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3. Computer Controlled Cutting

This week, I learned many things related to laser cutting, including how the machine works and how to determine the optimal speed and power settings for both cutting and engraving. I also learned about kerf—what it is and how to measure it. Additionally, I implemented a simple press-fit design using different types of joints: fillet, chamfer, and a standard joint. The fillet joint provided the best fit, as it was easy to insert into the comb. Moreover, I gained deeper insights into parametric design and how to create it using CAD software.

Hero Shot!

Group Assignment

You can find more details on our lab site: TechWorks - Computer Controlled Cutting

🔧 What I Did and Learned During this week, we explored computer-controlled cutting using the Trotec Speedy 400 laser cutter. Our lab instructor introduced us to laser cutter safety, including:

  • Wearing protective eyewear
  • Ensuring proper ventilation
  • Performing regular maintenance
  • Avoiding hazardous materials

✅ Material Testing

4mm MDF

  • Best cutting settings: 55% power, 0.27 speed
  • Best engraving settings: 40–80% power, 50 speed
  • Kerf measurement: 0.015mm

3mm Acrylic

  • Cutting required fine-tuning due to its reflective nature
  • Best settings: 40% power, 0.25 speed, 1000 Hz frequency

✅ Press-Fit Joint Testing

We designed a slot comb using parametric equations in SolidWorks, with slot widths ranging from 4.25mm to 3.75mm.
- The most secure press fit for 4mm MDF was at 3.95mm.

💡 What I Learned

  • How to safely operate a laser cutter
  • How to adjust settings for different materials and outcomes
  • How to measure kerf accurately
  • How to use parametric design to test tolerances and improve prototyping

Individual Assignment

Laser Cutting - Press Fit Kit

I designed multiple press-fit components using SolidWorks, focusing on simple yet engaging shapes suitable for children.

🧩 How to Make a Parametric Design in SolidWorks

Parametric design allows you to build models with dimensions and relationships (parameters) that can be easily modified later without redesigning everything from scratch.

✅ Step 1: Create a 2D Sketch

  1. Click on Sketch > select a plane (e.g., Top Plane).
  2. Click Sketch to begin drawing.
  3. Use sketch tools like Rectangle, Circle, Line, etc., to create your design.

✅ Step 2: Add Dimensions (Very Important for Parametrics)

  1. Go to the Smart Dimension tool.
  2. Click on each element (line, circle, etc.) to define its size.
  3. Enter dimension values — these will be your parameters.


✅ Step 3: Use Global Variables (For Flexible Parametric Control)

  1. Click Tools > Equations.
  2. In the Equations dialog:
  3. Click on Add Global Variable.
  4. Give it a name, such as thickness = 4mm.


  1. Go back to your sketch.
  2. Click on a dimension > right-click > Link Value.
  3. Choose your global variable (thickness).



Repeat this process for all dimensions you want to be linked.

Now, any change to one linked dimension will automatically update the others.

✅ Step 4: Test the Parametric Design

  1. Double-click on any linked dimension.
  2. Change its value (I subtracted 0.1 mm as a tolerance).
  3. Hit Enter — all linked dimensions will update accordingly.

Parametric models are perfect for laser cutting, 3D printing, and Fab Academy work!

🔄 Exporting and Preparing for Laser Cutting

After finalizing the parametric designs in SolidWorks, I exported the sketches as DXF files. I then imported these files into Inkscape, where I adjusted the necessary settings to prepare them for laser cutting. This included configuring key parameters such as power and speed to ensure accurate cuts that matched the design specifications.

The settings I used for the cut and engrave.



These components can be assembled into various structures, such as:

Car

Giraffe

Table and Multi-Layered Table

Space Orbit Model

Drone

These designs demonstrate how parametric modeling and laser cutting can be combined to create customizable, interactive kits for education and prototyping.

I used the Roland GS-24 machine to make a laptop sticker. I explored how it cuts materials — it’s a very simple machine. I decided to cut the Fab Academy logo to put on my laptop, so I opened the logo in Inkscape. Then, I printed it using Roland CutStudio and ensured that the dimensions of the printed object matched the design.

The steps below describe the process:

1️⃣ Open the logo in Inkscape
2️⃣ Path > Trace Bitmap

Step 1
Step 2
Step 3

3️⃣ Make the stroke style ‘hairline’, and make sure that the stroke is not filled — just an outline colored red.
4️⃣ Open the design in CutStudio

CutStudio 1
CutStudio 2
CutStudio 3
CutStudio 4

5️⃣ Insert the roll in the correct place

Insert Roll 1
Insert Roll 2

Don’t forget to lock it down using the lever on the machine. Lever

Machine Closeup 1
Machine Closeup 2

6️⃣ Check the speed of the machine
Speed Check

7️⃣ Then press Ctrl + Print
Print

I made the logo with three different colors, and I used tape for the removal and placement process.

Color 1
Color 2
Color 3
Final Sticker

Isn’t it nice? 🤩

Challenges and Troubleshooting

During laser cutting, we encountered an issue where the nozzle and lens were misaligned, causing the machine to fail in cutting objects properly.

Steps Taken to Fix the Issue:

  1. We carefully realigned the nozzle and lens to ensure the laser beam was correctly focused.
  2. We checked and cleaned all mirrors to remove dust and residue that might affect the laser’s intensity.
  3. After these adjustments, the machine performed as expected, producing clean and precise cuts.

This troubleshooting experience highlighted the importance of regular maintenance in ensuring the laser cutter operates efficiently.

Files