Hello everyone!
In this page, I will describe:
1. The 4 important hazards associated to the operation of laser cutting machine and their respective safety control measures (administrative/engineering control).
2. The materials that can be cut and can’t be cut using laser cutting machine.
3. The steps including pictures on the operation of UNIVERSAL laser cutter, that consist of:
a. Starting the compressor, turning on the laser cutter machine and fume extractor.
b. Importing a .DXF file to coreldraw and modify the lines/fill for cutting and engraving.
c. Sending the coreldraw drawing to laser cutter software and setting the laser cutter power, speed, PPI in the software.
d. Starting the job on the laser cutter machine.
e. DOs and DONTs when there’s flame/fire on the material being cut.
4. My Learning reflection on the laser cutter activities.
Firstly, the 4 hazards that comes with using the laser cutter.
First hazard: Staring at the laser beam for long periods of time.
This is because the laser that is produced by the machine is as bright as the sun! Therefore it is important to ONLY take glances at the beam to ensure that the laser cutter is working. As seen below the beam is really bright.
Administrative control: users are reminded not to stare at the beam as it will damage their eyes.
Second hazard: Materials may catch on fire.
Since we are using a laser, it will produce a lot of heat in order to cut through the material, hence it may lead to the material catching fire🔥🔥.
Administrative control: Users are briefed on what to do when the material is caught on fire and how to put it out. Users are also told where the fire extinguisher is at. As seen below, there is a fire extinguisher near the entrance of T1442 (FabLab).
Third hazard: Using a dirty lens.
When using a dirty lens, it will result in the material not being able to be cut through cleanly. In this case, the lens may also break, and breaking a lens will cost as much as $5000 which is a lot of damage to one's pocket.
Administrative control: Users are told to do another test cut to make sure that the fault indeed is the lens being dirty. Users should then seek help from the Technical Executives (TEs) for help.
Fourth hazard: Soot particles
Since the laser is essentially burning the materials, soot will be formed. When there is an excessive amount of soot, it will catch on fire and the soot particles may end up on the lens which brings us to the third hazard mentioned above.
Engineering control: There are exhausts built into the laser cutter which would help create negative pressure so that the particles can flow out of the working area of the laser cutter. The soot particles would then get trapped in a series of filters in the exhaust.
Administrative control: Users are briefed to turn on the exhaust and air assist (if available).
Next, I will be sharing the materials that CAN and CANNOT be cut/engraved using the laser cutters in the FabLab
Materials that CAN be cut/engraved are:
Wood (up to 6mm):
Plywood
Natural Wood
Medium Density Fibreboard (Need to check with TEs before carrying out the job)
Acrylics (up to 5mm)
Cardboard
Paper:
Art paper & Technical board
Materials that CANNOT be used:
Metals:
Rubber:
Anything that contains Chlorine/Foam:
PVC
Foam board
Now, I will be sharing the steps on how to operate the UNIVERSAL laser cutter machine in the FabLab:
1. 1. Switch on the power for the laser cutter, air
assist, and extractor (Shown in the red box)
2. Light switch as well
b. Importing a .DXF file to coreldraw and modify the lines/fill for cutting and engraving.
1. Select
File > Import> Select the .DXF file and click import
2. When the shape is in coreldraw, select the shape and a menu will appear on the right-hand side.
Click on the object and delete one of the layers named "curve" as it makes the drawing have a thicker border.
Next, click the object and change the lines of the object according to what you want.
|
Vector Cut
|
Engrave
|
Vector Engrave
|
|
Pen outline: RBG Red (Red 255)
Width:
Hairline
|
Fill colour: RGB Green (Green 255)
Line Width:
None
|
Fill colour:
None
Line Width:
RGB Green (Green 255)
|
c. Sending the coreldraw drawing to laser cutter software and setting the laser cutter power, speed, PPI in the software.
Sending the file to print:
1.
1. Select File> Print
A menu with a cogwheel will pop up, click on the cogwheel
3.
1.
Universal’s Material setting will appear
1.
4. Click on LOAD for material settings
2.
5. Select the pre-set that matches the material thickness and type and select OPEN
6. After you are done with selecting the material, click on Print to get the file to the UNIVERSAL CONTROL PANEL.
Details to take note of
1.
Power
-
Output power of the laser. 100% is maximum. If
power is too high, will cause ugly charring. Dark wood or stamp engraving needs
a higher power compared to paper.
2.
Speed
-
Movement of the laser head. Higher speed = short
exposure time. (Vice versa)
3.
PPI
-
Pulse Per Inch, (PPI), is a way to control the
number of times the laser pulses over a given distance during the cutting
process. The higher PPI, the smoother the cut, however this causes more heat
which results in charring or melting.
4.
Z-Axis
-
Usually set as the material height for optimal
focus point
Once done click “OK”
d. Starting the job on the laser cutter machine.
1.
1. With the lid open, use the focus tool and a crosshair will appear.
2. Check if the file is within a safe area of the material where it fits. To do this, Click as close as possible to the bottom
right corner of the file, Click as close as possible to the top
left corner of the file
3. After
checking if the file fits, click on the “Estimate Job Completion Time”
And “Start”
4. When everything is in place, shut the lid gently.
5. Either press play on the physical button or on the Control Panel.
6. After finishing the print, DO NOT LIFT
the lid immediately, let the toxic smell and particles be removed by the extractor.
(Wait for about 1 minute)
7. Once extraction is complete, Gently lift
the lid and tap on the material to see if it has been properly cut through. If
never cut through, inform staff.
8. After removal, do the following:
-
Remove any unwanted materials and dispose
of them,
-
Deactivate the laser cutter,
-
Switch off necessary switches,
You DON’T need to shut down the PC
e. DOs and DONTs when there’s flame/fire on the material being cut.
DOs:
-Do not panic, if it is a small flame, try to extinguish it by blowing it out.
-If the fire persists for more than 1-2 seconds, stop the print and put the material on the floor, and step on it to put the fire out.
-If the fire is too big, shout for help and use the fire extinguisher to put it out.
DONTs:
- Do not continue your print.
- Do not leave print unattended.
- Do not run away without telling the TEs.
4. My Learning reflection on the laser cutter activities.
It was a very new experience for me to do anything related to laser cutting. I really enjoyed how the competency test really relied on how much we retained from the videos, SOP that we made as well as the crash course that Mr Louis gave us. During the competency test, I did blank out during 1-2 steps and Mr Louis was nice enough to allow me to recall and carry out the step that I missed without telling me the answer. At the end, he gave feedback on what I should have done instead. I found this way of self-learning a more efficient one as it really depends on how much I understood and absorbed during my own time instead of information being force-fed to us.
Creating our own SOP was also a fun activity to do as I was not really bound to a certain format and I could include anything I wanted which was not stated in the guidelines. It was interesting looking at my peers' SOP compared to mine as we were only allowed 3 pages. This means that everyone was creative with how they formatted their SOP.
All-in-all, I think that laser cutting is a useful skill to have as it would allow for me to create clean and precise cuts or engravings if needed in the future.
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