3D Printer SDM

Another project that I started recently aims to increase the material efficiency, versatility, and accessibility of SDM (Shape Deposition Manufacturing) using a 3D printer. Conventionally, SDM is performed with coarse material deposition followed by a milling operation for each material layer or using high precision casting and an abundance of sacrificial materials. Multimaterial 3D printers exist already (such as the Objet Connex Series) but they are prohibitively expensive, and are not designed to accommodate embedded actuators or sensors.

This project is based on work done by the Fab@home project out of Cornell  University as their printer is already multi-material ready. The downside is that the stock printer deposits material using small syringes which severely constrains the build size without multiple refills. A dual ABS/PLA and EVA extruder has been designed to provide the continuous performance necessary to investigate shape deposition manufacturing.

The printer can be seen here in a well ventilated section of my room(!):

The ABS extruder is working very well, but the EVA extruder needs a redesign as the extrusion material melts way before it even reaches the nozzle because of inadequate thermal insulation. A sample part was printed in ABS and then manually filled in with EVA to test cohesion and material property based joint emulation.