Fixing a useless box

Published on March 8, 2017

By: Wayne Dorrington

For the most part, we’ve been creating decorative objects, printing out some great conversation pieces for visitors – and in the process, several people in the office have now been bitten by the plastic printing bug.

So when Front End Developer Azlan Cuttilan arrived at work one morning to find that a cleaner had accidentally broken his Useless Box – it seemed the perfect opportunity to use the 3D Printer to help repair it. But what is a Useless Box?

I quite like how Think Geek describes it,” explained Azlan. “Ok, so it’s a black box, sort of shiny, with a switch on top. But what does the switch do? Does it launch a nuclear attack? Does it terminate someone you don’t know somewhere in the world? Does it make bacon magically appear? You stare at it over and over, hour after hour, until you can’t take it anymore. You turn it on. And out of the box, a little finger pops out and turns the unit back off. That’s all it does, and the smile on your face is proof it works. Admittedly mine is neither black nor shiny.”

You turn it on. And out of the box, a little finger pops out and turns the unit back off.

So, using the neither-black-nor-shiny part for measurements, I recreated it as a plan in Adobe Illustrator, at 1:1 scale. I used my Vernier Gauge* to get accurate dimensions (as best I could, anyway. To paraphrase Doctor McCoy from Star Trek, “Dammit – I’m a Designer, not an Engineer!”)

Then next step is to create a 3D model we can use to print with – so I used Autodesk 123D, importing in my Adobe Illustrator drawing, and extruding it to the thickness of the box part.

Now, we can use this 3D file to create our 3D print. The last step is to use a program called a Slicer. This takes a 3D model and digitally slices it into… well, slices. It saves all this data as a series of coordinates and numbers, which I then saved onto a memory card and loaded into the 3D printer.

The machine itself is actually more mechanical than digital – it’s more motors and drive belts than computers. All it’s doing is mechanically moving the extrusion head (heating up plastic and squirting it out in thin layers) and building up a 3d shape layer by layer as it does so.

The slicer uses the slicer code file (known as a gcode file) as instructions on where to move its extruder head, when to start squirting and when to move onto the next bit. And that’s pretty much it.

Usually, in my experience, things can still go wrong. Any number of technical issues (sometimes even just having the wrong temperature room) can cause a print to fail. But luckily on this occasion, the part printed out, and it was over to Azlan to install.

With only a very minor bit of fettling, it worked first time! (I think I was more surprised than Azlan about this).  And with the tiny bolts reattached, the Box was saved to once again be absolutely and definitively Useless.

*An extremely accurate measuring tool that I have used precisely twice since I bought it over a year ago.