We help you make sense of laser-based construction tools.
In essence, a laser is just a source of light. The light emitted by a laser diode is different from ordinary light in two important ways: First, each of the billions of photons that make up a laser beam has the exact same wavelength or color. In laser tools, this is usually red light. Almost every other light source we use on this planet emits light in a wide spectrum of colors.
Second, the photons stick together. The beam that comes out of a laser tool stays tightly compacted. If you look at the laser dot on a target 100 feet away from the source, it will be about the same size as it was when it left the tool. Even if it does spread out a bit, the center of the dot is still the center of the beam.
So now you've got a very straight beam of light. What can you do with that on a construction site? Plenty, if you find a way to make the beam level, or split it into two or more beams at 90 degrees from each other, or spin the dot around in a circle to "paint" a level line on the walls. In fact, there are probably a thousand ways to use lasers on site, and, since we've only seen a couple hundred so far, the laser-based tool industry will evolve for quite a while.
I visited several manufacturers to make sense of the laser tools currently on the market. I discussed the tools' construction, function, and future with tool designers and engineers. Here's what I learned.
Optics
Most laser tools sport a single diode, which emits light. That single beam can be split into several beams, bounced off mirrors, refracted through a prism, focused, aimed, and leveled before it comes out of the tool. This manipulation is the science of optics, and it's what laser-technology engineers love even more than stock options.
Companies that make lasers for the construction industry generally use optics to do one of three things with their laser beams: project one or several dots, project lines, or spin a dot like a very fast lighthouse beam to give the impression of a faint line all around the room.
Line projectors and rotators – the second and third options above – sound sort of similar. But a line projector actually spreads a dot out sideways so it looks like a line. One advantage of this is a brighter line, since all the light from the diode is gathered in one section of the circle. Another advantage is that it's a lot cheaper to throw a stationary line than it is to rotate a dot. The downside might be that the guy on the other side of the room can't use the line until someone turns the tool around and points it his way.
Dot Lasers
Construction lasers became affordable when someone stuck a bubble vial onto one of those laser pointers used for slide shows. They soon got more sophisticated, and the stick laser was born – an 18- to 36-inch box-beam level that shoots a laser from one end. Everyone got pretty excited at the prospect of a 300-foot level until they realized that the dot out there was at the mercy of the bubble on the beam. If you moved the beam enough to raise the dot several inches, the bubble wouldn't budge. So, some companies developed more sensitive vials while others suggested working at shorter distances.
Next, engineers found they could split the beam into two dots at right angles to each other, which is useful for layout and squaring frames. Then they found a way to make the laser find level by itself, and still shoot two or three dots at right angles. Pacific Laser Systems (PLS) and Levelite have led the way in developing these multi-beam tools. One PLS tool shoots five beams: up, down, right, left, and straight ahead. Due to optic demands, some of the beams are offset from the others. There's no single common center point from which all the beams originate, so you might need to factor in a correction for certain layouts.
Toolz has developed a five-beam laser in which all the beams have a common origin point, but it's not on the market yet. Watch for the RoboVector to hit the shelves later this summer. And Stabila has a simple new split-beam laser that shoots vertical and horizontal beams at the same time.
