files, STLs, code, etc.) are here: https://osf.io/9hsmb/

FreeCAD users: The entire assembly is available in the STP file in the zip located in the OSF link above. Open it in FreeCAD and pick what part you would like to modify, export it as .stp, and you will be left with just the part you need. Once you have that, you can save it as just about anything.