The accumulation of plastic waste is a global environmental problem. It is estimated that approximately 8 million tons of plastic waste will enter the ocean every year. In order to make a global difference we must change the way we look at plastics and with that in mind Arcada University of Applied Sciences and 3DBear have teamed up for this project to develop a solution.
Introducing our team and the 3DBear Recycler!
Jan-Peter Holm, Hardware Lead Paul Nix, Recycling Specialist
As the world changes to embrace new technologies like 3D printing, and new problems like resource scarcity and waste accumulation, 3DBear is looking into the future. Our open-source recycler project is a student-led initiative meant to change the way we look at plastic waste in our communities, while providing a resource to the growing local ecosystem of 3D printers and makers among us. It is time to embrace the circular economy, by considering modular grassroots methods of resource management, and 3DBear is here to help.
This is the 3DBear open-source recycler. Using it you can easily take existing and failed 3D prints, and filament scraps, as well as other plastics, and recycle them into new usable 3D printer filament. Fully spooled and ready to use.
If you've looked at other extruding devices you will have seen two major problems; first these devices are expensive, and secondly they produce inconsistent filaments that can jam 3D printers or cause prints to fail. There is no reason that 3D printing cannot be sustainable and efficient.
We want to provide an extruder option that produces consistent results, and with optical sensors controlling our puller/spooler you know your filament will be precisely what you need. Additionally the 3DBear recycler has the capacity to refill your spools quickly and can easily keep up with the filament needs of a community of 3D printers.
Our goal is to provide our full assembly, control code, custom part designs, and parts list, to anyone in the world who wants to make their own filament. We want labs and workshops around the world to interact, send pictures, and updates of their own unique recycler builds, to streamline design options and inspire innovation. Furthermore we want each new recycler to bind local schools, libraries, and makerspaces into grassroots communities that can support one another as we move into a more sustainable localized economy, together.
The Parts list
Here we include a detailed list of any and all parts that can be purchased directly or ordered online along with a description of quality variants and DIY alternatives for some parts, so that each maker can customize their build for their own budget and needs. This list will include mention of the companies that we used to fabricate the screw and barrel as well as the main logic board as these firms are already tooled up to produce these parts. Our initial sources should act as a good starting point, but may not be the best fit for everyone; as we built this prototype in a school in Finland, many of our sources reflect this region and might be more easily accessible elsewhere.
The custom parts files
Here we include our solidworks files of most of our components, .stl files of 3D printable parts, source code for the Teensy, and files for custom fabrication of the main board, as well as machine drawings of our screw barrel and hot ends for fabrication.
Assembly and subsystems
Below we detail the primary systems of our device: The logic system, the heating system, the extrusion system, the frame assembly, and the spooler system.
The Logic System
The processing center of the device, containing motor controllers and the Teensy chip, taking data in from the optical sensors and motors and outputting the appropriate speed adjustments to maintain optimum filament diameter. Control of all of the other active systems can be routed through the logic system so that one switch will turn the system on and once the system is up to temperature extrusion will start. This system also includes the display board at the front of the device that currently gives live readings of the amount of material extruded in length and the current live diameter of the filament, this LCD display is easily customized.
The Heating System
The heating system consists of heating bands, PID controllers, solid state relays, and thermistors which regulate the generation of heat to bring the barrel and hot end up to the required temperature to mix and melt plastic. The temperature is easily adjusted for a wide variety of plastics. In the end these components end up being in very different parts of the recycler, but you can see each of the parts in the picture to the right.
This includes the screw, barrel, barrel sleeve, hot-end, material hopper, cooling fans, heat sink, and the driving motor and couplers. Essentially this is the heart of the recycler, it is what drives the molten plastic through the recycler. Several components of this system are custom and with have to be manufactured in a machine shop, the screw, barrel, barrel sleeve, and hot end are included as machine drawings and can likely be fabricated locally to you. Several other components were designed to be 3D printed, the .stl and solidworks files are included. Finally the fans are easily scavenged from old PC's and the hopper is made to connect to a standard PET plastic soda bottle, which can be reshaped under heat.
The Frame Assembly
The frame assembly includes the aluminum x-profiles, but also includes all of the 3D printed hammer nuts, rod brackets, cable managers, backer boards, end caps and adjustable feet. The quality on these parts is completely adjustable to the final product you want for your lab or workspace. As you can see it is very simple to add hinges which can attach to polycarbonate doors to restrict access during operation for increased safety. The most important thing for us as we designed this was that the frame and components be adjustable and easily customized to the goals of the group assembling the recycler. Feel like the extruder platform is too low? Raise it up. Want a small footprint, or vertical clearance? Reduce the length of your x-profiles. We want the recycler to continue growing and meeting the needs of the local groups working with it.
The Spooling System
Connected to the frame on 3D printed brackets that can easily be edited for modular customization, the spooler motor attaches to a threaded rod that will turn to pull filament onto the spool. The filament first passes through an optical sensor which gives feedback to the logic system in order to adjust the speed of the puller motor; if the filament is too thin the puller slows down, if it is too thick the puller will speed up. Because the brackets and pulleys are modular and 3D printable, you can continue to customize based on the needs of any plastic blend you may be extruding.
There are systems that can be simplified, upgraded, streamlined or otherwise customized in your own DIY build of the recycler. We have compiled a short list of systems that we will be looking at improving ourselves that you may also attempt to address.
- We have widened the feed intake hole on the barrel to allow easier feed of material. Perhaps the feed can be further optimized.
- The frame is currently significantly larger than required, the device could be made using a much small footprint.
- We have always intended to integrate a proper grinding system, with options for either manual grinding of plastic or automatic.
- We have also looked at revising the heating sleeve so that it will form a cylinder with a shape continuous to the hot-end. That way a single larger diameter heating band can apply heat directly to the hot-end, and the thermistor reading point can be moved from a horizontal position as it is currently to an inverted vertical position into the downward facing surface of the hot-end.
- The 3D printable display backer component which holds the LCD screen can be altered to make room for rear mounting the LCD so that it displays through the display backer.
- The Power backer could be revised into two interlocking 3D printable components that can be printed on a standard smaller print bed.
- Several of our 3D printable designs can be revised to use less material without compromising their mechanical strength.
- Our current design could be altered to bring the spool immediately below the hot end in line with the optical sensor, for PLA this is an ideal distance.
These are just a few ideas that could become full developments for later versions of the recycler. We look forward to your contributions!
Let us know where you are at with your process, send pictures, stories, questions, pitfalls; we'll catalog them here and share your experiences with anyone else going through this process, so that you and they will never be alone.
Email us: Paul(at)3DBear.fi or Jan-Peter(at)3DBear.fi
3DBear has been truly privileged to be involved in a more sustainable future, and we will continue to do so.
Thank you for joining us!
3DBear Recycler Copyright © held by 3DBear Ltd. License GNU GPL v3