Never buy a printer without seeing it complete a test print.

: This standard 3D model reveals issues with cooling, overhanging, and dimensional accuracy.

: Inspect the aluminum extrusions for dents or bends. A dropped frame can lead to permanent misalignment that software leveling cannot fully fix. The Ultimate Litmus Test: The Stress Print

: Shake the print head and bed gently. Any play or "slop" indicates loose eccentric nuts or worn-out wheels that need immediate adjustment or replacement.