In this week’s assignment, we were tasked with using the laser cutter to print a finger-jointed box that could fit together without glue. Since I had some previous experience with the laser cutter as an OEDK Lab Apprentice three years ago, I decided to try to design my own box with multiple compartments for each of the pieces made during the semester. I also the crest of my residential college, Wiess, in the largest compartment and etched the name of myself, the class, the semester, and the date in the box compartment farthest away from the crest of Wiess. Below is a screenshot of my box design/drawing in Adobe Illustrator with its etchings included, which in all took about 2 hours to draw using previous box designs for guidance.
For my first cut, I started with the suggested vector 4-100-10 speed to power to frequency ratio and respective etching ratio of 10-50-50 for my first cut with 48″ by 36″ by ~0.2″ plywood sheeting. However, after watching the printer perform its introductory strokes for about 15 minutes (0.25 hours), I realized that the vector components of my design were not being sufficiently cut all of the way through as they should have been. Shown below is a picture of the initial vector cuts that failed to completely puncture the wood.
After stopping and resetting the machine, I decided to decrease the speed for vector cuts so that a 2-100-10 speed-power-frequency ratio was used instead. Furthermore, since I had not translated the wood when assessing its incomplete vector cuts and with the machine’s home remaining as it had previously been, I simply restarted the print with the only difference being the speed of its vector cuts. This change allowed the second cut of the laser cutter to sufficiently puncture the plywood while the intended etchings were created according to my initial expectations, which took about one hour to complete.
After squeezing the pieces together (in retrospect I would have attempted a simpler design), the extremely-small tolerances each finger joint needed to adhere to required that I used a razor blade to shave a few slivers or wood from some of the joints’ teeth so that the pieces could fit together. This process took around 45 minutes (0.75 hours) to completely fit together and assemble the finished box.
While I ran out of time to post-process the box by applying a finish to the wood or by sanding out its sharper edges, I nevertheless ended up with a compartmentalized box that could hold together on its own as shown below. Furthermore, even though the box did not need additional support to stay together/function, I did eventually decide to tighten some loose corners with clear tape so that I could reliably use the box in the future without fear of its dismantle.
Cost of Project:
- One 36″ by 48″ sheet of 0.2″ plywood costs around $5
- Access to the OEDK for equipment and software needed was free
- Labor cost included 2 hours for the 2D drawing, 1.25 hours for both cuts, and 0.75 hours for assembly, which at an average labor cost of $10 per hour equates to $40 spent on labor
- Therefore, the total cost of the project amounted to around $45
