Introduction

After a laser marking machine has been used for a long period of time, issues may occur—such as the machine failing to mark properly, losing accuracy, producing distorted patterns, or even failing to emit the laser beam. After careful troubleshooting, if you determine that the galvo scanner (vibration mirror) is the cause, you will need to remove it and send it to the manufacturer or an authorized repair center. Later, once the repaired galvo is returned, proper installation is equally important to ensure marking precision and long-term stability.

The following guide will teach you how to safely and correctly remove and reinstall the galvo scanner, along with additional professional tips to avoid damage and ensure optimal performance.

Galvo Removal Steps

01. Always start with complete power-off

Make sure the entire machine is powered off and unplugged.
Disconnect the power connector entering the marking head.
(Some machine models may not have this connector—if so, simply skip this step.)

02. Remove the F-Theta lens and protect it properly

Unscrew the field lens (F-Theta lens).
Important:

• Do NOT touch the optics with fingers

• Keep dust, moisture, or tools away from the lens

• Place a protective cap or clean lens cloth over the optics

Any small scratch or dust particle may significantly affect marking quality.

03. Remove the marking head casing

Use the required tools (usually hex keys) to carefully unscrew the screws on the marking head.
Be gentle—some outer plates may still be connected to the galvo driver board via cables, so avoid pulling too hard.

04. Disconnect all cables

Unplug the following from the galvo system:

• Power cables

• Signal cables

• Motor-to-driver cables

Labeling the cables before removal can greatly help during reinstallation.

05. Remove the driver board and X/Y galvo motors

Carefully take out the galvo driver board.
Then remove the Y-axis motor and X-axis motor.
Pack each component separately with shock-absorbing material.

Once packed, you can send the galvo assembly to your repair center.

Galvo Installation Steps

01. Install the Y-axis and X-axis galvo motors

Place the Y and X galvo motors back into the marking head.
Ensure they do not collide with each other at any angle of rotation.
Motor spacing and alignment are important to prevent mirror interference.

02. Secure the motors firmly

Check that both motors are properly seated and fixed.
Avoid overtightening screws, as excessive torque can affect angle accuracy.

03. Reconnect cables and test alignment

Reconnect:

• Power lines

• Signal lines

• Motor-driver cables

After connection, perform:

• Galvo motor angle calibration

• Depth and offset testing

• Center alignment (laser output must be centered on the field lens)

Precise calibration ensures high-quality marking and prevents distortion.

04. Organize wiring and reinstall covers

Tidy up cable routing to avoid interference with galvo movement and improve heat dissipation.
Reinstall all external casing components.

05. Power on and perform final testing

Reconnect external cables, power on the machine, and perform:

• Galvo scanning speed tests

• Repetition precision tests

• Marking center tests

• Sample marking on metal or plastic

Once everything works normally, the installation is complete.

Additional Professional Tips (Added Content)

Keep the galvo in a dust-free environment

Galvo mirrors are extremely sensitive. Even a tiny dust particle can cause:

• Marking distortion

• Misalignment

• Weak laser output

Use anti-static gloves during operation.

Avoid touching mirrors

Galvo mirrors are front-surface coated and cannot be cleaned like normal glass.

Use the correct software settings

After reinstallation, check:

• Mirror size

• Scan angle

• Field correction file

• Lens calibration data

Incorrect settings may cause serious marking errors.

Check laser path alignment

If the laser is not perfectly aligned with the galvo input aperture:

• The laser may burn the edge of the mirror

• The marking area may deform

• Output power may decrease

A simple red-light alignment test is strongly recommended.

Regular maintenance schedule

To extend lifespan:

• Clean lens exterior weekly

• Check cable stability monthly

• Perform calibration every 6–12 months