Getting paid to do what you enjoy is a special treat. A machinist and fabricator by trade — hobbyist hacker by design — [spdltd] was commissioned to build a mechanical art installation with a steampunk twist. Having complete creative control, he convinced his client to let him make something useful: a giant electro-mechanical clock.
Pieced together from copper, brass, steel, aluminium, and stainless steel, this outlandish design uses an Arduino Yun — a combination Linux and Arduino microcontroller board — to control the stepper motor and query the internet for the local time. Upon boot, the clock auto-calibrates by rotating the clock face until a sensor detects an extra peg and uses that to zero on twelve o’clock; the Yun then grabs the local time over the WiFi and sends the stepper motor a-spinning ’till the correct time is displayed.
At first glance, you may find it hard to get an accurate read of what time it is, but an accent piece’s pegs denote the quarter hour once it lines up with the notch above each hour. At least this one doesn’t require you to match colours or do much math to check the time.
Unwilling to permanently modify his DSLR camera lens and dissatisfied with after-market lens gearing solutions, [Jaymis Loveday] learned enough OpenSCAD to generate gears from 50mm to 100mm in diameter in 0.5mm increments for a snug friction fit. Teamed up with commercially available focus pulling equipment, these lens gears should really help [Jaymis] get professional results from consumer lenses. 
