Common knowledge leads us to believe that commercial 3D printers produce stronger, more durable components, but research from Michigan Tech suggests that some RepRap style printers can produce stronger components. Michigan Technology University has already proved that low cost, RepRap 3D printers can produce open source lab equipment, as well as saving consumers a significant amount of cash over the printers lifetime.

The study has been published in Materials and Design and is titled “Mechanical properties of components fabricated with open-source 3D printers under realistic environmental conditions.” In the study, the researchers tested the tensile strength and modulus of elasticity of objects printed by both commercial and RepRap printers. They used “a variety of open-source 3D printers including an original Mendel RepRap, a Prusa Mendel RepRap, a Lulzbot Prusa RepRap, and a custom MOST RepRap.” Three different slicing software’s; Skienforge, Slic3r and Cura were used.

Dr. Joshua Pearce from Michigan Tech explains  “RepRaps could print parts that look identical to plastic prints from professional 3D printers that cost 10s or even 100s of thousands of dollars, but there was a concern among engineers and the general public that the low-cost printers could only print flimsy plastic trinkets. We were curious too. Our prints seemed strong, but we wanted to engineer robust scientific equipment and tools for the developing world, so we needed solid trustworthy numbers.”

ABS tensile test

The team found that the average tensile strengths of ABS and PLA were 28.5MPa and 56.6MPa respectively. The average elastic moduli of ABS was 1807MPa, while PLA was 3368MPa. They also found that values varied depending on the layer height and print orientation.

Pearce said  “The results of the study are clear – parts printed from tuned, low-cost, open-source RepRap 3-D printers can be considered as mechanically functional in tensile applications as those from commercial vendors. In many cases they were actually stronger than the results reported in the literature.”

Michigan Tech researchers still need to conduct further research to find out how well RepRap 3D prints stand up against more expensive machines. “This study only looked at the tensile strength in the plane of the print bed, next we need to expand this study to look at interlayer adhesion.”

Still, if you thought that cheap RepRap machines couldn’t produce anything useful, Michigan Tech has proved that they can print fairly strong components.