Weekly Assignments Final Project About me Student Agreement

Week 3. Computer-Controlled Cutting

The Shadow Box

For the Computer Controlled Cutting week, I designed a modular Shadow Box. This project is ideal for demonstrating parametric design, as it requires multiple layers to fit perfectly within an external structure, accounting for both material thickness and the laser's kerf (material loss).

ONSHAPE & VARIABLES

For my parametric design, I used Onshape to create a model entirely controlled by variables. This approach ensures the design is adaptable to different materials or machines simply by updating the values in the Variable Studio.

Variable Studio

LAYER 1

I designed the parts using geometric constraints and dimensions linked to my variables. This ensures that every layer of the shadow box maintains its proportions when parameters change.

Sketching process

LAYER 2

I designed the internal silhouettes using parametric offsets. I defined the decorative marine shapes while ensuring they remained physically connected to the main frame, maintaining structural integrity for the press-fit assembly.

Sketching process

LAYER 3

Each layer was designed as a separate part but within the same Part Studio to ensure alignment. The circular window and outer frame are all driven by global dimensions.

Sketching process

LAYER 4

Based on the lab's characterization, I adjusted the Kerf value to 0.14mm. This precise offset is what makes the modular parts stay together firmly.

Sketching process

LAYER 5

Finally, I exported each face as a DXF file. These vector files are ready to be imported into SmartCarve, keeping the exact dimensions from the 3D model.

Sketching process

THE KERF CHALLENGE

To achieve a press-fit assembly that doesn't require glue, it is crucial to compensate for the kerf in the joints. Based on the Group Assignment characterization performed in our lab, we determined that the laser consumes material during each cut. Therefore, for the 2.7 mm MDF, I set a kerf of 0.14 mm, which was initially configured during the fit tests.

Sketching process

JOINTS AND TOLERANCES

I centralized all global parameters within the Variable Studio. This allowed me to use mathematical formulas such as (#Material) - (#Kerf) for the joint slots, ensuring the pieces fit tightly through friction. Finally, I exported my designs in DXF format, which is the standard file type for the laser cutter to interpret the vector paths correctly.

Tolerances

MACHINE SETUP

To guarantee safety and precision during fabrication, I followed the established protocol at FabLab Puebla for the CamFive CFL-CMA 1080K.

Setup

0.1 PREPARATION

Verified that the cooling system (Chiller) was powered on and had the correct water levels.

Setup

0.2 POWER ON

Inserted and turned the safety key. Released the emergency stop button (turning it clockwise) and activated the side switches.

Setup

03. MATERIAL SETUP

Placed the 2.7 mm MDF on the honeycomb bed, ensuring it was level and within the 1.20 x 0.60 m work area.

Setup

04. ORIGIN SETTING

Moved the laser head using the panel arrows to the desired starting point and pressed the "Origin" button. Adjusted the nozzle height (Z-axis) to a distance of 5 mm.

Setup

05. FILE IN SMARTCARVE

Imported the DXF file to the SamrtCarve software, ensuring units were in millimeters to maintain the parametric design's real scale.

Setup

06. LAYER ORGANIZATION

Used different colors to geometries: one color for engraving details and another for cutting. I used the "Put to Origin" command to align the pieces with the machine's starting point.

Setup

07. PARAMETER SETTINGS

Configured the layers based on previous characterization tests for 2.7 mm MDF:

  • Max. Power (%): 70.00
  • Mix. Power (%): 60.00
  • Work Speed (mm/s): 25.00
Setup

0.8 AREA TEST

Closed the lid and selected the "Go Scale" command in the software to verify that the design fit within the material and wouldn't hit the edges.

Step 9

09. START CUTTING

Once the fit was confirmed, I pressed "Start" in the software to transfer the file directly to the machine's internal memory and begin the process.

Setup

FINAL RESULTS

Success! The layers fit perfectly thanks to the parametric adjustments.

Final Shadow Box

Design Files

In this section, you can find all the downloadable source files for the modular Shadow Box project.

DXF

01. Layer 1

Download File
CSV

02. Layer 2

Download File
SVG

03. Layer 3

Download File
PDF

04. Assembly Guide

Download File
DXF

05. Kerf Test File

Download File
ZIP

06. Box

Download File

Laser Cutting Process

My Assembly Process

Vinyl Cutting: Marine Stickers

As part of the Computer-Controlled Cutting week, I explored the use of the vinyl cutter to create decorative elements. I decided to make a set of marine-themed stickers, using adhesive vinyl to achieve a professional and durable finish.

IMAGE VECTORIZATION IN AFFINITY

For this process, I selected a marine life silhouette image from the internet. Since the vinyl cutter requires vector paths to follow, I performed a vectorization of the image. I used a specialized tool to trace the bitmap and then exported the final result in JPG format to be processed by the machine's software, ensuring the lines were clean and ready for cutting.

01. IMPORTING DESIGN

To prepare the file for the Roland GS-24, I used the CutStudio software, where I started by importing my file into the workspace.

02. IMAGE OUTLINE

I used the "Image Outline" tool to trace the outlines and then applied "Outline Weld". This combined step identifies the edges and merges the overlapping paths into a single continuous vector.

03. SCALING

Adjusted the size of the set to fit the available vinyl width.

04. SEND TO CUT

Finally, I accessed the 'Print Setup' to select the Roland GS-24 driver and sent the file to the machine.

01. MACHINE SETUP

I turned on the Roland VersaSTUDIO GS-24, loaded the black vinyl roll, and adjusted the pinch rollers.

02. CUTTING & WEEDING

Once the machine finished the high-precision cut, I removed the vinyl from the cutter. I then performed the "weeding" process, using a cutter to carefully remove all the excess material, leaving only the desired marine figures on the backing paper.

03. TRANSFER PAPER

I applied a layer of adhesive transfer paper over the weeded stickers. I used a squeegee to apply pressure, ensuring the vinyl figures bonded correctly to the tape so they could be lifted as a single unit.

04. READY TO APPLY

Finally, I trimmed the contour of each figure individually. This allows for a much easier and more modular application when placing the stickers on the final surface.

FINAL RESULTS

Success! The marine stickers are ready to decorate. The precision of the Roland GS-24 is excellent for these small details.

Vinyl Design Files

Download the vector files used for the marine stickers.

AF

Affinity

Original vector design with all stickers.

Download AF
JPG

Marine Stickers

File for vynil cutting.

Download JPG

Vinyl Cutting Process Video

How was it?

This week was an intensive dive into the world of Computer-Controlled Cutting, and what I enjoyed the most was the transition from a 2D digital design to a physical, functional object. Seeing the Shadow Box pieces fit together perfectly after the laser cutting process was incredibly satisfying; it validated the hours spent on parametric design and showed me the true potential of these tools for rapid prototyping.

A key learning point throughout this process was understanding the concept of Kerf and why it is so critical in digital fabrication. I discovered that you cannot simply design with nominal measurements; instead, you must account for the material lost during the cut. By calculating this value through a kerf test, I was able to adjust my design to achieve a perfect press-fit connection.