Recycle your failed 3D prints! Make new filament at home.

Recycle your failed 3D prints! Make new filament at home.


3D printing can produce quite a bit of waste
over the years that usually lands in the trash. Wouldn’t it be great if you could recycle
your failed prints, support structures and purge blocks into new filament? Today I’ll show you how I managed to extrude
new filament out of scraps at home. Guten Tag everybody, I’m Stefan and welcome
to CNC Kitchen. Recycling failed prints is something like
the holy grail of 3D printing. There have been DIY filament extruders around
for a couple of years that enable you make your own material out of resin pellets that
you can purchase. They are basically built up pretty simple. A high torque, low rpm motor drives an auger,
so big wood drill that sits inside of a pipe. The pellets are then added via a slot into
that pipe and get transported to the front where, very similar to a 3D printer, a heating
element and a nozzle sits. The melted plastic then flows out of the nozzle
and “tada”, there is your filament. On these simple extruders the diameter of
the filament is only partly defined by the nozzle and is also dependent on temperature,
flow rate, weight of the filament that stretches the just extruded portion and a couple more. This was maybe a bit exaggerated since most
systems can be quite sensitive to small changes but making your own filament at home is totally
doable, even though maybe not reasonable in monetary terms, if are okay with some tinkering. Though there is not a lot of information about
people who recycled 3D printing scraps and made new filament out of it. I bought myself a Filastruder Kit a couple
of months ago and finally got around putting it together. Honestly the built itself wasn’t the most
straight forward thing and also the first couple of runs weren’t always a success
and I had to use the file on some of pieces and straighten the pipe so that everything
ran smoothly. I also purchased the so called “Filawinder”
which is a separate unit that directly winds the filament rolls and is essential if you
want to extrude PLA with a consistent diameter. Both Filastruder and Filawinder kits will
set you back around $500 but the design is quite simple and there are also a couple of
open source designs around that you can mostly build from hardware store parts. At first I ran almost a pound of the included
ABS to clean out the extrusion part before I went to my desired material: PLA. After setting up everything properly and tuning
everything in getting filament with a kind of constant diameter didn’t seem to be a
huge problem. The thing that was bothering me though was
that if you don’t want to buy PLA pallets in bulk quantities, a kilo of PLA pallets
cost me almost 10€ which comes quite close to a cheep roll of generic filament. So if you want to save money on filament with
such a system you’ll have to print quite a bit! Now we get to the interesting part and this
is recycling old PLA prints. I have been gathering all of my PLA scraps
for the last year and paid a lot of attention that I don’t mix any other material in there
which would then spoil my material properties. The thing is that I can’t just put these
parts into the extruder to get filament because the material that is fed can’t be larger
than 5 mm on any side. In order to shred the material, I tried to
applied two techniques. The first one was to use a modified paper
shredder that can cope with lots of parts if they are not too thick. I made myself a plunger that I don’t accidentally
get my fingers into the dangerous shredding bits. Bigger parts need to be broken down at first. At the moment I’m doing that by hand but
maybe a wood chipper would help me there. Michael over at Teaching Tech has also done
some investigation on that topic so check him out! The particles that come out of the shredder
often don’t meet the 5mm requirement so I additionally run everything through this
cheep mixer. If you have a proper one to spare than you
could maybe do most of the shredding directly in it. Only make sure that you don’t run if for
too long and melt the plastic inside. You should also really wear a couple of safety
googles since shredding can produce quite dangerous plastic shrapnel. The material is now run through a sieve that
I 3D printed by using no top and bottom layers and only adjusting the infill density to a
point that the mesh size was around 5 mm. Everything that’s too big goes back into
the mixer. The remaining particles are now basically
usable, the only thing that just needs to be done is to properly dry them because otherwise
we’ll get extrusion issues. I simply put the shreddings into a laundry
bag and put everything in my food dehydrator, that I also use to dry my filaments, at 65°C
for a night. Normal PLA pellets are usually extruded at
around 160°C in the Filastruder which gives you a slightly undersized filament with the
standard nozzle and works perfectly in basically any 3D printer if you increase the flow multiplier
a little. Running my first tests I noticed that if I
run the recycled filament at these low temperatures some particles don’t perfectly melt and
give the material a grainy texture. After bumping the temperature up all the way
to 175°C the material extrudes very smoothly but due to the lower viscosity of the melt
ends up way undersized so I drilled the nozzle to 2.1mm. Anyways, so the shredded and dried PLA scraps
are now added to the hopper. After a bit the filament starts to extrude
it is slowly guided through the position sensor to the winder. Even though the line laser might look like
a laser measuring device, it’s actually only used to sense how far the extruded filament
has sagged and then winds it up a bit so that the tension on the filament caused by its
own weight stays more or less constant. Extruding the recycled plastic actually worked
well the only real problem I had was that the sharp cornered shreddings tended to jam
in the hopper so I had to constantly gently hit the it to get a uniform material output. I tried adding a fan with half of the fins
removed but that didn’t really help either. In a second run I added 50% virgin PLA pallets
to my recycled material which then fed really well and created a quite consistent and beautiful
filament. The 100% recycled material that I kind of
fed manually ended up with an average diameter of around 1.60mm and varied in the range of
+-50um. The extrusion rate is around 100g an hour,
so a full roll will take quite a while. The color of course is a mixture of all of
the parts you recycled. I call my first batch “Trash Bag Khaki”! The material has a nice, smooth surface and
feels like regular PLA and isn’t overly brittle. Even though I mixed my shredded plastic well
the color is not perfectly constant over the roll and I think it’s kind of impossible
with such a setup. That doesn’t really bother me though and
I’m thinking about getting some black pigments in order to overtone the rest of the colors
and get a nice, black filament in the end. All of the parts I printed so far came out
very nicely. I didn’t have any jams so far maybe also
because I use a melt filter, which is a fine mesh in front of the nozzle that keeps bigger
particles from getting into the filament. And this might be one problem of recycled
filament. Not only do you really need to pay attention
that you only shred the same type of plastic, you also need to be aware that any dirt on
your recycled parts will end up in your filament. So I might be trying to wash my particles
before drying to get even better results in the end. This was my prove of concept on recycling
scrap 3D prints into new, very usable filament. I didn’t go into huge details on the setup
and everything since I really want to hear what you guys wanna see! The things I think I still need to tackle
is how I can properly shred all of my old scraps and how I can feed them consistently
in the hopper. I still think I was very successful and even
though this might not be something for everyone, I really want to do more in this direction
so I’d really like to hear your ideas on this topic. Where could I improve? What other investigations should I do? Do you think recycling scraps is worth the
effort? Please let me know down in the comments! Thanks for watching everybody! If you enjoyed the video and maybe even learnt
a bit then hit the like button, subscribe to the channel and consider supporting me
on Patreon. Don’t forget select the bell in order to
get notified when new videos are being released. Auf wiedersehen and I hope you join me in
the next video.

Danny Hutson

100 thoughts on “Recycle your failed 3D prints! Make new filament at home.

  1. Did you know that I record a bi-weekly PodCast with Thomas Sanladerer?
    LISTEN TO IT: https://www.youtube.com/channel/UCzUgJrG-w_KQexroYkJR9XQ

  2. To shred better
    1. Melt down the scrap
    2. Pour into a mold or press into a mold if it is play dough consistency.
    3. The mold should be a shape that is easy to chop
    4. you come up with the best shape.

    Or you could easily chop the new extrusion.
    Another idea is to have a filament recycling business. Buy scraps from people in your city and sell the recycled product. Economy of scale could make it viable. People could ship scrap to you if they have enough.
    Look at a pasta extruder. The ones that make small sized pasta . There is a spinning knife that cuts the extrusion as it comes out

  3. ngl, I literally thought the thumbnail said “making filament from failed parents” and I was really questioning the YouTube algorithm

  4. I feel like the 3D printer nozzle is just pushing all over the top of the print as its printing i can see it wafting small bits of plastic around

  5. Extruding your own filament is the 3D printing equivalent of loading your own ammo. The gun people out there will know what I’m talking about.

  6. This is really awesome! I'm all for recycling plastics, but this is pretty expensive to do. Hopefully more brands try to enter the scene to drive the price of these machines down… My 3D printer was expensive enough as is

  7. I'm curious about if there would be a noticeable change in color if you used only one color.
    Like would it fade would it darken

  8. man, this feel like the waste of beautiful colors to jam the mix, considering that you could recycle your mistake few times over in many neon set

  9. This could be useful to recycle material in some universities where students can use 3d printers

  10. Upon close up, you can see long but thin pieces. I'd run them through the blender a little bit more and do a manual check of some samples to look for long but thin pieces

    Also adding the pigment could be a great idea, but you would run into issues of consistency

  11. I recommend a blend tech blender for shredding. I'd also add cold watter in during the blending process to A. Wash it and B. Keep it from melting while grinding it up.

  12. If you recycle already recycled material, then you'll get more constant color next time.
    As for other things, I'm pretty sure that raspberry pi or something like that would do the same job as more expensive equipment.

  13. it's kind of idea by this link

    recycle material it very helpful in the maker world

    hope you can keep studying this part
    https://www.youtube.com/watch?v=oRNgIu3K7vg&list=FLgUuvdPyjipPMt6iHM8WZKw&index=6&t=0s

  14. This is awesome however its too expensive. It looks like a very basic machine and I bet it would be cheaper to make yourself.

  15. if you really want a consistent color you can either separate them by color or just after having extruded it trough the extruder chop them off and extrude it trough it again!

  16. It doesn’t seem worth it with the amount of time it takes to make it it would be much better if there was a business you could just send your scraps into and they would send you back a roll

  17. Have you considered to melt down the scrap parts instead of chopping them? Doing so, you could de-moist, filter out non-melting strange elements and pre-process your material to be easily fed into the extrusion system. It could also helps with the colour, depending on the melting procedure.

  18. Thank you for this info! I'll probably do this since I'll be generating a fair amount of PLA waste when commercially making 3D printed parts. Side note: Your English is fine but maybe try not to say Khaki very much lol (please take this as a friendly joke)!

  19. Loved this video! Have been wanting to start making my own filament for ages so has been really interesting to watch you do it. There are some great open source designs out there, but I think the main issue is the slow rate at which these personal level machines produce filament, ends up making the process so costly by the time you factor in your supervision time! Waste is such a massive issue for 3D printing and only going to get worse, would be great to see filament manufacturers offer to recycle peoples scrap, but having spoken to contacts in this industry it seems the issues you mentioned with dirt and other plastic contaminants are the stumbling blocks for them too.
    Keep up the good work anyway, hoping I'll be able to pitch in soon as well.

  20. Wow.. 10 Euros and more for 1KG Filament pieces…. for making own Filament-Stripe….. then i more like to buy 1KG Filament Stripe für 9,90€… so i more save money.

  21. I got a 3d pen that works great but I get more recyclable material because it's not a computer making the movements … but 3d pens are very fun and easy to use and instead of 200 to 400 bucks for a 3d printer this only cost me 30 bucks and then 20 for filament.

  22. A large blender to break pieces down, and a food processor to get a good consistency. That paper shredder doesn't have enough speed to break things up properly.

  23. As you find out here, the huge problem with plastics of any kind, is that it's way cheaper to produce them than to recycle after, that's true on an economic perspective due to the fact that it's also true on an energetic POV. You really need industrial volumes to make this process worth the effort, that's sad.

  24. This is pretty cool, but definitely a long term thing. I'd happily save up plastic bits for a few years before doing this.
    Really like it though, since over enough time it's a great money saver and much better from an environmental standpoint.
    Also hopefully in a few years it will be easier to do this than it is right now./

  25. You should break your parts into a powder because that will leave no room for error and will be easier on the filament maker. Make sure everything is mixed up and adding pigment will probably help with any color problems. There are many ways to break large pieces into small parts and then into powder, but I have not tried anything (since I can not afford a filament maker.) You can always just smash the parts until they become powder-like. E.I. break the original failed prints into small pieces, then with your desired method of compacting, compact the pieces into smaller pieces and repeat till you get it to be powder-like. Be careful not to breathe the particles!

  26. So you are telling me that construction does the job better than the 600€ machine I just saw in another video?

  27. I know recycling filament isn't as easy as it seems at first. But I think it's a very important problem to tackle. Many people (especially the ones who aren't so involved in 3D printer) see 3D printers as a rather environmentally friendly thing, since they let you produce things right at home and it seems quite easy to make new filament out of old prints and print it again, sort of bypassing the industrial recycling etc.
    But the way it currently is, I think 3D printers are quite a concern when it comes to wasting plastic, especially as they become more and more popular. Very few of the things I print are perfect on the first try, not because the printer fails, but because the design isn't exactly the way I want it, some dimensions aren't quite right etc. So it often takes multiple prints until I get a useable version. And since 3D printed parts don't have any markings to show which type of plastic they are made of etc., the failed prints are basically impossible to recycle and so none of them are recycled. Basically 3D printing is currently the exact opposite of environmentally friendly, at least when it comes to recycling.
    Anyway, I think it's good if 3D printing channels upload videos showing how one can recycle failed prints since it motivates people to try it themselves. And since there are tons of tutorial on how to get good prints but very little tutorials on how to recycle your failed prints successfully, personally I also think videos on recycling filament are a lot more interesting.

  28. No printer guy here, lol. I actually have wondered about this to my friends with printers and thought of this as the holy grail as well! Is there a way to melt the pla into sheets for easier reduction in size? If not I wonder about grating/shaving? I will say, being a tree trimmer, you wouldn't want to use a wood chipper, lol.

  29. Why can't a 3D printer use a hopper that feeds scrap into a melt zone that provides a constant supply of plastic to the nozzle head?

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