BLV MGN Cube 350

The BLV MGN Cube 350 is an FDM 3D printer from BLV with a 350 x 350 x 350 mm build volume.

Specifications

The BLV MGN Cube 350 is one of the most successful and robust open-source DIY 3D printer projects, designed by Ben Levi. As a self-assembly project (DIY kit or BOM list), the final hardware configuration can vary depending on the components selected by the builder. The project was conceived to address the weaknesses of traditional acrylic and aluminum "bed-slinger" printers by providing an exceptionally rigid, cubic frame paired with precise linear motion.

• Hotend: Extremely flexible mounting interface. It is typically configured with an E3D V6 nozzle, a Volcano hotend for high-speed extrusion of thick layers, or a high-end Mosquito/Dragon hotend.

Calibration

Unlike commercial pre-built printers, the DIY nature of the BLV MGN Cube requires a rigorous engineering approach to calibration. Mechanical assembly errors cannot be fully corrected by firmware modifications. Follow these 8 crucial steps:

• Squaring the Frame: Before mounting any linear rails, verify that the aluminum frame is completely square. Measure diagonals across the top, bottom, and side faces of the cube; they must match within fractions of a millimeter.

Common defects

• Hardware defects and mechanical weaknesses
• Z-Axis Drop with Trapezoidal Screws: In the original design, using standard T8 lead screws without anti-backlash nuts allows the heavy bed assembly to drop under its own weight when the motors are de-energized. During prints, this can introduce Z-banding. Solution: Install spring-loaded POM anti-backlash nuts or upgrade to a Belted Z-axis design.

What it is used for

Best use-cases:

• Large-Format Functional Prototyping: Ideal for printing full-sized enclosures, architectural models, and automotive components up to 350 mm. The stationary bed prevents part wobble, allowing tall, slender prints to succeed where bed-slingers fail.