LASER CUTTING

Laser Cutting

Halo! Welcome back to another blog! This week I have learnt another interesting topic.... LASER CUTTING. This honestly sounds very futuristic, and I was so excited to learn!

How does it work?

The CO2 Tube, is a glass tube with gas sealed within, namely carbon dioxide and some nitrogen. High voltage electricity is pass through the tube which produces an invisible high power beam. 

The laser exits the end of the tube, and is immediately bounced on the first mirror, then down to the second mirror and over to the third mirror, through the head and through a focusing lens which is inside the carriage and onto the workpiece.

The combination of forward, back and side to side movement allow the laser to get bounced around in any direction, allowing the laser cutter to cut and engrave any shape.

IMPORTANT: Before using Laser Cutter, remember to on the air compressor and the Exhaust. Air Assist is used to blow the cut off debriefs away so that small or no fire will be produced. Exhaust must be on so that toxic gases can be sucked in. Only open the lid of the laser cutter 1min after material has been cut or engraved. This allows time for the Exhaust to suck in all the toxic gases.

Figure 1: Detailed View on Laser Cutter

What are the suitable materials?

• Wood (up to 6mm) *burnt marks and fire may occur*
• Plywood
• Natural Wood
• MDF

• Acrylic (up to 5mm)

• Cardboard *burnt marks and fire may occur*

• Paper *burnt marks and fire may occur*

Safety

1. Do not stare into the beam as it is not goof for our eyes.
2. Do not use materials that contains chlorine of foam.
3. Do not cut or engrave Metal materials.
4. Do not leave machine unattended while cutting or engraving. This is to prevent accident from happening such as fire.
5. If a small fire occur, extinguish it by blowing it away, or remove the material from the laser cutter.
6. If material cannot be cut through after 2 attempts, check is the focus lens is dirty. Continue use of dirty focus lens will lead to a cracked focus lens.

Vector vs Raster

	Vector	Raster
Resolution	Scalable Image remains sharp even if it is zoomed in or out.	Pixel Image is slightly blur-ish when zoomed in but is sharp when is zoomed out.
File Size	Small. File size stays the same even if image is enlarged.	Large. If image is enlarged, file size increases.
File Format	EPS, SVG, AI	BMP, GIF, JPG, PNG, TIFF
Made of…	Made of Anchor Points which are defined by coordinates and Mathematical formulas. Through path, these Anchor Points can be connected.	Made of millions of coloured picture points, aka Pixels.
Application	Used for less detailed images.	Is almost used for everything but is best used for detailed images.
	Both Vector and Raster graphics can be converted into the other file.

Kerf

Kerf refers to the amount of material that is removed by the cutting tools. To have a tighter connection between 2 joinery, material that is going to be laser cut can have dimension of 0.01cm smaller.

Practical (11/11/21)

Improved SOP (Epilog Fusion Pro Machine):

Start Up: 

Step 1: Open the cover of the Laser Cutter fully.

Step 2: Clean the lens of the Laser Cutter.

Step 3: Turn on the Fume Extractor (Click on the green switch)

Step 4: Turn on the main laser cutter (Click on the black switch)

*Do not need to turn on Air Compressor as it is already built inside the Laser Cutter*

Operation:

Step 1: Measure the thickness of material used:

Step 2: Open CorelDraw on the computer

Step 3: File, open new

Step 4: Import your .DXF drawing

Step 5: Set line weight, color and fill

	Color	Line Weight	Fill
Vector Cut	Red R: 255 G: 0 B: 0	Hairline	-
Engrave	Green  R: 0 G: 255 B: 0	-	Apply Fill

Step 6: 4th icon from the top right, click on print

Step 7: Gently open the cover of the Laser Cutter fully

Step 8: Place material in the Laser Cutter

Step 9: Gently close the cover of the Laser Cutter

Step 10: Adjust/ Position the area of laser cutting using the built-in camera in the Laser Cutter. Simply drag the cutout to the space where we want to cut on the material. It is always best to save materials

Step 11: Load material library and choose the correct material, and thickness

Step 12: Select auto focus: thickness

Step 13: Click on print

Step 14: Go to the Laser Cutter navigation, select our file and then press print

Step 15: Wait for at least 1 min after our product has been laser cut

Shutdown:

Step 1: Open the lid fully and remove the finished laser cut product from the honeycomb bed

Step 2: Remove and dispose all the waste material

Step 3: Close the lid of the Laser Cutter gently

Step 4: Shutdown the Laser Cutter

Step 5: Turn off the fume extractor

Step 6: Shutdown the PC

Description

The main changes were in the operation part of the laser cutter. Most steps were removed from the original SOP as the Epilog Fusion Pro machine is more advanced as compared to the Epilog Fusion M2 Machine. 

In my original SOP operation, we did not specify on the color chosen. (Eg. color red, R:255 G:0 B:0) Without specifying on the colour chose, the Laser Cutter machine will not understand what the colour indicates and thus cannot perform the desired activity. 

Figure 2: Epilog Fusion Pro Laser Cutter

Figure 3: Inside of the Laser Cutter

Figure 4: Camera built into the Laser Cutter for easier positioning of material

Figure 5: Interface on Laser Cutter Machine

Figure 6: Positioning of Product on material

Figure 7: Cut-out of our Laptop Stand

Figure 8: Built Laptop Stand

Figure 9: Laptop Stand with Keyboard

Figure 10: Laptop stand with Laptop and Keyboard

Reflection

This week, my team were tasked to design something with the use of Parametric design. We had came up with the idea of making a Laptop stand. It was generally an easy task as we were all able to design our design on Fusion-360 successfully. 

However, we had faced a problem. We had forgotten that the thickness of material was only a maximum of 5mm, which is a problem for our laptop stand as the hole where our base of the laptop stand and the stand of the laptop stand intersects were not deep enough. Thus, we needed to change our design so that the stand is able to go through the hole, and is then able to securely hold the weight of the Laptop. We had changed our idea of only engraving a certain amount  into the base to having a hole in the board. 

Laser cutting can and will be a very important and helpful tool. With whatever design we have using our imagination, as long as we know how to create it with the help of Fusion360, we are able to laser cut anything we want. Laser cutting is a manufacturing process which can eliminate the need for machining on many engineering jobs, enabling us to save money on manufacturing costs. Laser cutting technology also enables us to cut complex shapes without the need for tooling and at a similar or faster speed than other cutting methods

Citations:

• 2019. How CO2 Laser Cutters work and ...Why you might want to build one!. [image] Available at: <https://www.youtube.com/watch?v=t4BfQGhhbOQ> [Accessed 25 October 2021].
• 2017. Vector vs Raster Graphics | Buddy Media. [video] Available at: <https://www.youtube.com/watch?v=p2thSkOa_Xg> [Accessed 25 October 2021].
• 2020. A Quick Look at Kerf. [video] Available at: <https://www.youtube.com/watch?v=jDylvHraCAU> [Accessed 25 October 2021].