Low cost DIY filament extruder by Xabbax

Low cost filament extruder made from 10 mm ID stainless steel tube, silver soldered inside an ordinary plumber 15 mm copper tube (melt zone) Auger is a 10 mm wood drill bit with the end cut off 5-10 mm in the melt zone. 1 mm hole in a brass endstop at the end of the copper pipe. Aluminium block with a 15 mm hole to fit around the copper pipe. Fixed to the outside of the aluminium two 220 volt 200 degree PTC heaters( I tried 12 volt 230 degrees but the temperature was to high) Insulated with glass fibre cloth. The ptc heaters are available on aliexpress for $1 each)
System driven with a car windscreen motor at the low speed (I have a 2 speed motor - salvaged from scrap yard)
I use the white plastic that is in the inside of the doors of scrap refrigerators. Cut it up with a circular saw and extrude that to a filament of 1.75 mm
I use this filament in my Delta printer on a daily basis.
The trick to have a nice filament is to let the filament run over a copper pipe that is suspended in front of the extruder and let natures G force take over. I fix a weight(clothes-peg) at the end of the filament as it comes out of the hole untill it reaches the floor and then move the end of the filament to the outside of a circle approximately 1 meter away.From then on the G force will take over and produce a nice circular movement of the filament to roll it on the floor .
The slightest air movement or other external force that you apply to the extruded filament will result in a kink in the filament - no fans required.
No fancy electronics involved.
Material cost to should be less than $100
This extruder was only tested with the white refrigerator plastic ( I think it is ABS because it will desolve in acetone ) - no ABS pellets or any other plastic tested.