Laser Cutting

For the first practical session of our journey in CPDD, we can indulge in our first taste of LASER CUTTING!!!

There are 3 different Laser Cutters available to us in the Fablab:

However, the one that we will be mainly using is the Universal Laser cutter.

Firstly, how does the Laser Cutter work?

• A laser cutter works by having electricity run through a carbon dioxide tube, the electricity excites the gas molecules and creates a beam of high-powered infrared light.

• The laser is then bounced from mirror to mirror where it is finally passed onto the lens where it is exposed to the workpiece.

• The air assist is present to help prevent flare-ups and ensure cleanliness by directing vapourised material downwards away from the cut and away from the machine's lenses and mirrors.

What's the difference between Vector and Raster?

• Vector is rendered by a computer using an analytical mathematical formula. Resulting in its accuracy and sharpness.

• Raster images are made up of tiny colored pixels resulting in it being less accurate and more suitable for detailed images.

1. These are the 4 important hazards and the respective safety control measures on the operation of laser cutting machine:

​Hazards	Safety Control Measures	Pictures to support the explanation
​Accumulated Fumes and gases can pose as a fire hazard	​Installation of the fume extractor to remove unwanted gases and fumes
Material can catch fire throughout the laser cutting process	​Fire extinguisher is used in the event that the fire goes out of control
​Radiation exposure from the laser onto the user	​Laser interlocks prevent the radiation from hurting the user by trapping the laser in the cutter
Leftover debris can act as a fire hazard	​Air assist is installed and used to remove debris from around the contact point

Aside from hazards, we should also know what materials can or cannot be cut or engraved using a laser cutter machine in the Fablab.

2. Below are the materials that can be cut/engraved using a laser cutting machine in FabLab.

​1	Paper/White card
​2	Cardboard
3	Balsa wood
4	Acrylic
5	Plywood

Below are the materials that can’t be cut/engraved using a laser cutting machine in Fablab.

1	Metal
2	PVC
3	Foam
4	Rubber

The allowed thickness for all materials to be cut is 5mm maximum.

Next up are the steps to operate the Universal Laser Cutter.

3. Below are the steps for the operation of the UNIVERSAL laser cutter machine in FabLab:

a. Starting the compressor, turning on the laser cutting machine and fume extractor.

1.	​Switch on the POWER for the laser cutter, AIR ASIST and EXTRACTOR
2.	Switch on the FUME EXTRACTOR

b. Importing a .DXF file to coreldraw and modify the lines/fill for cutting and engraving.

1.	Click on File>Import>Select your .DXF File and press Import
2.	​Click on Tool on the bottom right of the screen
3.	Click on the Colour drop-down menu and change to RGB
4.	Change the values accordingly to the laser wanted
5.	Click on Width drop-down menu and change to Hairline(for vector and vector engrave) or None (for engrave)
​6.	​Click on Fill tool on the bottom right of the screen
7.	Click on Colour model and change to RBG
8.	Select the colour wanted and click OK

c. Sending the CorelDrawlaser-cutting drawing to laser cutter software and setting the laser cutter power, speed, PPI in the software.

1.	​Click on File>Print
2.	Click on Gear next to the printer
3.	Click on Load
4.	Select the PROFILE that matches your material type and thickness then click on Open
5.	Click on Apply>OK>Print

d. Starting the job on the laser cutter machine.

1	​Click on Task tray(at the bottom right of the screen) and select universal control panel (UCP)
2	​Activate the laser cutter in UCP (red button
3	​Shut the lid gently
4	Press either play button in the UCP or the physical button(green button) on the laser cutter

Shut down Procedure

1	Ensure the lid is remained closed for 1 min to allow for smoke and fumes to be exhausted
2	Deactivate the laser cutter and off the switch for the laser cutter, exhaust and air assist
3	​Discard unwanted materials(big item goes to the recycling bin and small item goes to the bin)

e. DOs and DONTs when there’s flame/fire on the material being cut.

	DOs	Photos to support the description
1	Immediately hit the emergency button/switch off the power
2	Open up the cover to cut off the laser
3	Attempt to blow off the flame
4	​If the fire is uncontrollable, use fire extinguisher

	DONT's	Photos to support the description
1	​Do not use the fire extinguisher when the fire is small

4. Below is my Learning Reflection on the laser cutter activities.

All in all, I found the Laser cutting activities to be very important as this is a core skill for us as Chemical engineers. I had spent ample time thoroughly preparing myself by going over the videos and online resources provided by Dr noel. I feel that I am competent enough to use the Laser cutter without any major obstacles like a big fire.

The competency test was relatively straightforward forward however the atmosphere in the waiting room was still incredibly tense. I was afraid that I would fail the competency test and would have to take it another day. I was not entirely sure about the step-by-step procedure of the laser cutting especially the focus and relocation portion as I was not entirely confident in my ability to use Coreldraw.

Throughout the competency test, I became more confident in the procedure to operate the laser cutter but I soon became nervous as the lecturer facilitating the test was very stoic. Whilst proceeding with the competency test, I made 2 major mistakes. One was forgetting to select the material settings eg. 3mm Acrylic etc, and another was not knowing how to utilize the focus and relocate. At the end of the competency test, I found that my SOP was severely lacking and lacked the content needed for me to rely on it fully. There were a few instances where I lost focus and needed to rely on my SOP however, It was too wordy and lacked the thorough steps to help me through. The lecturer that facilitated my competency test also commented that my SOP needs some work. On the bright side, I found where my incompetencies lie and I can hope to improve them in the near future.

Sidenote, I personally thought that the Laser cutting process would have taken a long time but It only took 5 to 10 seconds to fully cut. All in all, this practical session was very productive and vital to our future in this module and course. I'm glad to have been able to pass the competency test but It was also an eye-opener to what I have to improve on