A RecycleBot is a waste plastic extruder that creates 3-D printer filament from waste plastic and natural polymers. This is a fully automated version of Recyclebot v2.2 with many improved features. For more info see C. Baechler, M. DeVuono, and J. M. Pearce, ?Distributed Recycling of Waste Polymer into RepRap Feedstock, Rapid Prototyping Journal, 19(2), pp. 118-125 (2013). open access For similar see the Open-Source Lab How to Build Your Own Hardware and Reduce Research CostsThe mechanical design is equivalent to RecycleBot v.2.2 http://www.thingiverse.com/thing:12948 - I strongly recommend reading that first. This design is, of course, far from optimized particularly with respect to cost and DYI, it is primarily being used by the Michigan Tech in Open Sustainability Technology Research Group to make new fucntionalized 3-D printing materials (e.g. electrically conductive) to support a full range of products open-source disributed manufacturing...lots more to come. Some of the improved features over RecycleBot v2.2 are: The energy performance of v2.2 can also be significantly improved with insulation. Heating Zone As the heater is the most important section it must be designed and fabricated precisely for better results as changes in temperature of few degrees can result in different mechanical properties of the extruded plastic. Another important criteria for the heating section is to create uniform heating environment so that the temperature remains nearly constant throughout the barrel such that the extruded plastic is uniform. To achieve this, high temperature ceramic beads were used to insulate the bare nichrome wire so as to achieve electrical isolation from the iron barrel, and an advantage of using this scheme is high-quality thermal insulation from the ambient environment and heat transfers efficiently to the iron barrel as the bottom side of the ceramic beads rest on the metal tightly and the top surface is insulated to the air, which is then insulated as well. Steps to make the heater section Safety note use gloves while using furnace cement as its alkaline in nature and can injure you and damage the skin if exposed for a prolonged time, if by chance skin comes in contact with furnace cement, then wash it under running water immediately. It is recommended that you do this in a hood if you have access to one. Temperature Monitoring and Process Control Controlling the temperature and other related processes of plastic recycling and extrusion in an efficient manner and simultaneously decreasing the cost is the key challenge for RecycleBot development especially for home applications. In order to promote the RecycleBot for open sustainability, the whole control system is designed to work on Arduino, which is a very popular open source microcontroller based application development platform. Being easy to use and program with excellent user community support, Arduino is a low cost rapid prototyping platform ideal to implement control system for RecycleBot. Arduino Mega was used to design and implement the system, having enough input/ output pins for interfacing LCD, keypad, and other components. The whole process is divided into two parts: Input mode and Control mode Input mode The process starts with user input of either plastic selection or extrusion temperature. With the option of 10 different types of plastic, user can select the desired type of plastic to recycle and the program automatically loads the optimum temperature range for operation/ extrusion for that particular type of plastic. Alternatively, user can also feed the temperature of extrusion for any type of plastic which can be operated below 350C. After the extrusion temperature is set, program ask the user to confirm the temperature and once the temperature is set, the program steps into the control mode. Control mode In the control mode, the microcontroller is taking the temperature as input and adjusting the output power of heater accordingly such that temperature remains within the set bound range which is 15C above and below the set extrusion temperature. The system is designed in such a way that if by any means the system temperature exceeds the set extrusion temperature, the power of the heater is cut off completely until the system temperature gets within the set bound range. Also, when the temperature is within the set range, the extrusion process starts, i.e. the motor starts feeding the shredded plastic from the hopper to the heater, also the spooler stepper motor starts which wind up the filament and coil over a spool. If the temperature drops 15C below the extrusion temperature, the program stops the feeder motor as well as the spooler motor to ensure that the quality of filament remains the same, and as soon as the system temperature reach the set range of operation, both the feeder and spooler motor resumes working. Program Code The code for RecycleBot was written by Michigan Tech graduate student Ankit Vora at in C on Arduino IDE, using the keypad, LCD and stepper motor libraries. In order to replicate the RecycleBot code on an Arduino Mega, first, all the libraries must be copied into the correct destination of Arduino folder such that Arduino compiler can compiler them along with the program code. On Arduino development platform LCD library is already included, however keypad and stepper motor library need to be registered before compiling the code. Steps to replicate, compile and upload the program code on Arduino Mega (if you are using a new version of Arduino, then copy all the libraries to that folder, in any case the folder of Arduino development platform will be having folder 'libraries' and each and every library used must be copied to this folder. If you have trouble with the files send me an thingiverse mail or email Ankit at avora#mtu.edu (replace # with @, anti-spam) RecycleBot Circuit Download the circuit diagram and fabricate on two separate PCBs in order to get better reliability. One can use a breadboard, but using breadboards sometimes creates reliability issues due to hanging wires, and especially when we are using high power control elements with low power DC control and monitoring components, its better and recommended to make the circuit on general purpose PCB for rapid prototyping. It is recommended to make the temperature sensor and measurement circuit on one PCB and DC motor and heater controller on another PCB. The circuit for temperature sensor is small and works on low voltage of +5 V and needs a good isolation for the AC components and must be fabricated on a separate PCB as shown in the picture gallery. And the circuit for DC motor control and heater controller uses both +5V, +12V and 110V AC, so it must be well isolated from the low voltage DC components like Arduino etc., so that the transients, spikes won't affect the working of temperature and process control, hence it must be also fabricated on a separate PCB. Use good quality copper wire for heater power controller such that it can withstand both high power and temperature. For a more indepth description including how the circuit works, and how to assemble everything, and costs see this There are also lots of other cool RecycleBot-like devices - see for example: Filabot http://www.thingiverse.com/thing:24583 Lyman http://www.thingiverse.com/thing:34653 Lyman also has a spool winder -- which you will likely need depending on what type of plastic you are using: http://www.thingiverse.com/thing:30705