Voron Z-Banding and Z-Wobble — Complete Fix Guide

Troubleshooting Mechanical Calibration

Z-Banding vs Z-Wobble vs VFA — How to Tell the Difference

Vertical surface artifacts on 3D prints are often confused. Here is how to distinguish them:

• Z-banding — Horizontal lines that appear at very consistent, evenly spaced intervals. The spacing matches the pitch of your leadscrew (typically 2mm or 4mm, but can be 8mm). Each revolution of the leadscrew creates a visible line. The lines are consistent in thickness and location throughout the print.
• Z-wobble — Horizontal lines at irregular intervals that vary in thickness. Caused by a bent or non-straight leadscrew. The wobble is sinusoidal — the line pattern may come and go at different Z heights depending on the rotational position of the leadscrew.
• VFA (Vertical Fine Artifacts) — Very fine, closely spaced horizontal bands (0.5-2mm apart). Not related to leadscrew pitch. Caused by motor resonance, vibration, belt tension issues, or ghosting from the X/Y axes. VFA requires input shaper calibration and belt tension tuning.

Voron Z-Axis Architecture Differences

Each Voron model has a unique Z-axis design, which affects troubleshooting:

• Voron 0.2 — Single leadscrew, driven by a Z motor at the base. The gantry moves up and down on the leadscrew via a brass nut. A single Z motor with no independent leveling. The leadscrew straightness is critical.
• Trident — Three independent Z motors, each driving a leadscrew. The bed moves up and down on three leadscrews. Gantry leveling is done via the bed's Z screws, not the gantry itself. Each leadscrew must be straight and the Z motors must be aligned.
• Voron 2.4 — Belt-driven Z (four independent Z motors with belts). No leadscrews at all. The gantry moves up/down via toothed belts driven by Z motors. Gantry leveling is done via Quad Gantry Leveling (QGL). No leadscrew artifacts, but belt tension imbalance creates Z issues.

Causes of Z-Banding and Z-Wobble

Bent Leadscrew

The most common cause of Z-wobble. A bent leadscrew wobbles as it rotates, translating the wobble into horizontal lines on the print. Roll the leadscrew on a flat surface to check for straightness. Replace if visibly bent.

Misaligned Z Motor

If the Z motor is not perfectly perpendicular to the motor mount (or the frame), the leadscrew binds as it rotates. The coupling compensates for minor misalignment, but excessive offset creates periodic resistance and banding.

Z Motor Coupler Issues

A loose set screw on the coupler (where the leadscrew meets the motor shaft) causes intermittent slip, creating irregular banding. Check both set screws on the coupler are tight against the motor shaft flat and leadscrew. Use threadlocker. A damaged or split coupler must be replaced.

Z Motor Binding at Certain Heights

If the banding appears only at specific Z heights, the leadscrew may have a localized bend, or the brass nut on the gantry may have debris causing binding at that position. Clean the leadscrew with IPA and grease with PTFE or lithium grease.

Gantry Not Square (V2.4)

On V2.4, if the gantry is not perfectly parallel to the bed, the Z belts will rack as the gantry rises, causing banding at different heights. Run QGL (Quad Gantry Leveling) until all Z motors show a repeatable position. If QGL consistently reports high variance ( > 0.05mm), check belt tension and frame squareness.

Z Belt Tension Imbalance (V2.4 / Trident)

On V2.4, uneven Z belt tension causes the gantry to tilt slightly as it rises, creating banding. On Trident, uneven belt tension on the Z motors (which use belts to connect motor to leadscrew on some builds) can cause similar issues. Use a belt tension meter and aim for 110-130 Hz on all Z belts.

Fixes Per Model

Voron 0.2 Fixes

• Replace or straighten the leadscrew. Roll on a flat surface to verify.
• Check the Z motor mount alignment — shim with washers if the motor is not perpendicular.
• Replace the brass nut if it shows excessive wear. Old worn nuts widen the tolerance and amplify wobble.
• Use a flexible coupler (spider coupler or Oldham coupler) between motor and leadscrew to absorb minor misalignment.
• Consider the Belted Z mod (see below) which eliminates the leadscrew entirely.

Trident Fixes

• Check all three leadscrews for straightness individually. A bent leadscrew on Trident causes banding that varies across the bed.
• Verify Z motor alignment — the motor must be parallel to the vertical extrusion. Use a square.
• Ensure the Z bed platform moves freely on its linear rails. Binding on one rail causes that corner to lag, creating banding.
• Run the Trident Z-tilt calibration to level the bed. If the bed is not level, the printer compensates unevenly, leading to banding.

Voron 2.4 Fixes

• Run QGL with high precision. Use QUAD_GANTRY_LEVEL with retries until all motors report positions within 0.02mm.
• Check Z belt tension: all four belts should be at 110-130 Hz on a belt meter. Uneven tension causes the gantry to rack.
• Verify the gantry is square to the frame. Measure the diagonal distances from gantry corners to fixed frame points — they should match.
• Check the Z motor alignment in the motor mounts. The belts should run straight from motor to the Z joint without rubbing.
• Ensure all Z joints (the 3D-printed or CNC parts where the belts attach to the gantry) are not cracked or loose.

Bed Leveling Contribution to Z Issues

A poorly leveled bed creates uneven load on the Z system. On Trident, an unbalanced bed puts more load on one leadscrew, causing that motor to work harder and potentially bind. On V2.4, a poorly leveled gantry (before QGL) puts uneven tension on the Z belts. Always verify bed leveling before chasing Z-banding — a simple leveling issue can mimic banding in the first 10-20mm of a print.

Z Motor Current Tuning

If the Z motor current is too low, the motor can lose torque and skip steps, causing banding. If too high, the motor vibrates excessively, transferring resonance to the leadscrew or belts. For a typical Voron NEMA17 Z motor, set run_current to 0.70-0.80A and hold_current to 0.50-0.60A. For NEMA14 on V0.2, run_current of 0.40-0.50A. Tune within the motor's rated current — check your motor datasheet.

Belted Z Mod as a Solution for V0.2

The Belted Z Mod replaces the leadscrew on the Voron 0.2 with a belt-driven Z system (similar architecture to V2.4). This eliminates leadscrew artifacts completely — no Z-banding, no Z-wobble, and no leadscrew-related binding. The mod uses a toothed belt driven by the Z motor, with a linear rail or guide rod for stability. It also allows quick gantry leveling (Z-tilt adjustment). If you have persistent Z-banding on a V0.2 that you cannot resolve with alignment and coupler adjustments, the Belted Z mod is the definitive fix.