I designed a very simple set of modular cube-type shelves that can be stacked side by side or on top of each other to form a larger shelf or bookcase. Inner shelves will be attached with metal hardware, as will the back and sides of the shelf

It was going to be a skateboard...
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Our last module was on computer numerical machining and the assignment was to make something big on the ShopBot.

A few years ago, I made these star-shaped boxes on the laser cutter with thin (1/8″) plywood. For this assignment, I thought I’d scale up the design and make a few for my mom.

In my original design I used tension fits to pressfit it together, which was fine on a small scale. As I contemplated the modifications I’d have to make to scale it up, I realized that I’d need to actually model it in 3D and carve angled edges to accommodate the angled corners of a star shape. I did the 3D modeling assignment, but I did it in SketchUp because I didn’t have the time to become sufficiently competent in Blender.

Eliot, (one of the student in my class) hadn’t completed the 3D assignment so he made a model in Blender and carved it on the ShopBot. I figured I could do the same with my project and become proficient (sortof at least) in a more conventional 3D modeling environment while completing my CNC machining assignment.

Not so fast.

It was the middle of the first week before I reached a solid decision. (I was still working on hacking parts for our PCB Fab assignment from the previous module…aahhh.) After seeing what Eliot was doing and playing around a little bit I decided that this could only be so hard. Thats true of course, but “only so hard” turned out to be about 4 times more confusing than I had thought.

We played around with the program, completely ignoring the “extrude” tool for the first couple of days in favor of an agonizingly complex and excruciatingly inefficient combination of {select-push/pull-cut-delete-create face-face is warped-cut again-delete extra faces and edges-it looks good-no its skewed-cut-my brain is now crashing} rinse and repeat as many times as needed… method.

By the time we found our good friend “extrude” again, it was Friday. I planned to work on it over the weekend. Not surprisingly by Monday, one crazy weekend and two non-supportive computers later, there was no virtual star-shelf to be ushered into the analog world.

Shawn agreed to come up to the Boston lab to help me with the ShopBot on Tuesday. Switching to crisis mode I decided to make a sign for our lab instead.

When Shawn arrived in Boston I had an Inkscape file ready to cut.

I designed some shelves and cut them out on a Shopbot. While working, all pieces have to be secured to the bed of the machine (or to each other) because the tool is so powerful that the router could send a loose piece flying and seriously hurt someone.

I screwed my 4' x 8' sheet of MDO (medium density overlaid plywood) to the bed of the machine, and we programmed it to cut tabs between some of the parts so they would remain attached to each other. The finished sheet resembled a plastic toy whose tabbed pieces would be broken apart and snap assembled.

Here are some of the shelves after being cut on the Shopbot, and broken apart with a jigsaw.

Thanks to the Avineris for letting me borrow a palm sander. I used it to sand the tabs off the edges of the shelves.

I primed, painted, and installed the shelves in a corner.

I have more shelf pieces cut, but I haven't yet decided where to install them. Photos of my pieces on the Shopbot at Keeseh Studios will be posted after the holiday.