Rapid Prototyping // 2014 PLA, Limit Switch(2), Arduino
One of the major roadblocks to the successful adoption of 3D printing in mainstream consumer and industrial culture remains the high marginal cost of printing parts relative to traditional manufacturing techniques. In the summer of 2014, I began to develop an Arduino based device to take waste product (PLA plastic, a biodegradable plastic produced from corn starch) and turn it into recycled filament for use with consumer and industrial grade 3D printers. Low cost 3D printing promotes larger, more diverse maker communities, both in terms of socio economic status and field of study. Along with reducing the high cost of 3D printing my research reduced waste associated with the rapid prototyping process. This included residual material, support material left over from the 3D printing process, and failed 3D prints.
REprint is comprised of modular stations. First recycled PLA is pulverized into a fine grain. Next, granular plastic is poured into a hopper, heated and extruded. Once extruded the pliable filament is fed into the second station and pulled by motorized urethane rollers. The urethane rollers are soft enough to pull filament without flattening it. The filament is pulled through a cooling system. The cooling system is comprised of a simple Peltier. Filament then travel towards a spool. The spool is connected to a stepper motor that rotates based upon the rate of extrusion. Using limit switches, the stepper motor turns the spool at rate equal to the rate of extrusion, ensuring that the filament has a consistent diameter. A weight sensor tells the extruder when to stop and system shuts off.