Hello,
I’m a mechanical engineer student.I have a graduation project .The graduation project is ABS filament injection.I will use an extruder mile in my project.Extruder mile diameter is 16 mm and injection material is ABS.I made all the calculations for extruder mile.But I have a few problems.
Problems:
1-How to calculate outer diameter for barrel?(or barrel thickness)
2-How to make the motor value for the extruder mile(shaft)?
3-How many heater should I use?
4-How should the location of the heaters?
hi, i can’t answer all but point to some sites,
this here is a conventional filament mile, for whopping 40K $$, just to get an idea.
here is a low-cost variant of PP but it still lacks evidence and data that the filament is any good, work in progress nonetheless 
from what i know, making good filament doesn’t require too much machinery (still beyond 2 – 4 + K $$), the crucial part is the tuning, it seems you can spend months to dial in all for your setup. all depends on motor, screw, fans, nozzle parameters/specs. there is no ready-to-go receipt really possible though. here some insights on the subject. turns out that even you found the right settings, you can start all over again for different plastic types which also want different screws …
i hope this helps a little, for now i can only tell you :
– make sure you have a good screw, barrel, 350 – 600 $
– make sure you good heat bands (50$ – 100$ per piece)
– make sure you have good fans (PID controlled, near 200$ the unit, you may need 3-4 )
– have well controlled water baths, 2 – 3 meter long, that’s the cheapest segment
still, there is no real sign this could possibly work with recycled plastic. you can however print plastic dust or pellets right away, PET is a good candidate, with a little fiddle you can place this here right before the extruder, all you need is to grind the plastic near dust …eventually you can convert old mill machines (food, weed,…)
good luck