It was always a relief, back in the day, when I managed to hire a foundation contractor who truly respected layout. I can recall just a few too many times when I had to adjust the building dimensions to fit an out-of-whack foundation. Although precise methods for layout have existed for thousands of years, not everyone seems to accord them equal value. Ponying up, say, $40,000 for a transit may strike you as over the top, but Hunzinger Construction of Brookfield, Wis., did just that. Of course, this was no ordinary transit — it isn’t even called a transit. It’s a “Total Robotic Station.” And Hunzinger is a commercial contractor specializing in industrial-size jobs. Says project superintendent Brad Caspari, “The first time I set up the unit on the corners for a 290-by-110-foot building, I was only ‘off’ the surveyor’s points by 1/16 inch. Try that with string and a tape measure.”
The tool requires only one person to operate; it relies on a tripod-mounted head unit that uses radio signals to track a hand-held computer-equipped marking rod. The robotics come into play as the head unit turns and tilts to follow the rod around the job site. Once it locks on, the head bounces a laser beam off a prism at the top of the rod to...
to read the full article.