blog entry #4

Week 10 

our first activity was to complete the laser cutting quiz in class and to do SOP once completed the quiz.. we were sharing answers to help one another to get 80% n above..

once quiz completed, we started our proper lesson about laser cutting.. there are two types of cutter made readily for us - epilog n universal 

we're taught on the components and the working principles of the laser cutter, it requires compressor and exhaust to work

we also have to understand the importance of choosing the correct materials for laser cutting as there are strengths and weaknesses for different type of laser cutter we are going to use.. one type of material we should NEVER use is any material containing chlorine because chlorine is highly reactive and corrosive, it will cause damage to the cutter 

some suitable materials are listed below vv

• wood 
• acrylic
• cardboard
• paper

these materials might cause burnt marks and small fire as we are dealing with laser... if small fire occur, we should attempt to extinguish it by blowing or removinng material from the laser cutter to prevent hazard. when cutting, we should never leave machine unattended even if it's for a short while !! we are also not allowed to stare into the beam while cutting, just a quick glance will do.. metal materials cannot be cut or engraved onto it

we also learnt how to use tools in CorelDraw such as 

1. rotation - manually rotates object via keyingin angles

2. round corners - round corners of objects with sharp corners with angle value

3. line weight - quickly adjust line weight to increase or decrease

4. selection tool - used to move object

5. jargon n tools

workflow of phone stand

i was inspired by a deep blue acrylic bookend i saw online. the clear, transparent material of the bookend made it look like a glass, and i loved the simple, geometric design as it will never go out of style !! i decided to use this design for my phone stand, with additional customisations to make it more unique, by adding a hook and instead of adding an image for engraving, i added my name to signify mine  :D

the dimensions of my iPhone 13 pro max is 16cm by 7.8cm by 0.76cm

Step 1: Create Sketch 

Step 2: Create Center Rectangle 

Step 3: Create Line (14mm long) and adjust the breadth (10mm)

Step 4: Create a 12mm long line

Step 5: Create a line (70mm) with a degree of 70°

Step 6: Create two lines

Step 7: Create a box and align it 

Step 8: Repeat for the bottom part

Step 9: Trim the unwanted lines 

Step 10: Repeat to get two of the same sketch

Step 11: Create a rectangle (56 by 20mm) 

Step 12: Create 2 rectangles (10 by 3mm) on the big rectangle

Step 13: Repeat steps 11 n 12

Step 14: Create a small rectangle (3 by 4mm) for hook

Step 15: Create horizontal rectangle (14 by 4mm) n vertical rectangle (4 by 10mm)

Step 16: Create a curve with Fit Point Spline and trim it

Step 17: Trim all the necessary lines

Step 18: Adjust all the parametric for kerf

changes made: 3mm to 2.6mm because kerf is 0.4mm

Step 19: Save as dxf

how i calculate kerf: 

Kerf is the width of cut made by the laser cutter. It is important to consider kerf when designing laser cut parts, especially when we are dealing with press-fits. Why is it important is because when we design a press-fit, it is important to allow for the kerf of the laser cutter. If the opening is not wide enough, the two pieces will not be able to fit together tightly. If the opening is too wide, the two pieces will be too loose and press-fit will not be secured. By taking kerf into account when designing press-fits, I can ensure that my phone stand parts can fit together tightly and securely.

First, I drew a 25mm by 25mm square on fusion360. Next, I exported the file into CorelDraw for laser cutting. Once the square has been laser cut out, I tapped the square on the machine before removing them to ensure all sides have been fully cut off. Next, I measured the length of the square with a vernier caliper and it shows me roughly about 24.6mm. I used the expected length minus the actual length which is 25mm – 24.6mm which gave me 0.4mm (kerf) and I use this to edit on the length from fusion360 before the cutting of my phone stand.

Kerf: Design width – actual width = 25mm – 24.6mm = 0.4mm

I did not manage to calculate the compensation as it is not necessary for my phone stand, so what I did is I use the dimensions of the hole (10mm length by 3mm width) which is 3mm width to minus away 0.4mm of kerf.

Design width: 3mm – 0.4mm = 2.6mm

On my sketch, I made modifications to the parameters that I had prepared initially. I adjusted accordingly and fusion360 will updates it automatically which is an advantage for me as it saves me much time because I do not need to adjust in manually. 

Workflow for preparing dxf file

Step 1: check compressed air. exhaust and air assist are turned on

Step 2: Click folder > Select file > click and drag

Step 3: Change orientation of shape to landscape

Step 4: Shift all the shapes to the top left side

Step 5: Change width to hairline

Step 6: Change colour of outline to (R:255 G:0 B:0)

Step 7: Change colour of name to (R:0 G:255 B:0)

Step 8: Click file > print > settings

Step 9: Click load > acrylic 3mm > open

Step 10: Print

Step 11: Switch on laser cutter

Step 12: Turn on machine

Step 13: Place the material (with paper) facing bottom 

Step 14: Close the cutter lid

Step 15: Press "Play" 

Step 16: Wait for process to finish

Step 17: Shut down compressor

Step 18: Turn off laser cutter and fume extractor

short video of laser cutter in action

short video of press-fit quality

final assembled product

my "hero shot"

Learning reflection: 

I have learnt so much from this laser cutting assessment from the difference type of laser cutter available in school, to the final production of my phone stand. I learnt about the basics of laser cutting and the different types of materials that can be used in the laser cutter and learned how to use CorelDraw to create laser cut files. I was also introduced to the concept of kerf, which is the width of the cut made by the laser cutter. This is important to consider when designing laser cut parts, especially when we are dealing with press-fits. I was able to successfully design, and laser cut a phone stand using the knowledge I learnt. I am proud of the final product, and I am confident that I can use these skills to create other laser cut projects in the future. One of the things I found most confusing about laser cutting was calculating kerf. However, I was able to overcome this challenge by following the examples given to us in the Brightspace, where they teach us how to find kerf before proceeding to cut. This allowed me to make the necessary adjustments to my design and I was able to laser cut the phone stand without problems arising. I realised the importance of making sure I calculate kerf before proceeding to laser cut my phone stand. Kerf is important to be considered when designing laser cut parts due to press fit. By taking kerf into account, I can ensure that my phone stand parts can fit together tightly and securely. I have also found perks being a pro user in fusion360. Initially when I started to create my sketch for my phone stand, I had to manually change the dimensions to create a perfect one. Now, I can make all my adjustments with the help of fusion360 parametric accurately and time efficiently. This will definitely help me with any upcoming laser cutting projects to save time and make it more precise. (~333 words)