For this project we were tasked with using the Epilog M2 and Fusion Pro laser cutting machines at the OEDK to create a box from a sheet a wood that can hold itself together without the use of glue.

To start, we first need to create .ai files in Adobe Illustrator to create the paths needed to cut out and engrave the panels of the box. We used https://en.makercase.com/#/ to create the panels of the box needed to make a 4″x4″x4″ box that can hold itself together. Before we can create the panels to cut out, we first needed the thickness of the sheet of wood and the kerf of the laser to ensure the panels can fit together without being too loose.

Using a digital caliper I first measured the thickness of the wood which came out to 1.855 inches. To find the kerf of the laser I used the kerfBox.ai file available on canvas to find out how much the path needed to be displaced to get the right measurement when cutting out the panels.

The gap left by the laser came out to 0.2055 inches, which when divided by 10, gave me a kerf value of about 0.02 inches. After getting my kerf value I was finally able to start making some test runs to see how well my panels would fit together. To conserve my wood, I tried cutting out three sides of a 2″x2″x2″ to see if my kerf value was the right amount, but I quickly found out my kerf value was too large and the panels were unable to fit together.

Seeing that my kerf value was too large I tried using a value of 0.005″ based on a display model in the laser cutter room to see if that would help make my panels fit together. I also decided that using the path of a 2″ box was also contributing to the problem and switched over to 4″ panels. The result of making these changes created 2 panels that were able to fit together but were slightly loose so I increased the kerf value to 0.007″ over the next few trials to get the right amount of displacement.

Now that I had the right values to make my box the next step was making sure the laser settings were set properly to cut through painter’s tape. Since I had planed on using tape to limit the amount of burned edges I attempted multiple engraving runs to find the best setting for engraving through. My first run consisted of setting my power setting to 25% and speed to 50% to see how normal settings would deal with tape and the results can be seen in the following image.

Seeing that a few sections weren’t able to be engraved by the laser cutter, I raised the amount of power to 50% but still had problems especially in areas where the tape overlapped. After my second engraving attempt I decided I was ready to cut out the 6 panels of my box and created the final version of my .ai file that would cut out my box.

For my final run I set the engraving settings to 75% power and 75% speed to ensure the laser cut through the painter’s tape and set the vector settings to 7% speed 100% power and 10% frequency. Before running my file I added tape to where I thought the edges of the panels would be and on the location of the two panels that would be engraved. After cutting out my panels I made sure they were able to fit together and removed the remaining masking tape leftover.

Overall I was really satisfied with the final product.There some spots where burnt marks can be seen due to misjudging the path of the laser but I was able to avoid burnt marks on most of the edges. One of the panels also seems to be slightly loose but adjusting the orientation of the piece helps with making sure the box is able to stay together.  I could probably increase the value of the kerf very slightly to fix this problem but I would be using more wood to fix something that is barely noticeable.

Cost Analysis:

OEDK Plywood: $5

Cost of Labor: $15/hr * 3 hours= $45

Assuming power usage is 100 W, laser cutter was running for an hour, and the cost of electricity $0.138 per kilowatt hour: 100 W * 3600 seconds = 360 kilowatt hours, 360 Kwhr * $0.138/Kwhr = $49.68

Estimated total cost: $99.68