Fab Academy at AS220 Labs

November 25, 2009 11:47 AM

Make something (anything) big

by Makeda Stephenson

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.

Photobucket

Return to front

Older articles