As of now I am in the process of building a filament extruding line and intend to produce it in series.
The first version that was using a Lewis drill bit intended for testing purposes worked just fine and got sold.

Now I work on a new model with specially designed plastic extrusion screw and longer barrel.

Here are the specifications:

-Barrell L/D (Length to Diameter) ratio: 26 : 1;
-Compression ratio: 2.5 : 1;
-Barrel diameter: 26 mm;
-Heating zones: 4 (with temperature controllers);
-Stainless band heaters for 38 mm barrel: 5 pieces;
-Triple phase 380V Varvel coaxial gearbox electric motor 180 watt 1400 RPM, 20 mm shaft (made in Italy);
-Gearbox reduction ratio 46:1;
-Max RPM at 50 Hz: 30 (more at higher Hz);
-Torque @ 30 RPM: 52 Nm;
-Mitsubishi Electric Frequency Converter;
-Specially designed die with long land length, small internal angle (30 degrees) and easy to replace internal melt filter screens with various sizes;
-Diameter of die: 2.5 mm;
-High pressure high temperature gasket between nozzle and barrel to avoid pressure loss;
-Water and air dual cooling for produced filament;
-Water tank;
-High speed puller with silicone rubber wheels and Nema 17 motor controlled by Arduino with LCD and encoder;
-Winder based on Filawinder but with much bigger 12 kilograms spool;
-Extruding speed: 1-1.5 kgs/hr depending on polymer choice;
-Precision of extruded filament: +-0.05 mm, but I expect it to be better with the new extruder screw;
-Expected power consumption for 24 hrs: 17 Kw/hr (2.5 USD/day at 0.15 cents/KW/hr);
-Emergency Stop button, on and off button, speed of extruder motor can be adjusted in 0.01 Hz increments also speed of puller allows for fine adjustment;
-Electrical panel is done by a professional;
-Differential protection to protect the operator from electric shock, it needs a grounded 220 volts power outlet;
-Stainless steel hopper with capacity is 3.5 kilograms but it should be refilled often.

I can also provide ABS masterbatches.
My location is in Europe, Romania and I can arrange shipping by truck and also provide invoice for the paid money.