Laser cutting

 Hello all! I will be documenting what I have went through last Thursday, 27th October 2022. 

I had taken the laser cutter competency test and it was extremely fruitful because I managed to apply what I had learned merely through videos and a universal guide. 😁 To me, the test was easier than I had expected and it was really fun to cut out a small design on a 3mm plywood.

The test was held at Makerspace@Library and I had to use the Universal Laser Cutter. 

The software we had to use to upload our design is CorelDraw, but it can only be accessed in the computer next to the laser cutter as the license for this software is costly. 

How does the laser cutter work you ask? 🤔

Well, the laser cutter that is used in SP is the Carbon Dioxide(CO2) Laser cutter

Following the diagram above, the laser beam is created in the yellow tube that is filled with CO2. Next, with the help of mirrors and lenses, the laser beam is directed to the laser head and focused on the material surface. 

Electronically controlled motors move the laser head to cut or engrave the desired shape into the material of the workpiece.  The assist gas is from the compressor. Blowing compressed air at the area being laser cut helps prevent flare ups and keeps things clean by directing vaporized material downward and away from the cut, and away from the machine’s lenses and mirrors.

Of course there are certain hazards related to usage of a laser cutter, thus I will name 4 important hazards associated to the operation of laser cutting machine and their respective safety control below.

Hazards	Safety control measures	Pictures to support the explanation
1. Poisonous fumes are produced when cutting.	Fume extractor is connected to the laser cutter to remove these fumes.
2. Laser cutting acrylic and not removing the paper on the top side.	There is a poster behind the computer next to the laser cutter informing the user to remove the paper before cutting.
3. Possibility of the material igniting	There is a fire extinguisher next to the door of the laser cutting room.
4. Continuation of laser cutting after the cover is opened is dangerous if the laser is still active.	There is an engineering control coded into the laser cutter such that when the lid is opened, the laser cutting will continue, but there will not be any laser.

Based on hazard 1 and 3, the type of material to be cut also matters a lot and could determine the safety of our wellbeing. The list of materials that can be cut is the following:

Material	Photo of material
Paper/White card
Cardboard
Balsa wood
Acrylic
Plywood

There is also a list of materials that cannot be cut which are:

Material	Photo of material
PVC
Metal
Rubber

Next will be about the operating procedure of the Universal laser cutter.

Firstly, we have to switch one the power:

Steps and description	Photos to support the description
1.Turn on the switch for the Laser cutter, Air assist and the computer.
2.Turn on the switch for the fume extractor

Next, we have to import your .DXF file onto coreldraw and select the correct settings:

Steps and description	Photos to support the description
1. To import a .DXF file(after saving it on a thumb drive), select File>Import then select your file
2.Next, depending on what you want to do, you have to change the settings Vector Cut –  Pen outline Colour: RGB RED                         Line Width: Hair line   Engrave – Fill Colour: RGB GREEN                      Line Width: NONE   Vector Engrave – Fill Colour: NONE                                 Line Width: RGB GREEN	Click on the coloured box to change the settings. The crossed out box on the left is to change the fill. This would be the window to change the colour/line thickness

After importing and selecting the right settings, we have to send it to the laser cutter software with the correct material presets.

Steps and description	Photos to support the description
1. Once the material settings have been loaded, click on the Universal Control Panel (UCP) window in the taskbar.
2. 1.    Take note of what each button on the UCP represent. 1         Activate/ Deactivate the Laser cutter 2         Play Button to start Cut/ Engraving 3         Pause Button to pause/resume theCut/Engraving 4         Essential tools which will be covered next Settings – to change or set settings for different
3.Take note of the tools of the laser cutter: 1.       Zoom – You can also zoom in to the work file using your scroll mouse 2.       Focus – This tool will help you check with the help of a Laser dot. It is used to check if your work is within a workable space 3.       Move – You can use this tool to move your drawings within the available workspace. Note this is not a live view/action. 4.       Estimated time – This will help you determine the estimated time for you to cut/engrave your work.
3.After placing the material in the laser cutter, use the FOCUS tool to check whether your desired area of cutting is safe by cross checking the ruler on the software and the laser cutter.
4.Once it is safe, close the cover of the laser cutter and you can start cutting by click on the play button on the software or the laser cutter

Oh, and while the laser cutting is operating, there is a chance that a fire might start, so we need to know what to do when a fire has started.

DOs and DONTs	Photos to support the description
1.Any flame must die out within 1-2 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, remove material from the laser cutter  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.

Last but not least, my learning reflection from this test.

Well, to be honest, the competency test was quite intimidating before it was my turn. However, after taking the test, I realized that it is actually way more simpler than what I expected it to be. It is definitely fun learning how to use the laser cutter. While waiting for my turn outside of the laser cutter room, I had initially thought that we are supposed to vector cut the material first, then engrave it afterwards, but I realized that we can just do vector scoring(engraving) which does both at the same time. 

The process is very amusing to me because I get to see the laser cutting process with my own eyes and I really hope that I can use it again in the near future. One thing that I learned is that while laser cutting is more dangerous than 3D printing, the whole process feels faster and easier as compared to 3D printing. 

Oh, and if I am to design something, the dimensions on Fusion 360(designing software) has to be smaller than the actual dimensions that I want, because laser cutter is a form a subtractive manufacturing, so it takes away material from the main body. Also, before my test, Dr. Noel actually gave a really good tip to select the color and thickness of the design on CorelDraw, which is actually by highlighting the whole thing to RGB green first for engraving, then select the few parts and change it to RGB red for vector cutting. This tip actually made the process much faster. If not for this tip, I would have definitely selected each line and change the settings individually, which saves a lot of time.

 

Skill gained: Laser cutting!! 😆

That is all for this blog entry, see you soon!