Banding (Horizontal Lines)

"Banding" (or "Z-Banding") is a print quality defect that manifests as regular horizontal lines or repeating patterns on the vertical walls of a print.

What Causes Banding?

This problem is generally caused by mechanical inconsistencies in the Z-axis or by fluctuations in extrusion.

---

Causes and Solutions

1. Mechanical Z-Axis Issues

   • Cause: The Z-axis rods or lead screws may be dirty, bent, or poorly lubricated. This causes friction and prevents the Z-axis from consistently moving up by the same small amount for each layer, resulting in some layers being more "squished" than others.
   • Solution: Clean and lubricate the Z-axis rods/screws. Check if they are bent by rolling them on a flat surface. Also, ensure the couplers connecting the motors to the lead screws are tight.

2. Hotend Temperature Fluctuations

   • Cause: If the nozzle temperature is not stable and varies by several degrees, the consistency of the extruded plastic will also vary. Hotter plastic flows more easily, creating a slightly wider line, and vice-versa.
   • Solution: Perform a PID Tune of the hotend. This function, available in most printer menus, adjusts the heating algorithm to keep the temperature as stable as possible.

3. Filament Inconsistency

   • Cause: Low-quality filaments can have variations in their diameter along the spool. A thicker section results in more extrusion (a more prominent line), and a thinner section results in less.
   • Solution: Use high-quality filament with a good reputation for diameter consistency.

   

Illustration of a part with vertical walls that show a pattern of repeating horizontal lines.