RigidBotBig

The RigidBotBig is an FDM 3D printer from RigidBot with a 300 x 400 x 254 mm build volume.

Specifications

The RigidBot Big (also known as the RigidBot Regular-Big or RigidBot Regular-X) is the expanded-volume variant of the classic RigidBot, released by Invent-A-Part (later RigidBot, LLC) following their highly funded 2013 Kickstarter campaign. This model was developed to provide an exceptionally large build volume for desktop users, pairing the rigid interlocking steel tube frame with a massive build plate. However, the sheer size of the print bed introduced severe electrical and thermodynamic challenges that made the printer unreliable in its stock factory configuration.

• Hotend: Equipped with a proprietary Bowden-style extruder and a 0.35 mm brass nozzle.

Calibration

Configuring and maintaining the RigidBot Big requires a hands-on approach to manage the moving mass and electrical loads:

• Installing an External MOSFET Module: Sourcing high current for a 300 x 400 mm heated bed directly from the motherboard will destroy it. Install a dedicated external MOSFET rated for at least 30A. Wire the control signal from the motherboard to the MOSFET gate and run the main power line directly from the power supply to the bed heater through the MOSFET.

Common defects

• Hardware defects and mechanical weaknesses
• Motherboard Bed Terminal Meltdown:
• Symptoms: Burning plastic smell, heated bed failing to warm up, and charred or melted power terminals on the motherboard.
• Cause: The large 300 x 400 mm bed draws 15A–18A at 12V. The factory terminal blocks on the motherboard are not rated for this continuous current, leading to extreme heat generation.
• Solution: Use an external MOSFET module.

What it is used for

Recommended Applications

• Large-Scale PLA Layouts: The spacious 300 x 400 mm bed is well-suited for printing large display models, organizers, and architectural layouts in a single piece.
• DIY Retrofitting Projects: The rigid steel frame provides an excellent base for building a custom large-volume printer with Klipper, a 24V conversion, and modern 32-bit electronics.