3. Computer-controlled cutting

Parametric construction kit

Designing the parametric construction kit

For designing the laser-cut parametric construction kit, I used Fusion 360’s parametric design system. I hadn’t previously used this before, so I read and watched this tutorial on the Autodesk website.

The main points I took away from this were:

1. You can create and modify parameters in Fusion 360 via the Modify -> Change Parameters dialog.
2. Parameters can be referenced by most number inputs in Fusion 360, such as sketch dimensions, extrusion lengths, and even other parameters!

After trying out parametric design for a bit, I started designing my construction kit. I decided to use chamfer joints for connecting the design together.

For the construction kit, I decided to make a circle, a hexagon, and a rectangle, all with chamfer joints.

My initial plan was to design everything in a single sketch and then export it as a DXF file before printing the design on the laser cutter. However, I ran into an issue doing this: Fusion 360 does not keep a timeline of sketch designs.

This made parametric design more annoying to do in general, so I decided to use sketches minimally and instead extrude the shapes I wanted to make as bodies before using solid tools to modify them.

For parameters, I defined the lengths of each shape, the cardboard thickness, the laser kerf, and the joint width and length:

For the circle, I created a sketch of the base shape, then I extruded the base shape without joints first. Then, I made one joint on each shape by creating a rectangle on top and negatively extruding it to create a hole.

After that, I used the chamfer tool on the sides of the joint, and used a Circular Pattern to reflect the joint onto every side of the shape.

Each Circular Pattern required an axis to revolve around, so I had to construct an axis which was perpendicular to the bottom face of each shape and that passed through the point. I designed the hexagons in a similar fashion to the circles, but I used the Circumscribed Polgyon tool to create the bottom face. I then used a Rectangular Pattern on both the hexagon and circle to replicate the shapes.

The rectangles could not use a circular pattern, so I had to create construction planes and mirror each joint across the planes instead:

To print the design, I created a new sketch on the XZ plane and then projected the 3D bodies into the sketch. This made a flat outline that the laser cutter could follow. After that, I right-clicked on the sketch in the Browser and used Export as DXF to generate a DXF file for the laser cutter. After I generated the DXF file, I opened it in CorelDRAW on the computer connected to the laser cutter. and then sent it to the Epilog Job Manager.

Then, I printed it out on the laser. This is what the pieces looked like after being cut out:

Making things with the pieces

Here are some examples of things I made with the construction kit: “V-wing starfighter” “dinosaur”

Vinyl cutting

Silhouette Studio

To do the vinyl cutting, I decided to cut out and print a sticker of the Python logo because I thought that would be nice. I started off by downloading a python logo svg from Wikimedia Commons.

I used File -> Open in Silhouette Studio to import the file: The “Fill” tab in the Send menu let me select which part of the design to cut. In this way, I was able to cut a multicolored design by cutting the individual pieces and then using transfer tape. To cut each design, I clicked on the “Send” button in the Send menu at the bottom after selecting the colors I wanted to cut.

Cutting the vinyl

After I had cut both the yellow and blue parts of the sticker, I used the transfer tape to help me take them off of their original vinyl sheets:

Then, I applied the sticker to the lab window, as shown below:

Files

Here is a download link to my relevant files from this week. This contains my Silhouette Studio files and my Fusion and dxf files for laser cutting.

Group project work

My group project for Week 3 was with Collin and David (link). I contributed by working on characterizing the focus, power, speed, and rate of our laser cutter.