Sean Farrell HW#2 | Laser Cut Iris Box

For this homework I wanted to make something that could do something cool and was fun to watch. I found that an iris box would meet my creative design criteria. With the help from our class TA Jamie I was able to find a design on the Thingiverse.

Figure 1. Top of iris showing the mechanical parts.

In my first attempt I tried to use the Zing to cut out my design on cardboard. I also altered the original iris design by adding a picture at the bottom plate. I was super excited to start cutting out my design until I encountered a problem. Every time I tried to cut out the top of the iris, which had tightly packed intricate cuts, it would catch the cardboard on fire. I also found that my raster settings used to engrave my image were off. I ended up just burning a blackish square in the cardboard. It took me several hours working with Ryan and Bryan in the shop to finally get the Zing raster and vector setting correct. The cardboard laser cutouts for the iris are shown in Fig. 1-2. In order to get the iris mechanism to kind of work I needed to add ~10 12mm bolts. As you can see from Fig. 2 I ended up not finishing the cardboard engraving of the image.

Figure 2. Base of iris with side walls.

Next, I cut out my design into ~1/4 in plywood using the Zing. This time I did not encounter any fire problems but I did have trouble getting the image engraving to show up. It ended up looking more abstract than detailed. I talked to Ryan and Jamie and they both suggested that I try using a lighter material and speeding up the rastering while decreasing its power. The individual pieces of the iris box are shown in Fig. 3-7.

Figure 4. Bottom of iris box with side walls.

Figure 3. Top view of closed iris.

Figure 6. Side view of iris box with wall supports hot glued in place.

Figure 5. Underside of the iris box top with it full closed.

Figure 7. Underside of the iris box top with it full opened.

I found that the original design just used friction to hold the bolts in place. This did not work with my design so I resorted to adding a nut to the bolts in the tracks and hot glueing the other bolts in place. This seemed to work great and also increased the designs robustness.

The final completely put together iris box is shown in Fig. 8-11. Overall, I am very happy with how the design came out and fit together. It fits in the hand nicely and does open and close the aperture. The only thing I would say needs to be improved is the image engraved on the bottom of the box. Definitely a fun project to make!!
-Sean Farrell