Custom pneumatic cylinders fix this monitor arm

Few consumer PCs are built to last. Most office machines are almost certain to die if they collect too much dust, and the average laptop can barely handle a few drops of latte and muffin crumbs before giving up the ghost. Putting such a machine in a workshop, especially a metal workshop, is practically a death sentence.

And yet computers are so useful in the workshop that (Lucas) of “Cranktown City” built this snazzy industrial-grade monitor arm. Its design will look familiar to anyone with a boom-arm microphone or desk lamp, although his homemade parallelogram arm is much sturdier thanks to the weight of the monitor and the sheet metal case it supports. All of that weight exceeded the capability of the springs (Lucas) had available, which led to the most interesting aspect of the design – a pair of pneumatic locks. These were turned from a piece of aluminum rod and an old flange-head bolt; when air pressure is applied, the bolt is pulled into the cylinder, which locks the arm in place. To make unlocking the arm easier, a pneumatic magnet releases pressure on the system at the push of a button. The video below has a full explanation and demonstration.

While we like the idea, there are a few potential issues with the design. First, it’s not a fail-safe design because pressure is required to keep the arm locked. That means if the air pressure drops, the arm could unlock, allowing gravity to take a toll on your beautiful monitor. Second, there’s a more serious issue that (Lucas) alluded to when he mentioned that he doesn’t want to be in the line of fire of these locks in case something fails and the piston flies out under pressure. This could be fixed with a small design change to keep the piston locked in place in the event of a catastrophic failure.

Issues aside, this was a great build and we’re always amazed by (Lucas)’ intuitive engineering and obvious talent for manufacturing, of which his wall mounted plasma cutter is a perfect example.