3D printing has evolved to a point where dual extrusion isn’t really that special anymore. A few years ago, a two-color frog print would have been impressive, but this isn’t the case anymore. The Midwest RepRap Festival is all about the bleeding edge of what 3D printers are capable of, and this year is no exception. This year, we were graced with a few true multicolor filament-based 3D printers. The biggest and best comes from [Daren Schwenke] and the rest of the Arcus3D crew. This printer is a full color, CMYKW mixing printer that’s able to print in any color imaginable.
The bizarre mixing hotend, powered by a brushless motor
The electronics for this printer are, to say the least, very weird. The controller board is BeagleBone Black plus a CRAMPS running Machinekit. The hotend is bizarre, feeding six PTFE tubes into a weird water-cooled assembly that mixes and squirts filament out of the nozzle with the help of a small brushless motor. Thanks to a clever design, the end effector of the hotend weighs only about 150 grams – about the same as any other delta printer out there – and this printer is able to move very fast.
Over the last year, we’ve seen a lot of improvements in the state of multi-material and multi-color extrusion for 3D printers. At last year’s Maker Faire NY, Prusa’s i3 quad extruder made an appearance alongside the ORD Solutions RoVa4D printer. These are two completely different approaches to multicolor 3D printing, with the RoVa mixing filament, and the Prusa merely extruding multiple colors. Both approaches have their merits, but mixing extruders are invariably harder to build and the software stack to produce good prints isn’t well-defined.
Even though we’re still in the early years of full-color filament-based printing, this is still an awesome result. In a few years, we’ll be able to look back on [Daren]’s efforts and see where our full-color 3D printers came from – open source efforts to create the best hardware possible.
[Daren] has been working on this printer for a while, and he’s been uploading all his project updates to hackaday.io. You can check out the build log here.
At the Midwest RepRap Festival, maker Daren Schwenke showed off his homemade Arcus 3D “true color” 3D printer.
In the makersphere, we’re seeing sophisticated hack jobs that seem capable of outdoing existing systems at their own game. One recent example is Daren Schwenke’s Arcus 3D printer.
Schwenke just demoed his creation at the Midwest RepRap Festival. His project first appeared in 2014.
Using an assemblage of spare parts and plenty of engineering know-how, he has pieced together a full-color FDM 3D printer.
The machine follows the color principles of 2d printing – that cyan, magenta, yellow and black (key) can combine to create any other color. His linear delta-style printer can print any hue. Unlike traditional 2D printing though, the absence of paper means the Arcus 3D Printer requires white filament too. Hence, CMYKW.
Over time, the machine evolved from a junkstrap build, into a “full color capable linear delta 3D printer”, described now as an “ongoing effort to perfect a reliable active mixing filament printer.”
The Arcus 3D Printer is pieced together from an eclectic collection of parts. Among other things, it uses a CRAMPS board — based on BeagleBone Black, with Machinekit and custom code — plus Bowden tubes taken from an old mig welder and screen door rollers fitted with roller-blade bearings.
Perhaps most interesting of Schwenke’s build is the mixing process.
The Five filaments are drawn toward a liquid-cooled cold-end. From there, Schwenke’s project page describes the mixing:
“The all metal hot-end employs a tiny impeller located right at the melt-zone of the 5 distinct incoming plastic streams. The impeller spins at a relatively high speed and is designed such that it also generates its own extrusion pressure to feed the nozzle. This greatly reduces the feed pressure required, eliminates feeding back into idle ports, dramatically improves color change performance, and helps to mitigate ‘oozing’.”
The results certainly sound impressive. The color change occurs in 20mm of extrusion at 0.4mm. This means a full change between any ratio of mixes between the 5 loaded filaments.
Prints that use mixed color are a known entity to us at this point. Some machines print in full color from the get go. But for FDM, it has taken time to mature (though we will be seeing a lot more of mixed color FDM later in the year).
There are existing color-mixing systems, like the Kickstarted — and yet to ship —RoVa4D. But to see it from workshoppers sharing stuff on GitHub and documenting the build is pretty rad.
