Laser Cut 2D Ornamental Pattern on Cardboard

For this project, I laser cut two design variations. Both designs are made in Rhino/Grasshopper by following the steps in the grasshopper overview tutorial, and then experimenting with the parameters.

• Rhino7 & Grasshopper
• the Pufferfish extension for Grasshopper: download from Food4Rhino, and install it into Grasshopper's component/libraries folder.
• Adobe Illustrator
• Laser cutter
• Cardboard

For the designs, I primarily follow the step in the overview tutorial.

• Create new model with units in mm.
• Create and set two points on the xy-plane, p1 being the origin, p2 being the upper right point of the design.
• Use the Python scripting component to general a grid of points on the plane:
• rx being the input that determines the number of points in a horizontal row
• p1, p2 determine the width and height of the design
• mod is the parameter the determines point distribution (only some points in the grid are created while others are omitted)
• mtype selects between 4 different methods to calculate point distribution for the design
• I ended up choosing mtype == 2 for my designs

                elif(mtype == 2):
                    if((i*j) % mod) == 0:  # calculate point distribution
                        pt.append(rs.CreatePoint(x,y,0.0))  # create point if condition satisfied

• To create curves with our grid of points, add a distant function to the Python script, and add a dist input variable, so that points within dist can be connected to each other.

      if(dist2(pt[i],pt[j])<d2):  # if pt[i] and pt[j] are within dist
          ln.append(rs.AddLine(pt[i],pt[j]))  # create line connecting pt[i] and pt[j], append to ln

• The output list of lines/curves from the previous step should go through the Offset Curve component from Pufferfish, so that they are converted to a set of closed rectangular curves (a volumetric solid), so that the design is fabricatable by the laser cutter

I tried out many combinations of the parameters. When mtype == 2, it seemed to generate the most interesting shapes and geometries, so that's the point grid calculation method of my choice. The pictures show the parameters I used for my laser cut designs.

For some geometries that are more complex, the lines can interfere with each other and with the design details. A lot of designs that looked interesting in Rhino did not end up being interesting to cut, as we will see in Step 5: What Didn't Make It To The Laser Cutter.

After finishing adjusting the parameter in Grasshopper, I baked the curves onto a layer in Rhino, and exported them to as an illustrator file.

In Illustrator, I used the pathfinder tool unite to union all curves to produce a cuttable, solid pattern.

This is the part that felt somewhat unpredictable. I found it rather difficult to envision the after patterns, especially with smaller details. My mind was definitely more preoccupied with all the dense, intersecting lines, while in actuality the busiest areas in the "before"s ended up being white spaces in the "after"s.

Before cutting, the stroke color of the design needed to be changed to red (rgb(255, 0, 0)), and the stroke weight to 0.05pt.

In the laser cutting software, I used manual control, selected red, and set the power to 60%, speed to 50%.

design10 took a bit longer than design6 to cut, as it had many more polygons.

Overall, I was satisfied with these two cuts. I am pleasantly surprised by the precision of the laser cutter. Although small geometries on the digital designs were almost lost on the cut cardboard, e.g. the small dots, they are tiny but are definitely cut through.

So instead of using a distance function to generate curves from the point grid, I also tried using the Delaunay edges component to create designs. Ultimately, the results didn't feel as exciting.

The primary issue to result in uninteresting designs mainly came from over-complicated, overlapping lines in the Rhino design that left little to nothing to laser cut after the uniting step in Illustrator. From trials and errors with these "failed" patterns, I was able to cut down on complexities in my design to create more interesting pieces.