RatRig V-Minion

The RatRig V-Minion is an FDM 3D printer from RatRig with a 180 x 180 x 180 mm build volume.

Specifications

The RatRig V-Minion is a premium, compact Cartesian DIY 3D printer kit launched in 2021. It represents one of RatRig's most innovative designs, combining a cantilever Z-axis configuration with exceptional structural rigidity. Instead of utilizing cheap plastic V-wheels or thin aluminum extrusions, the V-Minion is built on heavy-duty linear guide rails and thick structural profiles, turning it into a highly precise and rapid "pocket rocket" of the desktop 3D printing space.

• Hotend: The printer kit does not ship with a pre-configured hotend. Instead, it relies on the compact version of the modular EVA toolhead system (typically EVA 2 or EVA 3 adapted for V-Minion).

Calibration

Tuning the Klipper-based V-Minion requires a calibration process focused on structural squareness and dynamic motion compensation.

• PEI Sheet Degreasing: Clean the PEI build plate with 99.9% Isopropyl Alcohol (IPA) before every print.
• Expected result: Complete removal of hand oils and dust, ensuring maximum first-layer adhesion during high-acceleration print runs.
• Tip: If you are printing TPU, clean the PEI sheet with Windex instead of alcohol.

Common defects

Despite its robust design, the V-Minion has specific hardware vulnerabilities and software configuration quirks.

• Hardware defects and mechanical weaknesses
• Y-Axis Inertia and Bed Weight: As a bedslinger, Y-axis acceleration is limited by the mass of the print bed and the printed model. Printing heavy parts (exceeding 500g) increases Y-axis inertia, which can cause layer shifting under aggressive acceleration. Limit Y-axis acceleration to 5,000 mm/s² for heavy prints.

What it is used for

Excellent Use-Cases:

• Rapid Small Parts Prototyping: Perfect for printing small brackets, gears, and custom electronic housings in ABS, ASA, and PLA.
• Flexible Filament Printing: The direct-drive extruder setup on the toolhead handles soft flexible filaments (TPU) with ease, making it suitable for printing custom gaskets and dampeners.