Laser Cut Box! | ENGI 210: Prototyping and Fabrication

We are back! This week I created a laser cut box. Unfortunately, it was a bit of a struggle, but I was able to persevere and learn a lot from it. I started by getting my piece of plywood and measuring its thickness. I recorded that it was 0.197″. I then calculated my kerf. I started with a test cut to check the settings. I worked with the Epilog Pro and had starting settings of 55s, 35p, 50f and 4 cycles like the TAs suggested. However, my cut didn’t go all the way through, so I adjusted to 45p and had a good cut with no flame. I then cut out the kerf box and measured the gap with a caliper to get 0.0755 which translates to a kerf of 0.00755 when I divide by 10. I pulled all these values into the 2D drawing box generator to create a 4 by 4in box.

I had learned from the lab assistants that covering the plywood in painters tape reduces the charring. I wanted to give this a try so I covered my piece of plywood. I was curious how the engraving would work and asked if I needed to engrave before covering in tape and then vector cutting, however they said it would go right through the tape. I did another test cut to ensure there was no flame with the added tape. All good.

I used the settings 55s, 45p, 50f and 4 cycles as I had successfully tested with my test cut. I used 600 DPI for my engraving. However, the Will Rice emblem has both yellow and red, so I decided to split the engraving by color and make the yellow area 300 DPI.

I cut the sides of my box two at a time. I began removing the tape and assembling the box and noticed some issues. I had some areas where the tape overlapped slightly and that caused the engraving to not be consistent. For example, the bottom of EDES 210 on Side 1 as well as parts of the owl on Side 2 didn’t engrave. The OEDK also had darker stripes that I think was the tape residue. I could wipe it away a little, but then it was slightly lighter. The Will Rice emblem also didn’t turn out as expected. There is a stripe that didn’t engrave properly right above the phoenix’s head, where the tape was overlapping.

I decided that I wasn’t pleased with how my sides turned out. The sides were also a little challenging to put together, so I decided to do it again and adjust the kerf. At first I made the kerf bigger thinking it would make the laser cut less tight and make the slots larger and the tabs smaller. However, after cutting two sides I realized the making the kerf larger assumes that more wood is being cut away and actually makes the tabs larger. I adjusted the kerf once again, lowering it to 0.005. I cut two mores sides and tried to fit them together. Much better!

I decided to abandon the tape. Although there was minimal charring on the first box, I was nervous the engraving wouldn’t come out how I wanted it again. I thought about trying to line the tape up perfectly and tried this at first. However, I had small gaps that I was also nervous would result in noticeable differences in the engraving. I decided to go without it. I cut all sides of my box, with no flame, and assembled them together. The new kerf was much better. Once again, I divided by color and set different DPI values for the Will Rice emblem.

Success! These sides turned out better, with no challenges in the engraving like before. I was pleased with my box! Even though I had some struggles I am happy I worked through them and even added two extra decorative sides. Laser cut box completed 🙂