Nozzle replacement
Replacing the nozzle on the G1 is a guided procedure triggered directly from the printer display. The built-in CHANGE_NOZZLE macro walks you through each step, positions the printhead automatically, and ensures the barrel is at the correct temperature before you touch anything.
Tools needed
Section titled “Tools needed”- Gold wrench (included in the G1 tool kit) — fits the nozzle hex
- Second wrench — to counter-hold during final tightening
- PTFE tape (teflon tape) — wrap 3 turns around the thread of the new nozzle before installation
- Heat-resistant gloves or a tissue — the barrel stays hot during the procedure
When to replace the nozzle
Section titled “When to replace the nozzle”- Inconsistent line width even after Rotation Volume calibration
- Visible scoring, denting, or wear at the nozzle tip
- Switching to a different nozzle diameter
- After a crash that may have deformed the nozzle tip
Procedure
Section titled “Procedure”Step 1 — Start the CHANGE_NOZZLE macro
Section titled “Step 1 — Start the CHANGE_NOZZLE macro”
From the KlipperScreen display, navigate to Macros and run CHANGE_NOZZLE. The display shows a 5-step guided procedure.
The display shows: “Make sure the plate and nozzle are clean”.
The printhead moves automatically to the centre of the bed — a safe position for working on the nozzle.
Step 2 — Remove the protective ring
Section titled “Step 2 — Remove the protective ring”Remove the ring (protective collar) from around the printhead to expose the barrel and nozzle.
Step 3 — Remove the old nozzle
Section titled “Step 3 — Remove the old nozzle”Unscrew the old nozzle counter-clockwise using the gold wrench.
Remove all old PTFE tape from the threads of the old nozzle (discard it — do not reuse).
Step 4 — Prepare the new nozzle with PTFE tape
Section titled “Step 4 — Prepare the new nozzle with PTFE tape”Before installing the new nozzle, wrap PTFE tape (teflon tape) for exactly 3 turns around the thread. This seals the thread and prevents molten plastic from leaking along the barrel threads.
Step 5 — Install the new nozzle
Section titled “Step 5 — Install the new nozzle”Screw the new nozzle into the barrel by hand (finger-tight). The barrel is still hot — work carefully.
Place two wrenches on the nozzle and wait for the barrel to reach full printing temperature before tightening.
Step 6 — Close the heat cover and tighten
Section titled “Step 6 — Close the heat cover and tighten”Close the heat cover back around the barrel.
Once the barrel is fully heated, tighten the nozzle firmly with the two wrenches. Use one wrench to counter-hold and the other to apply torque — do not overtighten.
Step 7 — Completed
Section titled “Step 7 — Completed”
The nozzle is installed. Follow the prompts on the display to complete the remaining steps of the guided procedure.
After replacement
Section titled “After replacement”After any nozzle change:
- Recalibrate Z offset — the nozzle tip position changes with every nozzle swap. See Z offset and first layer.
- Run bed leveling — run the
BED_LEVELmacro from the display to generate a fresh mesh. See Bed leveling system. - Check Rotation Volume if switching to a different nozzle diameter — the flow characteristics change. See Rotation Volume calibration.
Related notes
Section titled “Related notes”- Nozzle set — available sizes, materials, layer height rules
- Z offset and first layer — recalibrate after every nozzle change
- Bed leveling system — re-level after nozzle change
- Nozzle and barrel clog — if the nozzle is blocked
- Barrel clog purging procedure — full purge when severely blocked
- Rotation Volume calibration — recalibrate flow after diameter change