BQ Prusa i3 Hephestos XL

The BQ Prusa i3 Hephestos XL is an FDM 3D printer from BQ with a 200 x 300 x 200 mm build volume.

Specifications

The BQ Prusa i3 Hephestos XL is an expanded version of the popular open-source DIY kit originally developed by the Spanish technology company BQ. This model is modified using the official "long base" expansion kit (XL upgrade package). This upgrade was specifically designed to meet the demands of users wanting to print larger objects along the Y-axis (up to 300 mm) at an affordable price point, while maintaining the classic open-source Prusa i3 frame layout, RAMPS 1.4-based electronics, and 8-bit processing architecture.

Calibration

The larger bed footprint on the BQ Prusa i3 Hephestos XL places higher demands on mechanical assembly. Unbalanced Y-axis inertia can compromise print quality. Execute the following 8 calibration steps:

• Y-Axis Linear Rod Alignment

The two chrome rods for the Y-axis are longer than standard. If the distance between them at the front and back differs by even 0.1 mm, the bed carriage will bind at the ends of its travel.

Common defects

• Hardware defects and mechanical weaknesses
• Y-Belt Slipping Under Acceleration: Due to the weight of the XL glass bed, the stock belt can easily skip teeth on the motor pulley during rapid direction changes, causing horizontal layer shifts.
• Solution: Replace the stock plastic Y-motor pulley with a high-quality 20-tooth metal pulley and manually tighten the belt.

What it is used for

Best use-cases:

• Long Horizontal PLA Models: Well-suited for printing architectural layouts, brackets, cases, and decorative signs up to 300 mm in length.
• Educational Demos of Inertia: Ideal for classroom demonstrations on how moving mass affects 3D print quality.