For our fifth homework assignment, we were tasked with making a box by using the laser cutter. In previous years, I had briefly used the laser cutter to make a box and to etch an image. However, since a lot of time had passed since then, I found the laser cutting lesson to be quite helpful.
I’ve always been intrigued by the laser cut hinges in the laser cutting room and I was curious to try one for myself. I decided that I wanted to laser cut a box with a hinged lid. I scrolled through Pinterest and Instructables to see if I could find any boxes that I liked and had the hinge I was looking for. When I found one I liked, I decided to pursue it.
A hinged box I liked.
Through the site where I found the box, I was able to customize the exact dimensions and features of the box (i.e. the settings for the hinge, the finger joints, the thickness of the material used, etc). I input my desired values and proceeded to download the file.
Once I downloaded the file, I cut the parts in cardboard to understand how they fit together and to ensure that the Illustrator file was correct. From my initial assembly, the box looked good so I moved onto cutting the parts in wood.
The assembled cardboard box.
The box parts cut into cardboard.
Before I cut all the parts in wood, I ran a quick test run on the wood sheet I had selected to check that I was cutting with the right settings. I did test cuts with varying speeds (4,5, and 6) and a frequency of 10 and power of 100. I found the best speed to be 4. Now that I had the right settings, I cut the remaining parts of the box.
I laid out all the parts and tried joining them. The fit between the finger joints was a little tight, which made the assembly a little difficult. Yet, in the end, I liked the tight fit because because it meant there were no gaps and no glue was needed to keep the box assembled.
The laid out wood cuts.
The first big challenge I faced was the breaking of the hinge. I had feared this would happen because I knew it was the weakest part of the box. I also think I forced the wood to stretch out too much and too quickly. Nevertheless, when I had assembled the box in cardboard, the hinge hadn’t broken. I realized the cardboard hinge probably didn’t break because cardboard is a more giving material than wood. I had to recut the same piece again.
The broken hinge.
When the piece was recut, I reassembled the box. The lid didn’t go down all the way because the hinge wasn’t stretched out to its maximum. I could’ve made the lid heavier or added a lock to help the lid go down, but I chose to stretch out the hinge first and take it from there. Since I had already broken the piece the first time, I was hesitant to suddenly stretch the hinge. For that reason, throughout the day, I slowly lowered the lid a few centimeters. The lid didn’t pop back up at the different heights because it was held down by the sides of the lids. With time, I was able to completely lower the lid so that It touched the side of the box.
The assembled wooden box when the hinge still wasn’t stretch out.
The wood box with the stretch out hinge next to my cardboard prototype.
Two things that I later noticed about my box was that the front of the lid didn’t cover the front side piece (it was aligned with it) and there was a lot of space between the finger joints. I decided to adjust the drawings and recut the box to address these issues.
To fix the misalignment between the finger joints, I modified each finger on Illustrator by making them longer. I also tried to extend the length of the sides of the lid. I then cut the parts in wood. This was the beginning of an extremely frustrating work session. Although I was able to fix the joints almost immediately, I struggled with the extension of the lid.
My first mistake was that I extended the lid’s side piece on the wrong end. I lengthened the back of the side piece instead of the front end. After making that fix in the drawing, I recut the piece and realized that I hadn’t lengthened the long hinged piece (which includes the top and the back pieces). I had to recut the piece, which took two runs because the laser cutter didn’t cut half of one side on the first run.
The half cut lid piece.
Another challenge I faced was that I had to readjust the front piece of the lid because it wasn’t fitting correctly with the side lid pieces.
An example of the mismatch between the front and side pieces of the lid.
I spent a significant amount of time continuing to adjust the drawing and then cutting it, but I was unable to find the right design. Additionally, throughout the process of reassembling and disassembling the parts, I started to break away parts of the wood.
Parts of the wood broken off of the finger joints.
Because of my frustration with the misalignments and the amount of time I had spent, I decided that I couldn’t invest more time on the fix and chose to leave the lid aligned with the front piece. Unfortunately, it’s not the result I would’ve liked, but I think the box still looks decent enough.
One positive thing that I discovered from my last set of iterations is that the hinged piece easily stretch out. With the help of Julianna, we believe that this happened because the hinge was cut along the grain of wood rather than against it.
Here is the final outcome of my box:
Cost Estimate
Labor
- I worked for 5 hours, assuming a rate of $15/hour = $75
Materials
- Plywood: ¼ in. x 4 ft. x 8 ft. sheet sold by Home Depot for $28.82. I used approximately ½ of that amount, so $28.82/2= $14.41
Machining
- To use a laser cutter at a fabrication lab outside of Rice, I would have to pay at least $50 (the price of the “Tinkerer”, the cheapest membership which includes full access to tools at TXRX Labs)
Total cost: $75 + $14.41 + $50 = $139.41
