My middle son shares my passion for all things technical. He begged for a LEGO Mindstorms robot when he was 7, and though we held out until he was 8, it’s been one of his favorite and most-used possessions ever since. Buying him birthday presents is always fun, particularly when I get to play with his new “toys”. Two years ago he became the only kid on the block with his own Van de Graaf generator. This year, we’d been discussing 3D printers and how cool the technology is. I figured that in a few years they would be commonplace enough to buy one. Well, it turns out that the prices have dropped precipitously as a number of 3D printer manufacturers have entered the market. My son turned twelve a week ago, and a 3D printer seemed like the perfect present.