In this homework, we were required to design (with the context of the laser cutter as a manufacturing device in mind) a 4″ x 4″ x 4″ snap-fit box with rastered images and text on several sides.

To begin this assignment, I used https://makeabox.io/ to create my box design. One of the most important aspects of using this design tool successfully was to measure the size of the kerf produced by the laser cutter, and insert that measurement into the design parameters. To measure this, I cut out several small squares on a scrap piece of wood and measured the resulting kerf size. Once this was done, my box design was automatically downloaded and generated.

I then opened this file in Illustrator and moved some of the shapes around. To make more efficient use of material, I changed the layout of the laser cut path from the above to the following. This would ultimately result in less ‘wasted’ material.

Once this was done, I grouped the many individual lines of each square into single lines (single groups). I also added some text on one side (name, class, class session, date) and an image of my college crest (Baker).

I also had to edit the stroke of the parts of the file that were intended to be rastered on the laser cutter as opposed to cut.

Once this was done, I emailed the file to myself, opened it on the laser cutter computer, and inserted the design into the template. I followed the quick start guide and changed the settings as required for my material and then let the cutting begin. Specifically, I set the laser cutter to run at 5% speed and 100% power.

Following the first pass, there was clearly a moderately deep cut on the top of the material, but no indication of the laser breaking through on the back of the material. The rastered images and text, however, came out very nicely. Since the sides needed to be cut again, but no more rastering needed to be done, I removed the images and text from the file and reuploaded, such that only the edge cuts would be made.

I then ran the laser cutter again on the same settings. To my surprise, there was still no indication of the laser penetrating the material entirely on the back of the wood. I suspected that it was extremely close to cutting all the way through, so I ran the cut again at 30% speed and 100% power. Still, there was no indication of the laser penetrating all the way through. Following this, I ran the cutter again (using the original settings, 5% speed and 100% power). This time, there were some very light black dashes on the back of the material in the shape of the cutout, meaning that some concentrated light was reaching the back of the material. However, after running the cut 2 more times at this setting (for a total of 5 times at 5% speed, once at 30% speed), the laser had STILL not cut all the way through.

 

At this point, frustrated by the time it was taking (and already having spent far more time in the OEDK that day than I had intended). I decided to push/snap the sides through. In terms of removing the sides, this worked okay. Interestingly, some worked better than others. That is, the strength of the cut was clearly not uniform across the entire job, as some popped out easily with close to no strain, while one had to essentially be cut out with an exacto knife. While the shapes popped out, my frustrated mind had failed to consider the fact that there would not be the required kerf all the way through, as the laser had not penetrated the entire way through. As such, the sides were VERY difficult to connect, as the remaining thin layer of wood had to essentially be chipped away by bashing the sides together with a mallet.

Although the box was quite chipped on the inside as a result of my method of removal from the waste material, the outside actually turned out quite well. I’m unsure as to what exactly happened with the 6th side (which did not fit into place once all other 5 sides were assembled) however the final result at least at least looks quite nice from this angle. 🙂

 

COSTS:

Material:

• Wood:
  • 14″ x 8″ x 1/8″ plywood
  • $6.49 for 30″ x 12″ x 1/8″ plywood
  • Cost: (8 x 14) / (30 x 12) x $6.49 = $2.02
• Time:
  • Design:
    • Time spent: 2 hours
    • Hourly: $20.00
    • Cost: $40.00
  • Use of Laser Cutter:
    • Time spent: 2 hours
    • Cost of machine Hourly: $12.73
    • Labor Hourly: $20.00
    • Cost: $65.46

Total Cost = $2.02 + $40 + $65.46 = $107.48