Step by step...
Laser Cleaning Torch Repairs  

Clean & accurate laser torches work best and this is the key to the success, take your time, and dont skip any steps

Table of Contents

• POTENTIAL FAULTS & HOW TO FIX
• SAFETY & PRECAUTIONS
• TOOLS REQUIRED
• PROTECTION & FOCAL LENSES
• REFLECTIVE LENS / MIRROR & ALIGNING
• LASER BEAM ALIGNMENT
• SETTING THE FOCAL LENGTH
• COLLIMATING LENS (FIBRE OPTIC TUBE LENS)
• PRE-START CHECKS
• TESTING & CLEANING

1. POTENTIAL FAULTS & HOW TO FIX:

A. Torch heating up (Machine Over-temp Alarm)

1. Misalignment of laser beam
2. Insufficient coolant in water cooler
3. Excessive 'wobble width' causes beam to induce heat into the torch body
4. Dirty protection lens
5. Dirty Focal lens
6. Dirty Y-motor mirror/lens 
7. Dirty X-motor mirror/lens 
8. Dirty collimator lens
9. Dirty fibre optic crystal / lens 


B. Cleaning process not starting

1. Allow more time for the laser generator to start - follow start up procedure
2. No cooling air / gas
3. Wrong settings
4. System faults / errors not rectified
5. Damaged torch lead
6. Insufficient power supply (415V)
7. QBH connection could be loose and the fibre optic is able to move within the torch mount.


C. Power fading

1. The torch is directly in the reflection zone, change the light angle to ensure light reflects elsewhere from the torch.
2. Check your focal length - more detail on this below.
3. Check your input power 
4. QBH connection is loose.

A. Read and understand about laser safety here:
https://www.weldingsupply.com.au/blogs/news/laser-cleaning-welding-safety-precautions-lets-get-real
B. Cleanliness and accuracy is the key to the success of this operation - so take your time, and dont skip steps
C. Turn OFF any fans and operate in a "dust-free" environment without air movement - shut the doors.
D. Make sure the torch is not hot to touch.
E. Disconnect the laser source from power supply
F. Turn off the shielding gas / compressed air.
G. Lay out work tools in your work area
H. Use cable-ties or adhesive tape to secure the laser torch to prevent the torch sliding off the operating table.
I. See diagram below for positions of various subjects refered to in this procedure.

4. REMOVING LENS CASSETTES:

NOTE: These lenses are expensive and fragile.

1. When removing the lens from the torch, remove the thumb screws and slowly slide the lens cassette out half way.
2. Once the lens cassette is half way out, you will see the fixed side and the retaining ring side which can fall out.
3. Reposition your fingers and the torch head to ensure you are holding the retaining ring and the cassette as you remove.
4. Ensure the lens is 100% perfectly clean of particles, dust and soot by using the alchohol & lint free wipes.
5. The Protection lens is flat on both sides and does Not magnify - nearest to the workpiece / outside of the torch. 
6. The FOCAL lens is domed on 1 side and Does magnify - this is very easy to see with naked eye.

All laser consumables can be found here:

5. X & Y MIRRORS / LENS:

1. The reflective mirro lenses are EXTREMELY FRAGILE and can snap / shatter with almost zero impact.
2. Disconnect the laser source from power supply
3. Turn off all fans and shut doors/windows to prevent air/dust movement.
4. Turn off the shielding gas / compressed air.
5. Lay out work tools in your work area
6. Use cable ties or a small weight on the laser torch cable to prevent the torch sliding off the operating table during
7. See diagram above for lens positions

Damaged mirror lens shown below, visible smoke damage (black soot) around base of mirror. 

6. LASER BEAM ALIGNMENT:

1. Laser cleaning torch uses double pendulum motors / actuators to oscilate laser beam to create the beam wobble.
2. Before remounting any motors, ensure the LCD screen Offset is set to exactly Zero (X=0.0 / Y=0.0) not like below image.
3. Place white masking tape or semi-translucent tape over the output hole of the laser torch to allow you to see the visible alignment of the beam.
4. Make sure all lenses and mirror parts are new to ensure no reflection takes place inside the torch, as the light beam MUST pass through without interruption. 
5. The Collimator, Focal and Protection lenses MUST be in place before mounting the mirror motors.
6. Semi-tighten the motor grub screws into position to allow the motors to be manually moved by fingers to align the beam.
7. Once the beam is as near to centre as possible, secure the grub screws fully. Do not use drill to overtighten.
8. If the screws are too loose, the motor positions could move and then melt parts inside the torch or overheat.
8. After the motors have been secured, use the LCD control screen to offset the fine adjustment to reach perfect centre.

REPAIRING TORCH MIRRORS AND MOTORS

8. CHECKING THE FOCAL CLARITY:

1. Start the laser source, but DO NOT press the trigger
2. Face the torch towards a white surface 800mm away from the torch face.
3. Take note of the clarity of the red dot visible shining on the white surface.
4. Holding the torch 800mm away, the red dot should be perfectly round and have a distinct outside edge (Not hairy outline).

9. PRE-START CHECKS:

1. Power the laser ON, DO NOT press the torch trigger or enable cleaning button.
2. Take note if the laser beam is centred to the torch window
3. Check beam clarity again
4. Turn shielding gas / compressed air On, Test flow (small triggering).
5. Check your surroundings for the safety of other people
6. Fit your own Laser PPE.
7. If everything is perfect, Enable cleaning mode on control panel
8. Try multiple cleaning wave forms to ensure BOTH mirror motors are operating correctly
9. Short press the trigger to ensure the laser output and cleaning correctly
10. Observe LCD screen for any errors or alarms, especially Galvanometer and temperature alarms
11. The torch should be cold and not heating/warming up.
12. The torch should operate between 24 degrees up to 35 degrees operating range.
13. Should the torch temperature exceed 40 degrees Celcius, the machine will stop and show the alarm

10. TESTING & CLEANING:

1. Turn on the sheilding gas / compressed air.
2. Take note if the laser pilot beam is centred to the exact centre of the torch
3. Make sure the gas is set to the prefered pressure / flow.
4. Make the environment safe to use laser and alert people around you of the imminent danger of laser 
6. Run a test
7. Check for any potential torch defects or laser issues as mentioned in STEP 1 of this procedure.
8. The laser should be able to run for 5 minutes continuously without heating the torch handle. 

11. WATCH THE LASER CLEANER IN ACTION: