Voron Clicking Extruder — Causes, Fixes, and Prevention

Troubleshooting Extruder

Causes of Extruder Clicking

The clicking sound from your extruder is the sound of the drive gear slipping against the filament — it is trying to push filament forward but encountering resistance. Here are the most common causes in order of likelihood:

• Nozzle too close to the bed — Creates backpressure. The extruder cannot push filament against the pressure, causing the gear to skip back. This is most obvious on the first layer.
• Hotend jam / partial clog — Debris or degraded filament inside the nozzle restricts flow. The extruder pushes but meets resistance.
• Heat creep — Heat travels up the heatbreak, softening filament before it enters the melt zone. The softened filament deforms instead of feeding, causing the gear to lose traction. More common on long prints.
• Extruder tension too tight or too loose — Too tight crushes filament causing it to deform and skip. Too loose cannot grip, allowing slip under load.
• Idler bearing not spinning — A stuck idler bearing creates drag. The filament must overcome bearing friction, causing the drive gear to skip.
• Drive gear worn out — Worn teeth cannot grip filament. This is a wear item — replace after 500-1000 hours of printing depending on filament type (glow-in-the-dark and CF filaments wear gears quickly).
• Filament diameter variance — Wide spots in filament (1.75mm + 0.10mm) create intermittent resistance. Cheap filament is a common culprit.
• PTFE tube gap (V6-style hotends) — If the PTFE tube does not butt firmly against the nozzle inside the heatbreak, a gap forms where molten filament pools and clogs. This is a design flaw of V6 hotends, less common on Voron-recommended hotends like Dragon or Rapido.

Diagnostic Steps in Order

1. Rule out the first layer — If the clicking happens only on the first layer, the nozzle is too close. Babystep Z up by 0.02mm and re-test.
2. Verify retraction — Excessive retraction pulls molten filament into the heatbreak where it cools and jams. Try reducing retraction by 0.5mm and see if clicking stops.
3. Check filament path — Remove filament from the extruder and see if it slides freely through the PTFE tube to the hotend. Binding in reverse bowden or filament guide can cause clicking.
4. Cold pull test — Perform a cold pull to check for debris in the nozzle. If the cold pull comes out clean with a perfect nozzle tip impression, the hotend is clear.
5. Temperature tower — Print a temperature tower to find the optimal printing temperature for your filament. Printing too cold causes high backpressure that clicks.
6. Extruder disassembly — Inspect the drive gear for wear, check the idler bearing spins freely, and verify tension is appropriate.

Fix for Each Cause

• Nozzle too close: Raise Z-offset by 0.02-0.05mm. Re-run first layer test.
• Hotend jam: Heat to filament melting temp, use a cleaning needle (0.35mm for 0.4mm nozzle). If that fails, cold pull with nylon filament at 90-100℃.
• Heat creep: Ensure hotend fan is always on in Klipper config (heater_fan my_hotend_fan with no temperature trigger that turns it off). Check fan is spinning at full speed. Reduce chamber temperature by opening enclosure panels if needed.
• Tension adjustment: On CW2, the tension screw should be tightened until filament barely grips when pulling gently, then one additional quarter turn. On Galileo 2, check the cam tension lever is in the correct position for your filament diameter.
• Idler bearing: If the bearing does not spin smoothly, clean or replace it. A worn bearing creates drag and causes intermittent clicking.
• Worn gear: Replace the drive gear. Bondtech gears should be cleaned regularly (see below).
• Filament variance: Switch to a higher quality filament brand. Use calipers to measure filament diameter at multiple points — reject rolls with variance > 0.05mm.
• PTFE tube gap: Disassemble the hotend, ensure the PTFE tube is cut perfectly square and butts firmly against the nozzle. Use a fresh section of PTFE tube if the current one is deformed.

Prevention Tips

Proper Retraction Settings by Hotend Type

Excessive retraction is the #1 cause of heat-creep-related clicking. Use these retraction ranges as starting points:

• V6 with PTFE liner: 3-5mm at 30-40mm/s
• Dragon standard flow: 1-2mm at 30mm/s
• Dragon high flow / Rapido: 0.5-1.5mm at 30mm/s
• Revo (all types): 0.3-0.8mm at 25-30mm/s. Revo is extremely sensitive to retraction — max 0.5mm recommended.
• Mosquito / Goliath: 0.5-1.5mm at 25-35mm/s

Filament Drying

Wet filament expands when heated, creating steam and backpressure inside the nozzle. This causes clicking, popping, and oozing. Dry filament before use: PLA at 45-50℃ for 6 hours, ABS at 65-70℃ for 8 hours, PETG at 65℃ for 8 hours, Nylon at 70-80℃ for 12+ hours.

Cleaning the Nozzle

Heat to 250℃ (PLA) or 280℃ (ABS). Wipe the nozzle tip with a brass brush or wire brush to remove carbon deposits. Then extrude 50mm of filament to flush any debris out.

Extruder-Specific Fixes

Clockwork 2 (CW2) Clicking Fixes

CW2 is the most common Voron extruder. Check: idler tension screw, idler bearing free rotation, drive gear wear on the stepper motor shaft. The standard CW2 tension screw should start flush, then tighten until filament is gripped. Over-tightening causes the filament to deform and click.

Galileo 2 Clicking

Galileo 2 uses a planetary gear system. Clicking often comes from: incorrect cam lever position (use the 1.75mm position), debris in the spur gears, or bearing wear in the planetary system. Disassemble and grease the planetary bearings with PTFE grease if they feel rough.

Orbiter Clicking

The Orbiter extruder is sensitive to filament path alignment. Ensure the PTFE tube is not bent sharply at the extruder inlet. The gear mesh tension is factory-set and usually not adjustable. Clicking usually indicates a hotend issue (clog, temp too low) rather than the extruder itself.

Temperature Tower to Rule Out Hotend Issues

Print a temperature tower to determine the optimal printing temperature. If clicking happens at lower temperatures but stops at higher ones, you are printing too cold. If clicking happens at all temperatures, the issue is mechanical (clog, gear wear, tension).

Bondtech Gears Cleaning Process

Bondtech drive gears accumulate filament residue over time, reducing grip. Cleaning process:

1. Remove the extruder from the toolhead.
2. Take out the drive gears by removing the C-clips and bearing.
3. Soak gears in isopropyl alcohol for 10 minutes.
4. Scrub with a brass brush (do not use steel — it damages the gear teeth).
5. Rinse with IPA and dry with compressed air.
6. Reassemble and re-grease bearings.

Clean gears every 100-200 hours of printing for consistent performance.