Most kids make tables, chairs, or boxes for their woodshop class. Instead of that, New Zealander Luke Hamilton decided that for his senior class project, he’d prefer to design and CNC a subwoofer enclosure for his car’s stereo system. Feeling that most car subs were too flashy and tacky for his taste, he was inspired to make something sleek, practical, and totally custom.
In order to achieve the curved design of the enclosure, he used Sketchup to create a model which he then sliced into flat layers. Underneath the main cavity is another empty area. Hamilton explains, “The port allows air to flow in and out as the subwoofer is playing. From the research I did the channel the air flows down should be a smooth as possible, plus where it exits it should be flared. As the air is flowing so fast any sharp edges will make unwanted noise. You can do a bunch of calculations to get this all right but I was just sticking to basic principles. Thankfully there was virtually zero port noise.”
Once the model was set, he exported these individual pieces — about 60 of them — and set the parameters (how deep, how fast, and at what speed the spindle would work) using a program called Cambam.
Hamilton had never used a CNC machine and had to learn the basics. He used a Craftsman 900ST, which he says “had some issues constantly crashing mid-run, and it seemed that the hard drive was being affected due to the vibration.” Thankfully he was still able to cut the pieces he needed from 18mm MDF (and probably learned some bonus CNC problem-solving skills from that cranky machine). He sanded the fresh cuts and then glued the pieces together, first into three smaller sections, and then gluing these all together.
In order to perfectly align the pieces, he made a simple jig which he covered with masking tape to shield it from the glue. Next he used a router to round out the edges of the front and rear panels and sanded off the excess glue.
Although he decided to paint the MDF, Hamilton says that the paint job has gotten scratched up from being in his trunk. “After using it for a month or so, I’m very much considering sanding it back to bare MDF as it shows off the way it was built, and bumps and scratches won’t really matter anymore.” If he were to paint MDF again though, Hamilton says Reddit user swolebrah advised that since MDF is “very thirsty,” it’s more efficient to thin down glue with water, brush it on, then sand and paint on top of that instead of blowing through can after can of primer.
Once it was painted and ready to go, Hamilton installed the sub and secured the enclosure to his trunk with velcro strips. Nice job, Luke! We hope you got full marks.
What was the most exciting thing you made in high school shop class? Let us know in the comments below.