Many desktop 3D printer users are accustomed to buying large rolls of filament. So far, there haven’t been a lot of innovations with regard to how raw plastic material might be fed into the extruder. However, in a recent blog post, Richard “RichRap” Horne discusses how he wants to change things up, by ditching the rolls of filament for plastic pellets.
There have been a few printers, such as Sculptify’s David, which have also utilized pellets, but none have been open source. As always, RichRap wants to maintain his project as part of the open-source community. So, all of the files for his Universal Pellet Extruder can be found on Youmagine.
Printing with pellets offers quite a few benefits. Currently, 3D printing filament is produced by melting down plastic pellets, extruding the melted plastic into a thin circular shape, and then rolling it up into spools. Using pellets, however, eliminates the need for further processing, and, therefore, makes them much cheaper. Fewer manufacturing steps also helps to minimize the chance of material contamination, so prints will be more consistent. On top of all of this, plastic pellets are currently used in industrial injection molding machines, so there’s already a much wider selection of plastics available.
RichRap experimented with a few different sources for pellets, and even tried to reuse filament by cutting it up into tiny pieces. In the end, he found the easiest and best source to be pellets from ColorFabb.
In order to help make the extruder easy to build for Makers all around the world, RichRap kept the parts list fairly simple. The majority of the extruder is composed of 3D printed parts, and a reliable J-Head MK3 was used for the hotend. The pellets are fed into it by a modified 6mm wood auger bit, which is driven by the extruder’s stepper motor. Other than that, the only necessary parts are some M3 and M4 fittings, and standard 606 bearings.
RichRap closes his blog post by reaching out to the Maker community:
This is a very exciting project, do let me know what you think about it, all and any feedback is good. And if you decide to make one or want to evolve the design, please feel free and spread the word.