New DIY Concrete 3D Printer from Off-the-Shelf Parts

The new M3-Crete is a DIY, open-source, medium-sized concrete printer aimed at researchers, universities, and contractors so they can build, modify, and improve on a validated baseline, but anyone why wants to print their own garden walls and concrete furniture can also join in.

The project, recently uploaded to GitHub, follows the logic of a scaled-up desktop gantry, stretching a 1 m³ workspace over an open-frame architecture. Rather than proprietary rail systems or custom industrial castings, the M3-Crete aims to use standard, off-the-shelf components like NEMA 23 motors, paired with generatively designed printable parts for efficiency and rigidity.

The printing of concrete is not your typical use case for a machine of this type, but the M3-Crete makes sense when you consider that Sunnyday Technologies (Sunn3D) is also responsible for Cemforge, a printable concrete development platform. Being open source, you could, of course, customize the M3-Crete to your own ends, but the core purpose of it as is as an efficient validation platform for custom concretes.

The design makes “heavy use of generative design for printed parts to compensate for the stiffness differences compared to machined aluminum,” says Sunn3D founder Nick Sonnentag. “I’ve been waiting years to apply generative design at this scale, and I’m genuinely interested to see how the community reacts to the carriage and bracket design.”

To deliver the material, the machine uses a progressive cavity pump (PCP). Unlike the geared dual-drive extruders we’re used to in FDM printing, a PCP uses a helical rotor turning to move material. This creates a sequence of small, discrete cavities that “progress” from the intake to the nozzle. In the context of a thick or lumpy material like concrete, it provides a pulse-free, volumetric flow that can handle the high viscosity and abrasive nature of printable cements without the clogging or inconsistent pressure that can come with in auger or piston-driven setups.