Filament extruder design help

I cant speak english very well, but “i understand it very good”
Im new in 3d print
I want to make a filament extruder with this abilitys:

1. Produce “0.5 to 1 kg/h” with good quality
2. Work with ABS, PLA, and removed 3d printed parts (Like some desktop extroders)

I watched many video in youtube, and read many guide and step by step diy extruders, but i have some questions to start my project, and i need your helps!

My first problem is gearmotor, i need to understand appropriate “RPM” and “torque ” for my purposes. I read a lot about it and i am confused… I need your help to introduce me the right motor for my extruder

My other question is about the right length and diameter of barrel and auger, and number of heater and power (watt?) of them.

In electronic parts and assemble of them i have not problem 🙂

My english is not good, please fill this chart and thank you very mach

1.motor details 2.barrel and auger sizes 3.everything you now that you think it can help me.

Thank you!


Is this wiper motor good for my extruder???
Low: 40 ~ 55 RPM
High: 55 ~ 82 RPM
Torque: 20 ~ 30 n.m


Hello again!

I’m not idealist or utopist. I’m realist; but I think, I can make a better extruder than werbewunder’s extruder.

This is a challenge for me, and maybe I’ll succeed or fail. I will try and the result is not important!

I will share my project step’s here; for the experts, who remind me if I made a mistake; and for beginners, who need help and search about “make a extruder” in Google, and come to this forum as I came.

# I found that 150~180 nm torque could be enough. That mean a 1kw motor is good which supplies 160 nm in 60 rpm, and more torque in lower rpm.

# if motor is 1500 rpm, I can use a 1:20 gearbox (or 1:10 gearbox and a 1:2 ratio chain drive) for max 75 rpm, and I can control rpm with a motor drive to get lower rpm.

# for screw, wood drill is usable but not great. I have to find a special screw, or order to build it to a workshop if it possible (and if not, in the end, I have to use a suitable drill).

If it was possible for me to buy an extruder, i did not have this troubles; but experience has proven that some limitations, promote people.

regards (V)

@irinah I had not seen 3Devo’s extruder before but it looks good.
It’s pretty much the same as any other home filament extruder out there, but seems like they did a pretty good job enclosing the unit to ensure ambient heat is controlled and their control interface is very complete.
The only thing I dislike is:

*They only show 3mm extrusion, never show their machine extruding 1.75mm filament
*There are no reviews on the internet, all videos and unboxings are from their own channel and the only other one I found is from one of their resellers
*Extrusion is super slow due to using a small DC motor, they claim to produce 100grams of filament per hour, which means 10hrs to make a spool of 1kg.

Werbewunder will release his Mini Filament Maker diagrams and stl files soon so I would advice to wait for it 🙂

yeah, that’s the big question, what sort of plastic can be used for detailed printing, and for less detail (3mm) printing.
possibly you can only recycle old PLA/ABS with the PP machines but that’s it. DH never really lost a single word about but suggested in the video that he’s printing recycled plastic. better you ask him your self because i am tired of it and won’t get honest an answer anyways…

Thanks for the replies and the link to Werbewunder’s latest update! He really does cool stuff! Indeed time to get things dirty. 🙂

While browsing around for what other extruders are there on the market, I also came across this: Filament Making (Part 1): Meet the 3devo Filament Maker | 3devo - YouTube . It seems like a more simplified version compared to the DIY version that Werbewunder is building. Any of you has experience working with 3Devo’s product or more importantly with filament produced by them? It seems a well-rounded product, yet the mechanism described is maybe too simple for it to really give usable filament?

werbewunder made a good update last week, check it out :

i have no feedback that the filament works well, nor this will work with shredded plastic at all but time to get hands dirty 🙂

*Precious Plastic Extruder: That’s it, an extruder…

*Werbewunder’s extruder: Extruder with a special extrusion screw, VFD controlled motor, water bath, filament diameter controlled through digital micrometers and micro controllers, different nozzles for each type of filament , automatic winding mechanism, filament puller, filament stretching pulley system…

Anyone using filament for 3D printing from recycled plastic on a regular basis? Is it reliable? What kind of materials are you using? PET by itself or mixed with something else? ABS? PLA? And what kind of technology do you use to make it? Is the kit available on PP reliable enough?

I’ve noticed that people here are mentioning werbewunder as a good version, but didn’t get the chance to have a closer look on how different that is from the PP version. Anyone with experience here who can point that out to me fast?

Thanks! 🙂

looking at the options, someone should set a bounty on this topic, i am sure the right freaks can come up with something.

you also have to consider that ‘werbewunder’ is using ready to use granulat, there are are worlds between the plastic from the PP shredder and those high quality chips from the market (1-3 mm).

from my experience (testing various plastics against various screws), you need actually quite some torque, min. 750W, at 1:20 and a proper screw to extrude nice and consistent plastic. the average chip size from PP machines are up to 4-5 mm, depends on how often you re-shred it, but even though, there isn’t a guarantee that it will be fine enough, and that very chips size is basically dictating your extrusion, down to pretty expensive details! Whilst at it: I may also remind to quite some comments here in the forum (and also external experts we consulted on this topic): don’t use a wood drill to make good or usable filament, period. Don’t even think about!

i would suggest also to search for low-cost machines, ie: search for “filament DIY NEAR recycled plastic”. There are couple of machines with some details to take away regarding building your own.

Those Industrial filament extrusion systems I saw here and there had something in common: motor/extrusion-screw/reducer and all is rather a man high machine, with hell of water baths, coolings, and pull systems. I rather doubt you can do with less without being trouble when it comes to up-time, quality, etc… But may be the DIY niche could indeed provide some low-end filament, good enough to print large things only.

keep digging folks, seems like we really have to build such thing from scratch, there is little to no information about, nor open-source.

A lot of thank you for that “pdf” file, i must study it.
In my country, these extruder’s kit (and even the filament) are scarce and expensive, and I have to make one of them myself.
Your tips are a great help for me
thank you

Thank you for answers

Do you mean that I can use any powerful motor when I can control the rpm and torque? It is very good

I watched most of Werbewunder’s (and some others) channel videos and i really liked his pro extroder’s from others, but I did not understand what motors he used in his 5 kg and 1 kg extruders, and he does not have any technical brochures for it.

Last week, i tried a lot to diagnose his 1kg extruder’s motor model and information (RPM and Torque) I took a few screenshot but failed. I just found it is a DC 24V  “etonm” flat gearmotor and no more!

This guy from La Coruña is supposedly making 3D printer filament with a Precious Plastic extruder, I assume he’s using a 3mm extruder, you might reach out to him for more info

Assuming you fill a spool with filament, next thing I would do is to try to pass/squeeze that filament through a 1.85mm hole (assuming you are printing with a 1.75mm extruder). If the filament can pass through that hole without getting stuck at any point then it can be considered usable, if it gets stuck then you either need to grind the filament to reduce the thickness or just cut it at that point. Trying to use filament thicker than 1.80~1.85mm will result in your printer’s extruder getting clogged.

Another option is to connect a caliper to an arduino and read the filament diameter right after being extruded, and store the serial output in a file/spreadsheet. After finish extruding you can sort your data and find what’s the minimum and maximum thickness to determine if your filament is usable.

Too thick = Extruder will get clogged
Too thin = Extruder gears won’t be able to push the filament through the nozzle


please study this carefully :

after doing a dozen screws and barrels myself, I’d say the barrel should be polished and hard much as possible, steel is pretty much the last thing I’d take. So, if you manage to get anything hard, with a nice surface finish, you will be on the safe side. stainless however is rather soft, when cutting or turning it, it’s much like aluminium, like ‘gum’, easy to damage but there are quit some variations out there….

@xxxolivierxxx, great, good to know. i am trying to get in touch with werbewunder, in hope to get a little phone call. having a filament DIY kit is on our top list and it seems people could do it with much less than i’d have ever anticipated.  He said however that he’s going to release a major updated in a week or so.

anyhow, let’s say some basic filament can be done, what are the next level steps ? we have some workshops planned for the end of the year and at that time i’d need something usable, any help is welcome

@anne-barbier no offense intended, but the filastruder, filabot, felfil Evo and Noztek are garbage. They are good at what they do: Extruding plastic, but there are zero elements to control filament tolerances, which render the filament useless for 3D printing. From all Filastruders that have been sold, I only read comments from 3 people who managed to get some decent PLA filament out of it. ABS is extruded better but still not the same quality as rolls purchased from known brands.

At this moment, the closest thing to a DIY extruder that works is Werbewunder’s extruder. Hugh Lyman made a nice extruder as well, but doesn’t work very well with PLA or any other temperamental plastics.

found something ready here : Filastruder Kit, 300 bucks just

that’s an awesome extrusion machine, small and compact, anyone found more details about this machine (i tried to find it in the youtube descriptions)? i am wondering whether his screw is available somewhere.
anyway, this sort of machine should be definitely  the PP machine catalog 🙂