week03 | Computer-Controlled Cutting
Overview
Linked to the group assignment page. Reflected on your individual page what you learned of your labs safety training Explained how you created your parametric design. Documented how you made your press-fit construction kit. Documented how you made something with the vinyl cutter. Included your original design files. Included hero shots of your results.
Group assignment
For this week, in group assignment, we began by required laser safety training to ensure safe and proper operation of the machine.
Following this, we conducted a series of systematic tests on the Vector laser cutter to evaluate how different parameters affect cutting performance. The primary focus was to see the impact of speed and power settings on laser cutting quality. These tests were performed on 3 mm thick MDF material. In addition to MDF, we also tested plywood DPI (LPC) to evaluate how resolution settings influence engraving quality. Throughout the assignment, we performed and documented the following tests: focus test, power test, speed test, rate test, what is Kerf and measuring it, joint clearance test, and DPI (LPC) test.
Individual assignment
This assignment includes two main parts: laser cutting, from parametric design to cutting, and vinyl cutting, from design to cutting.
Parametric design
For the parametric design I used Fusion 360.
Before starting the sketch, I saved the project and gave the design file a proper name to keep the work organized.
I began sketching by pressing L (Line tool). Using simple lines, I can create almost any 2D shape.
Sketch the overall shape of the model without worrying about accurate dimensions at this stage:
After finishing the rough sketch, I defined parameters. From the Modify tab, I selected Change Parameters (fx).
I created all the required parameters for the design. During the FabLab training, we used material with a 3 mm thickness, and the measured kerf was 0.19 mm.
Then I returned to the sketch and pressed D (Dimension tool). I applied dimensions using the parameters I had already defined.
I followed the same process for both parts of the model to keep the design consistent.
From the Constraints menu, I selected the Equal constraint and applied it to the dimensions that must stay identical.
After applying all necessary constraints, the sketch became fully defined (all lines turned black).
I defined the slot width using the formula:
material_thickness - kerf
This formula ensures the parts fit together properly after cutting.
Next, I extruded the sketches using material_thickness as the extrusion value to create the 3D model.
To use the model in practice, it needs to be exported in a format compatible with Inkscape:
I selected the correct export size settings to ensure accurate scaling.
I disabled the legend and then clicked Export.
The final file was ready to be opened in Inkscape for laser cutting preparation.
Finally, I also uploaded the original design files in .STL and .F3D formats for documentation and future editing.
Cutting parametric design
For cutting, I used EPILOG LASER FUSION machine in Oulu FabLab, before cutting the final model, I performed a test cut to verify the fit.
In the original design, I assumed a material thickness of 3.00 mm and a kerf value of 0.19 mm (from earlier group calibration tests).
Before cutting the final model, I performed a test cut to verify the fit. The first version (using 3 mm thickness and 0.19 mm kerf) did not fit well (see image below).
To find the accurate kerf for this material and settings, I cut a 30 mm test square. After cutting, it measured 29.88 mm with calipers.
The actual material thickness was 2.91 mm (slightly less than nominal 3 mm). For a good press-fit slot, the designed slot width should be:
I returned to Fusion 360, updated the parameters to material_thickness = 2.91 mm and kerf = 0.12 mm, and recalculated the slots using Slot Width formula.
Here is the updated sketch after the correction:
After adjusting the parameters, the model was ready for laser cutting.
I export the model as a pdf file that is readable for printer. To prepare for cutting, I opened the file connected to the laser cutter and pressed: Ctrl + P → Properties → Advanced (Load Material) I checked the general settings for power and speed, then pressed OK. I placed the HDF material inside the laser cutter and positioned it properly. I set the origin to the top-left corner of the material using the Epilog panel (Job Control → Origin). Then I did focus calibration by placing the aluminium focusing piece on the material surface and lowering the bed until the aluminium piece just touched the lens nozzle.
Then I started the cutting process.
After the cutting was finished, I removed the pieces carefully from the machine.
Here are the final laser-cut parts assembled from the parametric design. It can be used as a toy for kids, for creativity.
The final result shows that adjusting the kerf value improved the fitting accuracy of the joints.
Vinyl Cutter
At Oulu Super FabLab, we use the CAMM-1 GS-24 vinyl cutter (shown below) to cut thin vinyl sheets for making stickers, decals, and labels.
To prepare the file and cut it using the vinyl cutter, I used Inkscape to create and modify the design. I decided to use the logo of my favorite football club as the model file. After downloading the logo, it needed to be properly prepared for vinyl cutting.
First, I placed the downloaded file in the same directory as my Week 03 assignment files to keep everything organized.
Importing the file into Inkscape
The logo file was imported into Inkscape using the File → Import option.
Since the file was already in SVG format, there was no need to convert it from bitmap to vector, which is usually required for raster images such as JPG or PNG.
Next, the logo needed to be cleaned and prepared for cutting. I started by ungrouping the design. This process was repeated multiple times until there were no remaining grouped objects left in the file:
After ungrouping, I converted all objects into paths by using Object → Object to Path. This step is important because the vinyl cutter can only recognize paths, not shapes or text objects:
Then, I combined all the paths into a single shape using Path → Union, which ensures that the cutter treats the design as one continuous object.
Adding extra elements to the design
Instead of cutting only the logo, I decided to enhance the design by adding a few sticker elements available in Inkscape, such as football icons.
After finalizing the layout and checking that all objects were properly aligned and converted to paths, I saved the file for vinyl cutting.
Vinyl Cutting Process
Now it was time to do some hands-on work by preparing the vinyl material and inserting it into the vinyl cutter. Before cutting the final design, we performed a test cut using a small ball sticker to ensure that the blade depth, pressure, and alignment were correct.
Sending the design to the vinyl cutter
For cutting the complete design, I imported the prepared file into Inkscape on the computer that had the vinyl cutter software installed.
By following the steps below, I sent the design from Inkscape to CutStudio, the vinyl cutter software. The origin point of the vinyl cutter is at the bottom left, so when the file is transferred from Inkscape and opened in CutStudio, it is automatically placed at the origin.
At this stage, I faced the following error:
After searching online, I found that the error occurred because the default page size in the vinyl cutter software was smaller than my design. To fix this, I manually resized the working area to match the size of the vinyl material.
The main logo and one football sticker were transferred correctly to CutStudio. However, the rest of the sticker elements did not transfer properly, so I copied and pasted them manually. This worked, but it is not the correct or recommended workflow, as it may cause scaling or alignment issues.:
Cutting and finishing Once the design was ready, I loaded the vinyl into the cutter, making sure it was properly positioned. I aligned the edge of the vinyl with the guide, adjusted the pinch rollers to sit on the white grit marks, and double-checked that the material was flat and secure. After verifying the settings, I sent the design to the cutter and carefully monitored the first few passes to ensure a clean, precise cut.
After the cutting process was finished, I removed the vinyl sheet from the machine and trimmed it using scissors, and I used transfer paper to move the cut sticker from its backing onto the final surface.
The next step was weeding, where I carefully removed all the unwanted vinyl parts using tweezer, leaving only the final design:
Finally, the vinyl sticker was ready:
This is the final result, also used as the hero image for this assignment:
Reflection
This week I practiced and improved my skills in computer-controlled cutting, machine testing, and parametric design. Using Fusion 360, I created a parametric model based on two key parameters: material thickness and kerf. After exporting the cutting files, I tested the design and adjusted the tab widths based on an actual measurement from a test cut. The measured kerf was about 0.12 mm, which was smaller than my initial estimate of 0.19 mm (from group work), and updating the design based on this measurement made the joints fit much better.
During the group work with the vector laser, we tested several parameters including focus, power, speed, rate, kerf, joint clearance, and DPI/LPC using 3 mm MDF and plywood. This exercise helped me understand how small adjustments in machine settings can affect cutting quality and engraving results. Working with the Epilog Laser Fusion also reinforced the importance of following safety procedures and always performing test cuts before cutting the final material.
For the vinyl cutting workflow, I prepared and cleaned an SVG file in Inkscape, fixed some formatting and transfer issues, and sent the file to the Roland CAMM-1 GS-24. I encountered a page-size mismatch at first, but troubleshooting it and running a small test cut helped me understand the importance of checking both the material setup and the software workspace before starting a job.
Overall, the key lessons from this week were the importance of measuring early and iterating the design, keeping file exports organized and consistent, and always running small test cuts to verify machine settings and alignment.
