for Bambu Lab Extruder Gear Assembly - H2S

The Extruder Gear Assembly precisely advances and controls filament movement, ensuring smooth printing and enabling filament changes when required.

 Installation

Please learn about the installation on Bambu Lab Wiki.

In the Box

- Extruder Drive Gear*1

- Extruder Idler Gear*1

- Shim Washer*1

- Compression Washer*1

- Compression Spring*1

- M3-11 Screw*1

 Compatibility

H2S and H2S Laser

Replace H2S Extruder Gear Assembly

Precautions:

Please be sure to follow the disassembly sequence outlined in this article strictly. Especially before removing the cover of the extruder, make sure to first remove the extruder filament sensor (handle with care to avoid pulling too hard), as failure to do so may result in the wiring of the sensor broken.

When to Use

Extruder gear failure.

Tools and Materials Needed

New extruder gear

Allen keys H2.0 and H1.5

Double-sided tape (recommended)

20 minutes

Screw List

Screw A: 2 screws for the filament sensor, BT2x6

Screw B: 4 screws for fixing the extruder unit front cover, BT3x8

Screw C: 1 screw for the cutter handle, BT2.6x14.5

Screw D: 1 side screw for the extruder, BT3x12

Safety Warning

IMPORTANT!

Before performing any maintenance on the printer or its electronic components (including toolhead cables), turn off the printer and disconnect the power supply to avoid short circuits, which may cause damage to electronic devices and safety hazards.

When maintaining or troubleshooting the printer, first check the temperature of the hotend and heatbed. Avoid operating at high temperatures. If high-temperature operation is necessary, wear heat-insulating gloves to ensure safe and effective maintenance.

If you have any questions about this guide, please click to submit a service ticket, and we will respond promptly to provide the help you need.

Disassembly Instructions

Step 1: Remove the Hotend

Refer to this tutorial to remove the hotend.

Step 2: Disconnect the PTFE Tube

Press the pneumatic connector to disconnect the PTFE tube;

Step 3: Remove the Rotating Wheel

Rotate the rotating wheel and take it off.

Step 4: Loosen the Cutter Handle

Hold the cutter handle and use a screwdriver to remove 1 screw. After the screw is fully removed, gently release the cutter handle and let it hang naturally.

Step 5: Remove the Filament Sensor

Use an H2.0 Allen key to remove 2 screws. If possible, attach double-sided tape to the top of the toolhead to place the filament sensor, preventing it from falling during subsequent disassembly and assembly. Note: Do not pull hard when removing the filament sensor, and handle it carefully to avoid damaging the black FPC cable.

Step 6: Remove the Extruder Unit Front Cover

Use an H2.0 Allen key to loosen the tension driven lever locking screw on the side by one full turn;

Use an H2.0 Allen key to remove the 4 screws on the front cover.

Remove the extruder unit front cover.

Step 7: Remove the Driven Wheel Bracket

Use an H2.0 Allen key to remove the side screw. The internal spring and end cap may easily fall off when removing the bracket, so handle it carefully to prevent loss.

Step 8: Remove the Extruder Gear

Gently shake the large extruder gear and pull it out directly.

Assembly Instructions

Step 1: Install the Extruder Gear

Install the extruder gear.

Step 2: Install the Driven Wheel Bracket

Mount the driven wheel bracket onto the corresponding rotating shaft. Assemble the spring and end cap in the correct orientation and position (refer to the correct and incorrect examples below), place them in the corresponding position on the driven wheel bracket, and screw in the side screw to hold them in place—do not fully tighten yet.

IMPORTANT!
Ensure the spring and end cap are installed correctly; otherwise, the extruder may fail to grip the filament, leading to printing errors.

Left: Correct demonstration, with the screw pressing against the concave surface of the end cap;

Right: Incorrect demonstration, with the end cap in the wrong position, preventing the spring from being compressed.

Pre-lock the side screw by 2-3 turns—do not fully tighten, as this may hinder front cover installation.

Step 3: Install the extruder unit front cover

Reattach the extruder unit front cover and screw in the 4 front cover screws.

Tighten the extruder side screw;

Step 4: Install the filament sensor

When installing the extruder filament sensor, make sure the black FPC cable is not bent and is placed smoothly into the gap. Then fasten the extruder filament sensor with 2 screws.

When assembling, be careful not to pinch the sensor cable. Use your finger or a plastic tool to move the cable away from the screw holes. Before tightening the screws, check the holes from the top to ensure the cable is not blocking them.

Step 5: Reattach the Cutter Handle

Before re-tightening the screw, hold the cutter handle firmly in position. When tightening the screw, avoid excessive force to prevent thread stripping.

Step 6: Connect the PTFE Tube

Insert the PTFE tube.

Step 7: Reinstall the Rotating Wheel

Reattach the rotating wheel.

Step 8: Install the Hotend

Refer to this tutorial to install the hotend.

How to Verify Completion/Success

Turn the printer back on and control filament filamenting and retraction via the screen to confirm proper operation.