Identifiers
Date/Time: 4/1/18 11pm
Equipment: Thunderlaser laser cutter
Collaborators:
- Jake Lee (maintenance, writeup)
- Thomas Orr (consultation)
Images Album: https://imgur.com/a/VvAG3
Relevant Terms
- The air assist cone is the blue cone from which "the laser comes out"
- The elbow joint connects the blue air hose into the air asssist cone
- The head mirror redirects the incoming laser downwards onto the material on the bed
Symptoms
- When cutting a thick piece of wood, a large flame consistently flared up from the material up onto the head. This flame was clearly abnormally large.
Diagnosis
- The compressor was not plugged in - it was previously unplugged due to the sound during filming (the laser cutter had to look like it was on)
- Note: always place a large sign or indicating a major equipment change or modification.
- As soon as the compressor was plugged in again, the flame completely subsided, but left significant damage.
- The elbow joint, made of plastic, was burnt and boiled. A significant leak can be seen. See Figure 1 and Figure 3
- The aluminum nozzle was covered with a layer of soot.
- The head mirror had significant soot residue. Note that this may be due to regular usage. See Figure 4
Solution
- Elbow joint
- We had a spare elbow joint of the same specifications from a previous nozzle that was damaged. See Figure 2
- The air hose detaches by pushing down on the white ring and pulling up on the air hose. Much like a bowden tube on the ultimaker 3D printer.
- The joint can be removed from the cone by using a wrench on the hex nut.
- Replace the joint.
- Soot buildup
- While cleaning this is not critical to operation, consider it preventative maintenance.
- To remove soot buildup:
- Wipe off the parts with paper towel to remove the uppermost layer. This should be good enough for indirectly affected parts.
- The air assist cone can be screwed off of the head.
- Use paper towel with 99% IPA to remove more soot.
- Some particularly difficult soot can be removed with a light abraisive, such as fine-grain sandpaper or fine steel wool. I used steel wool myself and it worked very well.
- Replace the air assist cone.
- Head mirror
- Unscrew the three silver spring-loaded screws, taking care not to turn the brass alignment screws. Some tape would work.
- Saturate the mirror with optical cleaning solution, or 99% IPA.
- Dry the lens with a microfiber cloth, using a second one to completely dry if necessary. See Figure 5 for the result.
- Replace the mirror.
- If the brass alignment screws were changed, realigning the mirror can take time and finesse. Take time to adjust the alignment knobs back and forth to find alignment.
Figures
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
