Week 3: Computer-Controlled Cutting: Laser Cutting

💡 Note: You can find the project files here

1. Idea

For this week, I wanted to create an assignment I would be proud of, so I decided to make a car using 3 mm MDF.
car

2. Design

  • Select a reference image
    • I did not have a clear idea of the car's dimensions, so I selected this photo from the internet as a reference.
    car
  • Generate a 3D model
    • The 2D reference image was not enough to determine the exact dimensions, so I decided to create a 3D model based on it. I used Meshy AI, which offered free downloads of 3D models generated by the Meshy 4 AI model for a limited time, and that was enough for me.
    car
    Here is the 3D model generated by Meshy AI.

    Meshy_AI_ Gray_ Pickup_ Truck_generate by malak-alsharqawi on Sketchfab

  • Prepare parameters
    • Before drawing the 3D model, I had to prepare parameters to make my design parametric. Here is how to define and use parameters in Fusion 360.
    • Go to the "Modify" menu and select "Change Parameters".
      • parameters
    • In the Parameters dialog box, click on the "+" button to create a new parameter.
      • new parameter
    • Give your parameter a name (e.g., "SlotWidth") and set its value (e.g., 3 mm).
      • define parameter
    • Click "OK" to save the parameter.
    • Now, to use the parameter in your design, simply type the parameter name (e.g., "SlotWidth") in any dimension field instead of a specific value. This way, if you need to change the slot width later, you can just update the parameter value, and all dimensions that use that parameter will automatically update accordingly.
      • use parameter
  • Drawing the 3D model
    • I used Fusion 360 to draw the 3D model and generate the 2D drawings for each part of the car.
    Here is the 3D model from Fusion 360.

    Car_fusion360 by malak-alsharqawi on Sketchfab

3. Prepare model for cutting

I had to convert my model from 3D to 2D for the cutting process, so I projected the 3D model onto 2D planes to create the necessary cutting paths. Then, I put the 2D projections into one file to prepare for cutting.
💡 Note: At first, I used Inkscape to create the 2D drawing and set the colors required for the Trotec laser machine, but I faced some problems, such as the sketch not importing completely as it should. So, I decided to use Rhino, which solved the issue and made it easy to set the design colors.

In Rhino, I changed the edge line color to green for cutting and red for engraving, set the linetype to Continuous, and made sure the print width was set to Hairline.

rhino settings
Then I imported the 2D drawings into Trotec software for cutting with the laser machine.
trotec software

4. Cutting process

I used the Trotec laser cutting machine to cut the parts of the car from 3 mm MDF.
Here are the settings I used for cutting 3 mm MDF.
  • Power: 70%
  • Speed: 0.4
  • Z Offset: 0
laser cutting
Then I made a test cut for the slots to make sure that the dimensions were correct and the parts would fit together.
test print
Here is the cutting process.
After choosing the best dimensions, I proceeded with the final cutting process. I edited my 3D model based on the test results to make sure that all the parts would fit together perfectly. I took advantage of the parametric design, so I changed all the slot dimensions with one small adjustment. Here is my parameter list.
parameters list
Then I cut all the parts of the car.
cutting process explosion

5. Assembly

After cutting all the parts, I started assembling the car.
Here is the final result.
final result Return to the Week 3 page