I was excited for this project; while I’ve laser cut a lot of things that were exclusively 2D or were only 3D because I was using parallel plate construction, I’ve never laser cut a structure that assembles itself into 3D without any other parts. Building a box may have seemed simple at first, but working with the laser cutter settings made the project much more challenging than I anticipated.
File Preparation
I decided to just make a simple box, which I planned to put my name and college crest on. However, during the crate tour in class yesterday, I saw someone (sorry I forget who) that etched a QR code on the back of their crate that linked to their blog post. I thought this was a great idea, so I made a placeholder blog post, grabbed the link, and generated a QR code of it with an online QR code generator.
Now that I knew what I wanted to put on the box, it was time to make the shapefile for the box. I used makercase.com in order to generate the shapefile. My settings that I used for the final cut are listed below:
I also used a kerf compensation of 0.0015″. This generated the shapefile you see on the right; I downloaded the .svg file and put it into Illustrator. From here, I removed the “front”, “back”, “top”, etc. notation, changed the edge line stroke to 0.001″, and imported my text, college crest, and QR code. This is what the Illustrator window looked like:
From here, I just sent the Illustrator file over to the laser cutting computer and started setting up the cut. This is where the first problem arose; the laser cutter wouldn’t recognize a combined vector and raster cut, and would only recognize one at a time. I made the decision to drop my shapefile at a specific origin, cut the entire image in raster (including the vector cut lines), then go back after with an edited file that didn’t include the logos and cut it in vector. This worked pretty well the first time, although I did have to use two passes to cut out the entire box.
Laser Cutting
The settings I used for raster were 50 power, 100 speed, 600 resolution, and for vector were 100 power, 20 speed, and 10 frequency. Here’s an image of it cutting the first raster, and then it doing the vector pass:
This is where I can talk about the two mistakes I made when cutting the box. On my first attempt, everything looked like it came out perfect; the boxes separated from the wood cleanly and the finger joints looked great. However, when putting it together, I realized that the finger joints looked a bit too short. I went back and looked at my settings; I had the wood thickness at 1/8″, or 0.125″. I pulled out some calipers and measured the wood to be 0.2″, which is when I remembered the OEDK stocks 5mm wood, not 1/8″. So I had to go back and redo it with updated settings. This time, everything looked good from the start, but separating the pieces from the sheet was extremely difficult. I had to spend about an hour cutting out the “almost there” finger joints with the ultrasonic knife (awesome tool!) until I could safely separate everything. 
I realize now this had to do with my “down-focusing” technique that I used to some success earlier, but made a small mistake with on my second attempt. When the laser cutter auto-focuses, it focuses to the top of the material, not the center. I cut like this on my first attempt at the box, then on the second pass, “nudged” the focus 0.1″ down, so it would be in the center of the material. This worked great and it easily incinerated the small remaining bit of the material and the boxes popped free. But, on my second attempt, I did this focus nudging on both passes, not just the second. This caused the first pass to be a bit weaker than it was the first time, so it didn’t cut through all the way when the second pass had more to cut through. I learned now that the focus nudging technique works well, but only if you’re using multiple passes and top-focus on the first one.
Post Processing
Lastly, I threw some more of the Rust-Oleum “Barn Red” stain that I used on my crate onto the box to match the Baker colors. I really liked how this came out, but it made me regret not using a more powerful setting on the raster pass, because the text, crest, and QR code now only show up in really good lighting. The 50 power 100 speed setting looks amazing when you aren’t using a dark stain, but I would have gone with more power if I knew how little it would show up. Here are a few photos of the final box:
Reflection
I think the main things I would change if I did this again were already mentioned, like fixing the focus when using two passes and using more power on the raster engraving in order to compensate for the stain. However, I absolutely love my final result and definitely learned that Barn Red stain and Baker-themed things get along extremely well. I can’t wait to laser cut more things in this style in the future!
Cost Analysis
- Labor: 4 hours at ~$20 an hour = $80
- Wood: 1x 18×24″ board at ~$5 a board (Lowes)= $5
- Stain: 1 can at ~$14 a can (Ace Hardware) = $14
- Tools are a shared resource = $0
Overall, this project cost about $99, including my approximate hourly wage and all consumable expenses.
