Tapered thread extruder auger

I just spotted this, used for 3D printers, might make a good upgrade to the auger  in the extruder as it has a tapered screw which increases the pressure of the melting plastic as it moves towards the nozzle. This is how the bigger machines work.


I have a design for my second version of my filament maker dubed the FilaFactory. The test bench of the machine can be found here.

Yes the screw does increase the pressure. The general guideline is 3 to 1 compression. so at the end of the scree the volume per flute of screw would decrease by 3 times. This also adds alot of temperature. As the volume decreases the pellets have less area to move around and rub even more between themselves and the sidewall of the extruder. Expesially as the screw is being turned as the pellets are literally being grinding into the walls of the extruder. It is found that the compression style screw can contribute almost 75% of the temperature needed to softened/melt the plastic.

You can see a little bit about my screw that is 10 inches long and 1″ in diameter and has 3:1 compression. It is designed to be manufactured on 4th axis.