How to Make 3D Printer Filament – Professional & DIY

With the ever-rising price of 3D printer filaments, many users have sought out means to make 3D filaments on their own. This is why I have written this article to inform you about how you can make 3D printer filament.

Recycling failed prints and leftover filaments of the same type (PLA, ABS, PETG) can be used to make 3D printer filaments. Blend the materials into pellets and feed them into a filament extruder. PET bottles can also be recycled to get PETG filament by cutting them into strips and feeding them into the extruder.

While this is a pretty straightforward answer, keep reading to get more details on how to make a 3D printer filament.

How to Make 3D Printer Filament

Here’s how you can make 3D printer filament:

1. Use a filament extruder with plastic pellets
2. Recycle PET bottles by stripping them

1. Use a Filament Extruder with Plastic Pellets

One way to make 3D printer filaments is to recycle failed prints and leftover filaments using a filament extruder. Before you begin this process, there are things you need to put in place. These include:

• Plastic pellets
• Filament extruder
• Filament spool
• Digital calipers
• Dehydrator or an oven

Let’s go through the step-by-step process:

• Choose your material (PLA, ABS)
• Dry your pellets
• Set up the filament extruder
• Load the plastic pellets
• Extrude the filament
• Measure the filament
• Adjust extrusion speed and temperature
• Wind the filament onto a spool
• Cool and store the filament
• Test your filament

Choose Your Material (PLA, ABS)

The first step is to select the appropriate plastic pellets for your filament. You need to collect the materials and sort them. Ensure the materials are of the same type, i.e. if you are recycling PLA, then all the materials should be PLA.

Also, you can consider experimenting with different materials to create unique prints with varying properties.

Dry Your Pellets

The next step is to dry the pellets and the prints. This is very important, especially if the materials have been in a store somewhere and accumulated moisture. Materials like PLA and PETG are very hygroscopic (absorb moisture from the atmosphere).

Therefore, to ensure a smooth extrusion process and maintain filament quality, it’s essential to dry these materials before use.

You can play the materials in either a dehydrator or an oven at a low temperature (around 50°C) for a few hours. Keep an eye on the materials to avoid overheating or melting them.

It’s also possible to  get failed prints and other material, then shred them into small pieces to melt in your filament extruder to create filament, though the quality needs to be watched.

Set up the Filament Extruder

You can now set up the filament extruder after drying your pellets. Carefully read your extruder’s manual and assemble the machine following the given instructions. Ensure that all parts are securely connected and that the extruder is placed on a stable surface.

You can purchase the Filabot Filament Extruder from Amazon to make 3D printer filament.

One user who purchased the device stated that it is a very nice product. He said while he’s had a couple of issues, the customer service took care of it and got the machine back on track.

He also stated that the product works very well and maintains a tolerance of +/- 0.02mm, but not at full speed. Although it takes some experimentation to get the settings just right.

He recommended investing in a small clip-on fan and a food dehydrator to keep your plastic dry before you extrude. Familiarize yourself with the extruder’s controls, including temperature settings and extrusion speed adjustments.

Preheat the extruder to the recommended temperature for your chosen material, which can usually be found in the extruder’s manual or the material’s specifications.

You can also create a DIY filament extruder as many others have like the Lyman Filament Extruder V6 from Thingiverse. It would take quite a lot of technical experience and knowledge to do this.

There are 5 previous versions before that, but this one is said to be the  simplest one that is easier to make and inexpensive. There are 69 STL files created in this folder, but less than 20 that are used, so pick the pieces you are capable of printing.

It has a construction manual which should give you a good amount of information to create one, as well as the wiring diagrams and BOM. Check out the Thingiverse page to see more info about it.

Here’s the machine in action.

Load the Plastic Pellets

Once the extruder has reached the appropriate temperature, carefully fill the hopper with your chosen plastic pellets. Avoid overloading the hopper, as this may cause issues during extrusion, such as inconsistent filament diameter or clogging.

It’s better to refill the hopper as needed throughout the process.

Extrude the Filament

After loading the plastic pellets into the extruder, turn on the extruder and observe the plastic as it melts and flows through the nozzle.

The filament should come out smoothly and consistently, with a uniform diameter. It’s important to monitor the process closely, as temperature fluctuations or impurities in the pellets can cause irregularities in the filament.

Measure the Filament

The next step is to measure the diameter of the filament as it’s being extruded. This is very important as variations can affect print quality. You can use a digital caliper to check the diameter of the filament as it comes out of the extruder.

The ideal diameter should be within ±0.05mm of your target diameter (usually 1.75mm or 2.85mm). Check the diameter at multiple points along the filament to ensure consistency.

Adjust Extrusion Speed and Temperature

You can adjust your extrusion speed and temperature settings if your filament’s diameter is inconsistent. Increasing the temperature can help the plastic flow more smoothly while reducing the speed can help achieve a more consistent diameter.

Consult your extruder’s manual for guidance on making these adjustments and be prepared to fine-tune the settings until the desired consistency is achieved.

Wind the Filament onto a Spool

As the filament comes out of the extruder, guide it onto an empty spool to keep it organized and tangle-free. Use a spool holder or a rotating system to ensure even winding.

Maintain a consistent tension on the filament as it winds to prevent overlaps or gaps on the spool, which could cause issues during printing

Cool and Store the Filament

Once you are done winding the filament, allow the filament to cool and harden before storing it. Cooling can take a few hours, depending on the material and the ambient temperature.

Once the filament is fully cooled, store it in an airtight container with desiccant packets to protect it from moisture absorption. Proper storage is crucial for maintaining filament quality and ensuring consistent print results.

Test Your Filament

You can now test your filament once it completely hardens. Before committing to a large printing project, it’s a good idea to test your homemade filament with a small print.

This will allow you to evaluate its performance and make any necessary adjustments to your extrusion process or printer settings.

Take note of any issues with adhesion, warping, or layer bonding, and troubleshoot accordingly. You can now fine-tune the process to help you produce higher-quality filament for future projects.

Most of these filament extruders are very expensive. You won’t find any factory-made filament extruder rig without a 4-figure price tag on them. There are plenty of resources available for DIY filament extruders at low cost online.

Some of these sources include:

• Instructables
• Felfil
• Medium (Alex)

One user who made filaments from old prints stated that the prints from the filament looked as if they were made from the original filament.

Another used stated that the filament he got from recycling old prints from his Filastruder was good. Most of the time he got a variance of around 0.03-0.05mm in the diameter of the filament.

He said that he got close to zero variance with some pellets that extruded much slower than usual.

He stated that it is much easier to maintain tolerances when extruding at 12″-18″/min versus 5″-10″/min at the industrial level.

Also, he mentioned it is better to let gravity pull the filament after extruding than using mechanical pullers that introduce more variables that have to be managed correctly to maintain accuracy.

It is also important to keep the pellets dry and use a mesh filter, this would prevent bubbles and contamination.

He also said that making your own filament is worthwhile not only on price but on variety. For example, if he wants to use a particular color but doesn’t need a whole KG of it, he can just extrude as much as he needs using a tiny amount of colorant.

He stated that filament extrusion is still very new, but it takes a bit of practice to get everything set up just right. Overall, it is easier than 3D printing.

Another user stated that he knows people who have filament extruders and they made comments that it worked great. But in his own experience, the process can be slow depending on your method and equipment.

He said the time spent trying to make a complete spool plus the cost of the raw materials doesn’t work out when compared to just buying a spool. In many cases, it can be more cost efficient to buy the filament directly, unless you have a big operation.

Check out this video from CNC Kitchen on how to make 3D printer filament from leftover filament and scrap models.

2. Recycling PET Bottles

Another way to make 3D printer filaments is to recycle PET bottles using a filament extruder. The machine used here is a refurbished filament extruder.

To begin the process, the PET bottle is heated to remove any creases, deformities, or moisture in the bottle. After the bottle is heated, the bottom of the bottle is cut off and the rest of the bottle is used to create a long strip.

The long strip is fed into the extruder which heats it and extrudes PETG filament from the other end. When the plastic strip is fed into the extruder, ensure the extruder is set to the right temperature.

This process is pretty complicated because the filament extruder used is a DIY machine, which means there may be inconsistencies while the machine is in operation.

One user stated that the recycling process is not easy for anyone interested in doing it. He started this process mainly out of curiosity and to test its feasibility. He said it’s still a work in progress and he’s working on refining each step of it.

Also, he stated that it’s not as strong as PETG, and it’s more brittle, probably because it is missing the glycol that PETG has. He was pretty surprised by how well the surface finish turned out.

He majorly used this material for functional prints but he might explore using it for more aesthetic prints in the future.

It is not the easiest material to print with and slight temperature changes can cause the print to fail relatively quickly. He is still working on finding a food balance between the nozzle temperature, retraction settings, and fan cooling.

He recommended a hotend temperature of about 250°C, bed temperature at 60°C, layer height at 2mm, infill at 15%, and wall at 2.

You can check out this video from Igor Tylman on how to make 3D printer filaments by recycling PET bottles.

That should help you to discover how to make 3D printer filament and get you started on the right track to see if it’s worth it for you.