H2D H2C H2S Z-Banding & VFA Test Tower (Square)

This model is a diagnostic test tower designed to clearly reveal Z-banding and Vertical Fine Artifacts (VFA) on FDM 3D printers, using flat surfaces instead of cylindrical geometry.

Unlike round models, this version features four flat walls, making it even easier to spot repeating patterns, ghosting, and directional artifacts under proper lighting.

Note: please find my other cylindrical model, it's worth to do both tests.
 

What this model helps you detect:

• Z-banding (Z-wobble): horizontal lines caused by lead screw issues, misalignment, or inconsistent Z movement
• VFA (Vertical Fine Artifacts): fine vertical patterns often linked to belt tension, motor resonance, or motion system imperfections
• Directional artifacts: differences in surface quality between X and Y axes

Why this design works:

• Flat walls make surface defects more visible than curved ones
• Sharp edges help identify ringing and motion-related artifacts
• Tall structure amplifies repeating patterns over height
• Simple geometry removes distractions from analysis

Recommended print settings:

• Use your standard profile first (baseline test)
• 0.2 mm layer height (or your typical setting)
• 2–3 walls
• Low or no infill
• Print at normal speeds to reflect real conditions

Tips for best results:

• Inspect walls under angled (side) lighting
• Rotate the model between prints to compare axis behavior
• Test different speeds, accelerations, and jerk settings
• Compare before/after mechanical adjustments (belts, lubrication, alignment)

This version is especially useful for diagnosing axis-specific issues and is a great complement to cylindrical test models.