3. Computer controlled cutting

Tasks for this Week:

Individual Assignment:

• Cut something on the vinyl cutter
• Design, laser cut, and document a parametric construction kit

Group Assignment:

• Characterize your laser cutter’s focus, power, speed, rate, kerf, joint clearance, and types

Trying Out Designs for Vinyl Cutter

This week focused on learning how to operate laser cutters and vinyl cutters. We used laser cutters to engrave and cut different shapes on various materials like cardboard, wood, and acrylic.

Inkscape is the tool we used for vector modeling designs.

Different colors are assigned to different functions. Red indicates cutting, while black indicates engraving.

When using the vinyl printer, we need to vectorize the file and define paths before uploading.

We could design according to our ideas. I designed a Transformers logo using Inkscape to vectorize the image and downloaded the Transformers font. The link is listed below.

To vinyl print an image, ensure it’s of standard quality. Go to Path and select Trace Bitmap, and Inkscape will handle the vectorization process.

This is the machine that we use for vinyl printing . Roland To operate the vinyl cutting machine, turn it on using the blue button located at the bottom-right of the control panel.

The machine will prompt you to select the material type—either roll or piece. For a piece, the machine will measure its exact dimensions. For a roll, it will only measure the width. Load material through the back, similar to a printer. The presser foot can be lifted up and down using a lever for feeding the vinyl paper.

Make sure the two wheels are within the white striped areas on the machine to avoid a “Bad Position” error.

From Roland user manual https://downloadcenter.rolanddg.com/contents/manuals/GX-24_USE_EN_R5.pdf

The values that we set for the vinyl cutting are as follow the power is 100 and speed is 2

this is the basic image of the components.

vinyl printing is done using Fablab Mods . Open the Mods and run the the bash script.

After mods opens on the browser right click to select programs > open server program >select the appropriate machine in our case its Roland ( vunyl cutter ) GX - 24

input the svg file that you want to vinyl cut.

Then right-click on the page, navigate to “Programs,” select “Open Program,” and choose “GX-GS 24 Vinyl Cutters - Cut.”

• Select the origin point based on how you positioned the vinyl in the cutter.
• Set the DPI to “1000”.
• Click the “calculate” button.
• Check your image path in the “vectorize” box. Then click “open socket” followed by “send file to device” to start cutting.

To transfer the design, apply a layer of transfer paper (in this case, masking tape) on top of the remaining design. Make sure to firmly rub the design onto the transfer paper.

Use tweezers and a handblade to carefully remove the excess vinyl sticker material

Remove the masking tape by taking it to the area where you want to place the vinyl and rubbing it firmly so that the vinyl sticks to the laptop (in my case here).

This is what i printed .

LASER CUTTING

Laser cutting is a precise manufacturing process that uses a focused laser beam to cut materials. For our lab work, we used an Trotec cutter which can both cut and engrave various materials like wood, acrylic, and cardboard. The key parameters we need to consider when laser cutting are power, speed, frequency, and focus distance.

These parameters need to be carefully calibrated based on the material type and thickness to achieve optimal cutting results. For example, harder materials like acrylic typically require higher power settings and slower speeds compared to softer materials like cardboard. The focus distance is particularly crucial as it determines the precision and quality of the cut.

The laser cutter’s focus can be adjusted using the autofocus feature or manually using the focus gauge. In our lab, we typically maintain a focus distance of 7.5mm from the nozzle to the material surface for optimal cutting results. This consistent focus setting helps ensure clean cuts and precise engraving across different projects.

When operating the laser cutter, safety is paramount. We always ensure proper ventilation and wear appropriate safety gear including protective eyewear. The machine’s exhaust system must be running during operation to remove potentially harmful fumes and particles.

The laser cutting process involves several key steps, beginning with creating and programming the cutting pattern. Once programmed, the machine executes the cutting sequence.

• Laser generation: A resonator converts power supply energy into a laser beam.
• Laser amplification: Two mirrors at the head’s ends intensify the laser beam as it passes through an amplifying medium.
• Laser direction and focus: Either fiber optic cables or focusing head mirrors guide the laser beam. A lens then concentrates the beam’s energy to achieve cutting power.
• Gas supply: The nozzle releases gas to clear molten material from the cut line (kerf).
• Cutting: The focused laser beam melts and vaporizes material while the cutting head moves along the programmed pattern, creating the kerf. Sometimes the material moves instead of the cutting head.

Types of laser used in our lab

• CO2 Lasers: These lasers cut non-metallic materials including wood, acrylic, plastic, fabric, leather, and paper. They can also cut metal when it has a special coating to prevent reflection.
• Fiber Laser Cutting: These high-efficiency lasers excel at cutting metals, including both ferrous metals like steel and non-ferrous metals like aluminum, copper, and brass.

1. To start the machine, first turn on the power supply, then turn the knob to the right.
2. Ensure the lid is closed during initialization. Wait for the laser to return to its home position and listen for the confirmation beep. Once the machine has finished calibrating and booting up, you may open the lid.
3. Position your material in the workspace, preferably at the upper left corner (origin point 0,0).
4. Navigate the laser head using the arrow keys on the machine’s interface. The up/down arrow keys marked with the “Z” symbol control the laser head’s vertical movement along the z-axis.
5. Proper z-axis setup is crucial for laser focus. Place the focus tool’s gold lip on the small ledge of the laser head, allowing it to float lightly. Adjust the bed height using the z-axis controls until the focus key just barely detaches from the laser head.
6. To auto-focus the laser head, simultaneously press both the up and down arrow keys (marked with “Z”) on the machine panel.

Software Setup

Trotec JobControl is laser software that prepares graphics and text for laser engraving or cutting. It receives print jobs from image editing software and arranges them on the laser cutter’s bed.

• You can use the job center coordinates to position the laser head. The software offers complete customization of power, velocity, frequency, material type, and design placement.
• To begin, open the menu and select “Import from File” to load your design.
• Position your imported design by setting the origin coordinates.

• Choose your material from the list. For our test, we selected “cardboard”.

• Access the “material template” (or press “Ctrl + M”) to set the processing parameters for each color in your design.

Click the play button at the bottom to start the job. The design will be engraved, or cut on your chosen material. If the material isn’t cut properly, repeat the cutting process. If the joints don’t fit correctly, adjust the kerf value and print again until you achieve the perfect result.

Parametric Construction kit

A parametric construction kit is a modular system where parts are designed with adjustable parameters, allowing for flexible and customizable assembly. Using laser cutting technology, we can create precise interlocking pieces that form various structures. The key advantage of parametric design is that dimensions and configurations can be easily modified to suit different needs while maintaining consistent assembly methods.

graph TD
    A["Start Parametric Design"] --> B["Open Fusion 360"]
    B --> C["Create New Design"]
    C --> D["Start Sketch"]
    D --> E["Define Parameters"]

    E --> F["Create Base Components"]
    F --> G["Add Constraints"]

    G --> H["Use Parameters"]
    H --> I["Test Assembly"]

    %% Branch for Parameter Management
    E --> J["Parameters Panel"]
    J --> K["Define Variables"]
    K --> L["Set Relationships"]

    %% Branch for Component Creation
    F --> M["Create Features"]
    M --> N["Pattern Elements"]
    N --> O["Add Joints"]

    %% Advantages Branch
    A --> P["Advantages"]
    P --> Q["Easy Modification"]
    P --> R["Reusability"]
    P --> S["Time Saving"]
    P --> T["Consistency"]

    %% Final Steps
    I --> U["Export/Share"]
    U --> V["Documentation"]
    V --> W["Final Assembly"]

We use Fusion 360 for parametric designing. Below I will show how the design flow works:

Draw the shapes you want to laser cut, click on “Modify,” and look for the parametric tab. From there, you can adjust all the parameters as needed.

This is how parameters tab look like

Use the shortcut key ‘E’ for the extrude command. After extruding the joints to the desired thickness, arrange the pieces using the arrange option. You can find this under Sketch > Modify > Arrange. Enter your available cardboard size, and the software will automatically arrange the pieces to fit within those dimensions. select the plane before you are going to arrange .

Export the component as a DXF file by right-clicking on the arranged sketch and selecting the “Export as DXF” option.

Export the DXF file to Inkscape, then use Ctrl + P to print, which will send the file to JobControl for laser printing.

the below things are what i made using the cardboard pieces . I made a tortoise with cardboard.

Reference Image .that i took as a reference . The final result is on the side.

CONCLUSION

In this lab session, I successfully learned about laser cutting technology and parametric design principles. Through hands-on experience with the Trotec laser cutter and Fusion 360 software, I gained practical skills in creating precise, customizable components. The combination of theoretical knowledge and practical application has provided me with a solid foundation for future projects involving laser cutting and parametric design.

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Last update: February 18, 2025