Weekly Assignments Final Project About me

Week 3 | Computer Aided Cutting.

Overview

This week I worked with two computer-controlled cutting machines: the Epilog Laser 40W CO₂ for laser cutting and a vinyl cutter. My individual assignment built directly on work I had previously completed during the Digital Bodies week of Fabricademy. I'm excited to tie in my Fabricademy knowledge during this week's assignment because it also includes the use of creating a digital and exploring concepts in bringing reality into the digital space and then back to reality in a new material.

Group Assignment : Remote

I completed this week's characterization independently. My lab does not have an in-person cohort for group work at this time. The documentation below reflects my individual characterization of the Epilog 40W CO₂ laser cutter and a vinyl cutter.

Safety Rules for Preparing to Use the Epilog 40 Watt CO2 Laser

  1. Ensure that you're dressed appropriately. You should always have on closed toe shoes when working with the laser cutting machine. Other fashion considerations include tying up any drawstrings that dangle from your clothing, tying your shoes, securing any loose clothing, and removing any items that are not secured to you (any items that have fallen off of you before).
  2. If you're an individual that has light sensitvities, especially related to your eyes, please be sure to grab a pair of photo sensitive glasses.
  3. If you have a history of asthma or sensitivities to smells, or small particles I'd recommend putting on at least one face mask (located right next to the machine).
  4. Before pressing play or go on any project on the laser cutting machine, please handle any bio related needs. Go ahead and use the restroom, blow your nose, grab something to drink or eat (outside of the lab), and any other relevant business. You are not allowed to leave the laser area (marked in red on the floor) while the machine is running.
  5. Located right next to the computer that sends design files to the machine is the machine guidebook. The guidebook is always set to the materials settings page where I have highlighted the machine type that is available in the lab. You can utilize the design software on the computer to find the correct design settings for your machine and material but it is recommended that you also double check within the book to make sure that you have chosen the correct machine settings for the material you are working with.
    6. You also want to go ahead and take not of all of the safety features for fire safety. There is a fire exstinquisher located between the two laser machines for easy access. There is also a fire blanket located right above the mouse on the computer table that is to the left of the machines.
  6. Next to the machines is my office, on the wall right next to my office door (to the right of the door) is a button. This button is very important. Pressing this button during an emergency is very important as it lets others in the building know that something is going on in the lab and that they should exit the building. Please understand the importance of this button. The button also allows the indibiduals located at the Georgia Tech Research Institute know that there may be a concerning situation within the campus.
  7. The exhaust system will be turned on every day. If for any reason you notice that the exhaust system is not on and active, please notify me before starting any projects. The exhaust system needs to be on before any project is started.
  8. The Co2 pumps also need to be turned on. These will be turned on. If for any reason they are not turned on before you begin your project, please notify me before starting any projects.
    9. Make sure to understand all of the above before starting a project within the FVSU Fab Lab.

Materials that cannot be used

The FVSU library only allows the use of materials that have been purchased by the FVSU Fab Lab manager. You can purchase needed materials from the FVSU Fab Lab or utilize scrap items located within the lab. We do not currently allow anyone to bring in outside materials for safety reasons. Please see a list of materials below that should never for any reason be used in the FVSU Fab Lab's laser cutting area.

  1. Polycarbonate
  2. PVC (this produces chlorine gas, DO NOT use)
  3. Any materials with unknown coatings.

Safety Rules for Using the Epilog 40 Watt CO2 Laser

  1. Never leave the machine unattended during a cut. Stay present and watchful. Utilize the camera system via the epilog dashboard on the computer screen or utilize the viewing area within the machine. Keep your eye on the flame. If the flame is ever longer than the first line in your pointer finger, pause the cut, and ask for assisstance.

Parametric Construction

My parametric construction kit was designed using Fusion 360. The kit is directly derived from the interlocking body-form slices I produced during Fabricademy's Digital Bodies week.

During Digital Bodies I used Fusion 360 Slicer (now Autodesk Forma Slicer) to slice a MakeHuman-derived 3D body into interlock cross-sections sized for 3mm material. This week I revisited those files, measured the actual kerf, and updated the slot offsets to achieve a proper press-fit without adhesive.

Why Fusion 360

The Fab Academy evaluation explicitly rules out Inkscape's clone tool as parametric design. Fusion 360's Slicer uses true parametric relationships.

Fusion 360 Slicer

There are a few things that make Fusion's Slicer unique

  1. Material thickness can be entered as a variable
  2. Kerf offset can be entered as a variable.
  3. The slot dimensions update automatically when values change in the material thickness and kerf offset values.

The Paramaters

Paramater Value What it Determines
Material Thickness 3mm All slot depths
Kerf Offset 0.1 mm Slot Width = Material Thickness - Kerf Offset x 2
Slice Count 12 The number of interlock slices that will be generated

Design Process

Feel free to check out my Fabricademy documentation for the cocnept of moving from a 3d scan to a digital body. Below i'll describe how you move into the digital design space with that information and utilize it to create something out of a new material using a laser cutter.

I chose to create a annequine both full and half scale with unique measurments rather than an off the shelf standard. The current DIY mannequin process uses materials that are neither earth-friendly nor durable across multiple uses. My digital body approach was a path toward a sustainable, customized, and repeatable alternative.

Overview

  1. Imported the finalized OBJ body mesh from Blender into Fusion 360's Slicer extension.
  2. Set material thickness to 3 mm and scaled the model to fit the Epilog's bed dimensions.
  3. Modified slice directions to eliminate red error regions (overlapping geometry).
  4. Updated the slot width using the kerf value measured in the characterization step.
  5. Export flat plans as DXF files for laser cutting.
  6. Before exporting those plans I made sure that the pieces were arranged in a way that would allow me to minimize material waste.
Fusion 360 Slicer Images

Software used to build the 3d Body

Tool What I Used it For
MakeHuman Generated a parameterized 3D human model matched to my measurements and proportions.
Hyper3D Sculpted additional proportion adjustments using symmetrical brush tools.
Polygonal (web) Cleaned and remeshed the mesh; exported as OBJ.
Blender Used Boolean tool to isolate the torso at half-scale; saved as OBJ.
Fusion 360 Slicer Converted 3D body into interlocking 2D laser-cut slices.
Prusa Slicer Tested scale and repaired open vectors before moving to Fusion 360.

Scale Decisions

I tested two scales in Prusa Slicer: 205% (2h 15m print time) and 410% (9h 27m print time). For the laser-cut press-fit version, I chose half scale to ensure the process works without utilizing a lot of the lab's materials.

Laser Cutting Process

I used 3mm acrylic for this project

Parameter Value
Power 100%
Speed 20%
Frequency 5000
Focus Auto
Passes 2
Air Assist On

Step by Step Workflow

  1. Set focus: placed the material flat on the bed and used the Epilog's focus tool to set the correct focal distance.
  2. Open the file in inkscape, and hit "print". The FVSU Fab Lab is set to send the document directly from Inkscape into the Epilog Software.
  3. Utilizing the epilog software, choose 3mm acrylic from the materials library. Double check those settings with the book right next to the computer.
  4. Send the cut to the machine
  5. Started the cut. Stayed present for the full duration of the job.
  6. Waited for fumes to clear before opening the lid. Removed and labeled the cut pieces.
Cut Pieces on Laser

Vinyl Cutting A PCB for Acrylic

My design is a PCB using the circuit that I created for the wearable portion of my final project

Machine & Settings

Machine Brother Scan N Cut
Blade Depth -1
Pressure -6
Speed 0
Material Copper Tape (with sticker back intact)
Passes 1
Adhesion Standard mat adhesion, blue painter's tape to ensure the copper tape does not move

Process

  1. Prepared (check out my electronics design week for info on the schematic design) and exported the design file as SVG / DXF.
  2. Loaded the copper tape into the machine and set origin.
  3. Ran multiple test cuts on a small area to check blade depth before cutting the final successful design.
  4. Cut, weeded the excess vinyl, and applied transfer tape.
  5. I used a scrap piece of acrylic that is roughly the size of the schematic to place my "sticker" PCB.

Files

File Description
Wearable Wristband — Inkscape Traces Inkscape Traces
DXF Form — Fusion Slicer Fusion Slicer