Week 1: Computer-Controlled Cutting

Assignment: cut something on the vinyl cutter and make a parametric press-fit construction kit on the laser cutter

Modular Design

This week’s assignment got me thinking about how you could create design objects for a room that were modular and unique — could I build “kits” that people could put together in different ways to have a unique piece in their home while still originating from the same set of pieces?

Laser Cutting

With the goal of modular design in mind, I started playing around with curved objects in Fusion 360. I made 20-30 different curves and played around with different aesthetics — revolving, extruding etc. I liked the idea of creating modular lamp shades where you could have a kit of ~50-100 pieces that could be connected to make all sorts of different shaped lamps. Theoretically, this seemed possible since you could vary the order in which you place the horizontal cross sections (circular pieces) to create different curves. The trick would be to mathematically create these shapes such that they could use the same set of circular forms. I decided to use the week to create one such lamp so that you could remove/add pieces so it would take on different aesthetics. The sketch on the left illustrates the general idea.

With this in mind, I went to try and cut various simple curved and circular pieces on the laser cutter to get a sense of the slot width I should use. The cardboard thickness measured to be 0.157 inches, so I tried this first. The thickness seemed to be a bit too tight, so I decided to try ranges from 0.157 to 0.159. 0.158 proved to be a good width for the joints.

3D modeling the curves ended up being more difficult than I thought it would be. A lot of the curves looked terrible when I revolved them into a solid. After I got a piece I liked, I looked around for good ways to cross-section 3D models into pieces. I found a few tutorials on how to accomplish this using different tools:

Tutorial using 123D Make here
Tutorial using Fusion 360 to slice objects here

I played around with these to find something that worked well. 123D Make seemed to work great with some shapes, but it was difficult to export files from Fusion 360 to work with 123D Make. The direct “send to 123D Make” function caused my computer to run out of memory. Eventually, I found a way to export a file from Fusion 360 to 123D Design, modify it in 123D Design, and import into 123D Make.

I played around with a lot of different slicing approaches. I settled on a radial cross section and decided to have an even number of cross sections in both planes. After trying a few versions I settled on 28 slices radially and 10 slices horizontally. This seemed like the maximum point for the radial slices since beyond this, the circular cross sections would become too small to put together. I also wanted an even number of slices so I could remove some pieces to create different styled lamps with greater see-through area.

I thought I would be good to go after getting these elements to work but cutting these pieces on the laser cutter took much longer than expected. The export from 123D Make came in as tiny line segments which the laser was unable to cut. After spending about 3 hours debugging this with John, I ended up importing the 2D files in as PDFs and vectorizing them in CorelDraw. I Tried a couple test joints to see if the width I had determined earlier still worked. I ended up tweaking it a bit to get the joint size I wanted and was finally ready to print. While the longer pieces came out great, the circular pieces were difficult. The large cardboard pieces were curved and the laser cutter wasn’t able to cut all the way through in some parts. I ended up having to cut over it twice to get the cuts to work successfully.

Finally with all the pieces cut, I was ready to assemble the lamp. While the pieces themselves fit in well, it was really difficult to get the first set of pieces to stay. I also realized the circular pieces were REALLY close in size, so it was difficult to differentiate them. I spent a couple hours measuring and numbering each of the joints on the pieces. This made assembling a lot easier. When assembling, I tried a bunch of different configurations. I skipped every other row, every third row, and also the top and bottom. Eventually the style I ended up choosing kept all the pieces except the top and bottom. Once I got the first two pieces in opposing ends of the lamp, it was a lot easier to put everything together and they all fit together easily.

As a next step, I’d like to design more lamps with the same set of circular pieces. By ordering these differently, I could totally change the shape of the lamp. I started playing around with this in Fusion 360 by creating 2D circles with the given radii and creating different splines with them. However, I did not have time to create more lamps from these. A project for later!

Vinyl Cutting

For the vinyl cutting project, I wanted to continue with the idea of modular design. I thought about creating a design that was flexible so each person could make a unique version. I decided to go with a simple shape (hexagons) and put them in an arbitrary pattern in black vinyl. Then I used gold vinyl to cut out different modular pieces–full hexagons, triangles, trapezoids etc. After cutting the two, I used tweezers to place the gold pieces inside the black hexagon outlines in different ways. Theoretically, anyone could play around with these and make their own pattern. I think used the sticky backing to install the entire decal on my wall.

The difficult part in installing the decal was the thickness of the hexagons. Since they were really thin, the decal often tried to come off. I ended up using a credit card to press it along as I went. I think it would be fun to print a bunch of different smaller modular pieces of the hexagons so they can be fit together in different ways as well to create all sorts of patterns on the wall.