Background

During my laser cutter training, we were able to do a kerf test as practice. We used the method outlined in the Google Doc, drawing out a box and making 10 separate pieces inside on Illustrator. After doing the cut, we pushed the pieces to one side and measured the gap with a caliper. After diving that value by 10, we got a value of 0.004 inches.

Designing the Box

I started my box a couple days later, so Milene and I wanted to redo the kerf test just in case. Before even touching the laser cutter, I designed my box on en.makercase.com. I adjusted the material thickness to be a custom thickness of 0.196 inches, because I used a caliper to measure the exact thickness of the board provided. For the finger joints, I used a tab size of 0.588″.

Box settings I inputted into the website

Making a Test Cut

Next, I decided to make a test cut on my board just to make sure that the power and speed I chose would work well for all my cuts. I first put down weights on my board to ensure that it was flat. Then, I made a 2″ by 2″ square in the upper left corner on Illustrator. The settings I chose were what was suggested on the wall: 4 speed, 100 power, and 10 frequency. The test cut turned out great, so I kept these settings for the rest of my cuts.

        

Left: placing weights on the board; middle: settings of test cut; right: test cut

Kerf Test

As I mentioned before, I wanted to redo the kerf test because the first time we did it was a couple days ago and there could be a possibility that the measurements could change. I also wanted the opportunity to do it on my own. I made my own rectangle with 10 pieces on Illustrator, as shown below.

Rectangle I drew in Illustrator for kerf test

The first time we cut it, the laser cutter cut out the outer rectangle first, then the lines inside. This was not ideal because cutting out the outer piece made it “fall through” the board, which made cutting the lines inside less accurate. I stopped the machine. I talked to Luke for help, and he mentioned that the laser cutter cuts in the order of what you draw first. So, I deleted the outer box and put it back in place so that it would be the final cut the laser cutter did.

Left: cutting the outer rectangle first; right: cutting the inside cuts first

After making the cuts, I pushed the inner rectangles to one side and measured the gap. When I used the caliper to measure the gap, I got a value of 0.111 inches. Divided by 10, I got a value of 0.0111 inches. I noticed that this value was very different from the first time we did the kerf test in training. I was a little worried that my measurements were inaccurate. Just as I was thinking about what could have gone wrong, Lulu and Tony came in. I didn’t realize that they had signed up for a time slot, so I was politely kicked out. Before I left, I asked what kerf value they got, and they said 0.004 inches. She said it worked for her, so I got even more worried that my measurements were wrong. I left the room somewhat distressed.

Pushing the rectangles to one side to measure the gap

Cutting Out the Sides

As I was leaving the OEDK, though, I made a plan: since I also got 0.004 inches the first time I did the kerf test during training, I would make two sides of the box using that value as the kerf. If the pieces fit together, I would continue printing out the rest of the box with this kerf value. If the pieces did not fit together, I would make another two sides of the box using the kerf that I had just calculated on my own (0.0111 inches) and see if that worked better.

I came back an hour later (this time making sure to use the sign up sheet), and decided to test out my strategy. I input 0.004 inches on the website and downloaded the .SVG file. Since I only wanted two sides to test it out, I deleted the four other sides on Illustrator. After cutting, the two pieces fit together snugly. I decided that there was no more testing to be done and I could cut out the remaining four sides.

Testing if 2 sides fit together

Engraving

I remembered to add the Jones crest as well as my name on 2 separate sides. For the engraving settings, I used the one suggested on the wall.

         

Left: settings used for engraving; right: inserting my name and college crest on Illustrator

As I was watching this job print, I noticed near the end that the laser cutting cut through the “S” of my name when it was meant to be engraved. I immediately pressed stop. I went back to Illustrator and noticed that the stroke thickness was wrong so the laser cutter interpreted it as a vector cut rather than just engraving.

Mistake: the laser cutter cut through the “S” of my name

After adjusting the settings correctly, the sides of my box were done!

Finished Product!

The sides of the box were able to snap into place quite easily. Below are images of my box from different angles.

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Reflections

While this was one of the simpler projects we’ve had so far, I learned a lot about the importance of the testing process to conserve time and resources. I also have never used a laser cutter better, so I enjoyed familiarizing myself with the tools and software. I know it’ll definitely become of great use for our midterm project!

Cost Estimate:

• $12 per hour x 2 hours = $24
• Plywood sheet = $10 (Amazon)
• TOTAL = $34