How to Make DIY Filament for Your 3D Printer

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

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

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

Woman 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 or scraps left over by crushing small shredded pieces of plastic and then extruding it out into filament you can use for another 3D printing project.

Filament extruders come in a variety of 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 your own 3D printing filament, filament extruders such as the Filibot, the Filastruder Kit, and the Felfil Evo will do the job.

You can also make your own low-cost filament extruder.

Using 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 you'll use will depend on the extruder you're using, but here's a look at the general method.

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

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

  2. Put bigger pieces into a bag, and with a rubber mallet, break them down into smaller pieces, the smaller the better.

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

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

  4. Consult your extruder's documentation to set the correct melting temperature. These temps only have 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 your 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 will exit 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 your filament. Your DIY filament is ready for your 3D printing project.