3D printers are great tools, but the cost of filament adds up fast. Filament extruders let you make your own by melting inexpensive plastic pellets. And you can experiment with different plastics and blends, to invent filaments with new colors and material properties.
We tested two machines; both are reliable and easy to use, with a push-button temperature controller and simple switches for the heater and motor. We tested only ABS extrusion, as PLA requires cooling and neither machine is equipped for it.
Ideally, filament extruders could also recycle your failed prints. These two can’t, but the OmNom Project and Filabot’s Reclaimer grinder (still in the works at press time) are aimed at this recycling problem, and we’re watching with great interest.
Price as tested $749 assembled
Open source? Yes
This is the Ferrari of filament extruders — it’s fast, loud, and looks well-built. It can extrude 1kg of material in 5 hours. Even the fastest printers can’t use up filament at that rate.
Unfortunately, like a Ferrari, it’s also a bit expensive: $649 for the kit, $749 assembled. (It’s an open hardware project, so you can also build it from scratch; see how on page 50.) Filabot also sells ABS pellets, priced from $5/lb (0.45kg) to $41/10lbs (4.5kg) for bulk quantities. Ultimately this machine is a good choice for people who want to make filament in bulk and maybe sell it, and don’t mind a little bit of noise.
Price as tested $260 kit
Open source? Yes
The Prius of extruders, the Filastruder is on the slower side, makes very little noise, and is well-priced — a bargain at $250 (or $260 with a 3D-printed hopper). Filastruder sells polyamide (nylon) powder, but recommends buying pellets from Open Source Printing: ABS for $8/2lb, PLA for $7/2lb.
The Filastruder takes 12 hours to extrude 1kg of filament, about 40% of the speed of the Filabot. It’s as quiet as a 3D printer, emitting only a hum from its DC extruder motor. If you just want to make filament for yourself and a few friends, the Filastruder is an economical machine.
- Extrude from a tall table, at least 1m (39”) high. On shorter tables, the filament may not have enough weight to pull itself downward and may build up a pile at the nozzle.
- Both machines can extrude 1.75mm or 3mm filament. Just heat up the nozzle, unscrew, and swap in the desired size.
- Filament winders are being developed (Filabot sells a beta kit) but manual winding isn’t difficult. Don’t wind it like a yo-yo since this introduces a twist that will cause tangles. Instead, spin the spool, using one hand to tension the filament as it wraps around.
- To make colored filament, mix special color pellets (known as “masterbatches”) into natural ABS pellets at a ratio of 1:50, or 1:32 for richer colors.
- It’s fun to create fades between colors. The effect gives printed objects an organic look.