Blog 1 (Laser Cutting)

Hello everyone! In my first blog of CP5070, I will be sharing with you my first ever experience operating the laser cutter. Before operating the laser cutter, there was so much information that was needed to be known by us. It was quite overwhelming but I spent a few days digesting the information and formulate a Standard Operating Procedure (SOP) to assist me during the operation of the laser cutter.

In this blog, I will be describing the following:

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:

   1. Starting the compressor, turning on the laser cutter machine and fume extractor.

   2. Importing a .DXF file to Corel-draw and modify the lines/fill for cutting and engraving.

   3. Sending the Corel-draw drawing to laser cutter software and setting the laser cutter power, speed, PPI in the software.

   4. Starting the job on the laser cutter machine.

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

4. My Learning reflection on the laser cutter activities.

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
The material catches on fire during cutting.	Engineering Control - Air assist installed at the nozzle helps to blow away debris around laser head to minimise chances of the material catching on fire. Administrative Control - Safety briefing was conducted to ensure that students know the location of the emergency exit and the fire extinguisher. In addition, students are taught on how to use a fire extinguisher in case of an emergency.
2. Staring at the laser during cutting which would result in permanent damage to the eye.	Engineering Control - Close the lid before cutting to reduce the glare of the laser beam. Administrative Control - Students are instructed not to look at the laser beam during the cutting process.
​3. Dense smoke produced during cutting which may cause breathing problems.	Engineering Control - Fume extractor must be on during the cutting process so that the smoke particles produced can be contained.
4. Using material that contains chlorine such as polyvinyl chloride (PVC).	Administrative Control - Students are instructed not to use PVC. Instructors would inspect the material used before cutting can be done.

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

Material	Photo of material
Acrylic
2. Plywood
3. Cardboard

Below are the materials that can't be cut/engraved using laser cutting machine in FabLab.

​Material	Photo of material
Metal
2. Foam
3. Rubber

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

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

​Steps and description	Photos to support the description
Switch on the power for the air compressor, fume extractor and laser cutter machine.
2. Switch on the power for the light switch.

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

Steps and description	Photos to support the description
Import a Fusion file to Corel Draw (Select File > Import > Select your .DXF file and press import.)
​2. Depending on the user's desire to vector cut, engrave or vector engrave, the following steps are to be followed. Vector Cut - Pen Outline Colour: RGB Red Line Width: Hairline Engrave - Fill Colour: RGB Green Line Width: None Vector Engrave - Pen Outline Colour: RGB Green Line Width: Hairline RED - (R:255 G:0 B:0) GREEN - (R:0 G:255 B:0)

c. Sending the Corel Draw drawing to laser cutter software and setting the laser cutter power, speed, PPI in the software.

Steps and description	Photos to support the description
After modifying the lines in Corel Draw, it is ready to be sent for laser cut. Click on File > Print.
2. Click on the cogwheel.
3. Universal's Material setting will appear. Click on LOAD for more material settings.
4. Select the presets that match your material type and thickness and select OPEN.
5. Some laser settings that are important for the user to know. Power - The power output of the laser. (Usually do not go beyond 50%) Speed - The movement of the laser head. (Usually, it is set to low speed) PPI - Pulses Per Inch is a way to control how many times the laser pulses over a given distance during the cutting process. (Usually, it is set to high frequency) Z-axis - Usually set as the material height for the optimal focus point Once done, click OK and subsequently click Print.

d. Starting the job on the laser cutter machine.

Steps and description	Photos to support the description
1. Click on Universal Control Panel (UCP) icon shown on the taskbar.
2. Understanding the Universal Control Panel (UCP) Power Button to activate/deactivate the laser cutter Play Button to start cut/engrave Pause Button to pause or resume the cut/engrave Essential Tools Under Essential Tools, there are 4 tools to be familiar with. Zoom - Zoom in using the scroll wheel Focus - Check if your work is within the workable space using a laser dot Move - Move drawings within the workable space Estimated time - Determine the estimated time to finish your cut/engrave
3. Click the Power Button to activate the laser cutter. If the Play Button is green before the UCP has been activated, deactivate and activate it again.
4. Place the material at the top left corner of the laser cutter. As shown from the image, the top left corner of the laser cutter is in zone 1.
5. Use the move tool and move the object to the empty space of the material. (Try to move the object to the very edge of the material. Allowing 0.50 mm clearance from the edge.)
6. With the lid open, click on the focus tool, and a crosshair will appear.
7. Using the focus tool, check all the corners of the object to ensure that it is within the safe cut zone on the material.
8. Click on the Estimated Time Button and press the Start Button to check for the timing.
9. Shut the lid and press the Play Button on the UCP or the Physical Button on the laser cutter.
10. Once the cutting is done, wait around 1 minute to let the extractor remove the toxic particles.
11. Gently open the lid and tap on the cut material to see if it is free from the main material. (If it did not cut through, inform the staff-in charge as the lens might be dirty.)
12. Steps to take when shutting down. 1. Remove any unwanted materials 2. Deactivate the laser cutter. 3. Switch off the necessary switches. 4. You need not shut down the PC.

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

DOs and DONTs	Photos to support the description
DOs 1. Any flame MUST DIE OUT within1-2 seconds. If the flame persists, lift the lid of the laser cutter and stop the cutting operation. 2. If the fire is negligible, try putting it out by blowing it off. 3. If the fire is unable to blow off, a. remove material from the laser cutter. b. place it on the floor and step on it to put out the fire. 4. If the fire is uncontrollable, go to the closest fire extinguisher and put it out. Get people’s attention by shouting for help.
DONTs 1. Leave the scene immediately without informing anyone.

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

It was an enjoyable experience to learn about a CO2 laser cutter and to physically operate one too. I will be reflecting back on my journey in the past two weeks.

In the first week, the class had a lesson on laser cutters, specifically a CO2 laser cutter. I learnt that CO2 laser cutters are one of the most common types of laser cutters. As its name suggest, it uses carbon dioxide which is filled inside of a glass tube where high voltage electricity is passed through the tube which excites the gas particles and produces an invisible beam of high-power infrared light, otherwise known as a laser beam. The laser beam will then bounce from three separate mirrors and finally through the focus lens, and into the workpiece. The focus lens' main purpose is to converge the laser beam into a single spot to generate enough power to cut the material. Most importantly, something called "air assist" is vital to be at the nozzle to blow away the debris during the cutting process to reduce the chances of the material burning. It was really interesting learning about the working principle of the laser cutter. During secondary school days, I had learned the concept of convex lens. Some examples of convex lens I knew was magnifying glass and the camera lens. It was fascinating to find out that a laser cutter used the same kind of lens to function.

After learning about the way laser cutters work, I learnt about the hazards and safety associated with it too. Some of the main hazards include fire on the material, staring into the beam and using PVC material. We must know their respective safety control measure in case of an emergency. Following on, I learnt about the suitable materials that can be used in the FabLab. They were acrylic, plywood, cardboard and paper. We were not allowed to cut metal since they are relatively dangerous to cut and the laser cutters in the FabLab are suited to do the job.

We also learnt about the differences between vector and raster. Vector graphics are digital art that are rendered by a computer using a mathematical formula. They consists of anchored dots and connected lines and curves. On the other hand, raster graphics are made of tiny pixels and are usually created by digital cameras.

Moving on, I learnt about a software that will compliment the laser cutting process. Its called "Corel Draw" where we would import our fusion files into the software. From there, depending on whether we want to vector cut, vector engrave (scoring) or engrave, we have to input their designated colour. There are other additional tools in Corel Draw to assist in designing our product.

The last thing we learnt was something called "kerf". It is essentially material that is burned away during the cutting process. Its an unintentional process which would ruin the quality of your end product. For example, if I wanted to design a simple container with a snugly fit lid and I decide to program the laser cutter according to my design. The end result would be a failure as the lid would be loose on the container due to kerf. To counteract this phenomenon, design the product in a way to allow about 0.50 mm leeway. However, the amount of leeway to give greatly depends on the material type you are using so extensive research is required before doing laser cutting.

At the end of the lesson, we were required to complete a laser cutting quiz to ensure that we are well informed of things required before we head for the competency test in the following week. I certainly did not perform well as I took 11 attempts to achieve full marks on the quiz. There was a learning package that we were suppose to look at before taking the quiz. However, I refused to do it, assuming I had enough knowledge to ace the quiz. Due to my ignorance, I had wasted a lot of time and also making me very frustrated. Before week 2, the class had to produce a Standard Operating Procedure (SOP) that would help us during the competency test.

During the competency test, I did not have the need to refer to my SOP since I knew the steps like the back of my hand. The only slight confusion I had during the test was the selecting design itself to colour code it for the cut in Corel Draw. The design was basically a square shape with the text "DCHE" on it. I thought I had to colour the outline of the square and the text separately. Thus, I was trying to outline the square first, however, I seem to only be able to select both of them at once. So I went with the flow and colour both of them first and subsequently was able to colour the text. This small incident was something I was expecting as since it was my first time using the software and I only have information just by looking through the slides given by the lecturer. I guess it tests your quick thinking and judgement when navigating a new software with limited help. However, I would have prefer to have physical experience with the laser cutter before the competency test. In the end, I passed and will be looking forward to future laser cutting sessions.