How to Make DIY Filament for Your 3D Printer

For the die-hard DIY crowd, making your own filament keeps costs down

3D printers use various plastic printing materials, also called filaments, with an array of technical names and acronyms, such as ABS and PLA. Filaments are plastics, also known as polymers. Filaments are a common 3D printing material because these materials melt when heated rather than burn, and can be shaped and molded.

There are many types of 3D printer filaments to buy, ranging in price from $15 to $40. But serious do-it-yourselfers might be interested in making filament using discarded or failed 3D print projects.

Person using 3D printer with 3D filaments in various colors
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Filament Extruders

Filament extruders are machines you can buy or make that turn shredded plastic into filament to use in 3D printers. Filament extruders recycle failed 3D printing projects and leftover scraps by crushing small shredded pieces of plastic and then extruding it into filament for use in another 3D printing project.

Filament extruders come in many sizes with different features, but the basic functionality is the same. Push plastic pieces through a heated area. The plastic melts into liquid plastic, which is extruded through the machine's nozzle as a strand of filament.

If you're interested in making 3D printing filament, filament extruders such as the Filibot, the Filastruder Kit, and the Felfil Evo will do the job.

You can also make low-cost filament extruder.

Use a Filament Extruder to Make Your Own Filament

Along with a filament extruder, you'll need heavy-duty scissors and a rubber mallet. The exact process depends on the extruder you use. Here's a look at the general method.

  1. Gather and collect your failed prints and sort these by color.

    Only recycle parts that are clean and free of solvents and adhesives.

  2. Put large pieces into a bag and, with a rubber mallet, break the pieces into smaller pieces. The smaller the pieces, the better.

    PLA material tends to turn into a powdery state. ABS material grinds down into a mulch-like state.

  3. Depending on the extruder, attach the nozzle firmly and securely. Follow the particular extruder's instructions.

  4. Consult the extruder's documentation to set the correct melting temperature. The temperature only has to be hot enough to melt the plastic.

    Setting the right temperature with the kind of plastic material you're using is a trial-and-error process.

  5. When the extruder is heated up, fill the hopper about halfway with plastic scraps.

    Make sure not to overfill the hopper.

  6. Add more material as the extruder turns the plastic into filament.

  7. The filament exits from the nozzle. Gently guide it into a coil as it comes out so you can spool it. Avoid touching the filament.

  8. When you've made enough filament for your project, turn off the extruder and spool the filament. Your DIY filament is ready for your 3D printing project.