Although most of my novice experiments in 3D-printing have been just that, experiments intended to familiarize myself with the technology and its benefits and limitations, I have already had the opportunity to design and print something actually useful. Like most refrigerators, mine has storage areas on the door where items are secured by a removable or adjustable rail, keeping the mustard from flying when you yank the door open. These rails are hollow aluminum sections that accept plastic friction-fitted end caps, which in turn have hooks that engage slots on the door. One of the hooks broke off and naturally fell inside the door, so fixing it with glue was out of the question.

Original right-hand end cap with missing hook, next to intact left-hand end cap

I've been playing with a 3d printer lately, specifically a Solidoodle machine that deposits ABS plastic filament. As part of a larger project I've been designing various mechanical parts, challenging myself to do without support structures and keeping manual finishing steps to a minimum. One of the things I've tried to make is an entirely printed, functional screw thread, for both male and female parts. The result is the nut and bolt combination documented here.

As for the larger project, I'll publish more about that here soon, so keep visiting!

Datasheets for electronic components frequently present maximum ratings and other such specifications in the form of lists where a label, “Operating Temperature Range” for example, is separated from a value, say “-55 to 125 C”, by a dot leader, or row of dots intended to make it obvious which value belongs to which label. Maxim Integrated does this (page two), as does Microchip (page three), among many others. Here's a way to implement it in LaTeX.

Working in open plan offices and other noisy environments has made it obvious to me that I (probably this is true for everybody else, too) can't do my best work without a certain amount of privacy. In fact, “isolation” would not be too a strong a word to describe the most productive environment for me. When my various workplaces fall short of the monastic austerity and complete solitude I imagine to be ideal, which is always, noise cancelling headphones have been an enormous help. I'm using a pair of Audio-Technica ATH-ANC1 at the moment and am very pleased with them, although their on-ear design may be physically uncomfortable for some. Of course, noise cancellation is far from perfect and voices still come through, but filling the headphones with some kind of audio signal helps make up the difference. Music is often too distracting on its own, but I have a few favorite audio loops that are just enough to mask off the world without wearing on my concentration themselves:

• SimplyNoise is a website with white, pink, and brown noise generators, any of which can be amplitude modulated by a slowly varying sinusoid. I suspect the oscillation prevents my mind from getting too good at filtering the noise out and picking up voices again.
• RainyMood.com offers a recording of a rainstorm with occasional thunder. This audio signal is certainly more structured than the other noise sources I use, but the sound of rain is so natural that it's not usually able to break my concentration.
• My absolute favorite, though, has to be this 24-hour long (!) YouTube video of the ambient engine noise heard on the Enterprise from Star Trek: The Next Generation. I grew up with ST:TNG, and I have to admit there's something very comforting about getting some work done with this particular soundtrack!

For more on the relationship between sensory stimulation and workplace productivity, I recommend Susan Cain's Quiet: The Power of Introverts in a World That Can't Stop Talking, which, among other influences, has lately given teeth to my desire for a quiet and focused workplace.

I believe strongly in publishing negative results, so I've written an account of an old project (December 2006), in which I tried and failed to build a solder fume extracting and filtering machine and learned some useful lessons along the way.