The word LASER is an acronym for Light Amplification by Stimulated Emission of Radiation.
Lasers are devices that amplify light and radiate coherent light beams. Coherent light beams propagate in step with one another. It is this highly directional property of laser beams that make them extremely useful for laser alignment. The types of laser devices that we manufacture, operate at very low power (less than 1 mw), and are safe to use.
Unlike ordinary light sources that radiate light in many wavelengths (colors) and in all directions, lasers radiate a single wavelength, in the same direction, in a straight line. Our laser devices emit visible light, to facilitate setup. Also, unlike interferometers, our lasers can be interrupted without having to be reset.
Detecting the Laser Beam
The laser is detected, or intercepted, by position-sensing detectors (PSDs). The center of energy of the laser spot is detected and converted to an electrical signal proportional to its location on the surface of the target. This signal is converted into a calibrated reading, using a variety of hand-held readouts or computer interfaces for use with our software.
Producing Continuously Rotating Laser Planes
Continuously rotating laser planes are produced by bending a laser beam precisely 90° using an optical device known as a pentaprism. Unlike mirrors, pentaprisms have a unique property where angular changes in the input laser beam do not affect the accuracy of the 90° angle. However, this is only true in one axis, so we add an optical correction to produce our ultra-flat, continuously rotating laser planes that are unmatched in the world! We also check to make sure the Axis of Rotation (AOR) of the pentaprism is concentric with the laser beam. If it is not, this creates what we call a "step error" (also known as a translation error), where one side of the laser beam is "stepped up" relative to the other side. For example, if a surface is aligned with a laser (placed in the middle of the surface) that has a .001" (0.025 mm) step error, then this means that the surface on one side of the laser will be .001" higher/lower (but it will be parallel) than the surface on the other side of the laser.
Our L-743 and L-733 Lasers combine 3 mutually perpendicular laser planes to produce the unparalleled Triple Scan™ lasers.
Making Laser Planes Parallel to References
In general, a laser is used for alignment by making it parallel to reference points or a datum and using a target to measure deviations from those points. For straight-line laser applications, like bore or spindle alignments, 2 points are needed for reference. For continuously rotating laser applications, like machining centers and presses, 3 to 5 reference points are needed, although level to earth is frequently used instead of reference points. "Bucking in" is a term that refers to making lasers parallel to reference points
Once the laser is "bucked in," any point within range of the laser device, typically up to 100 ft (30.5 M), can be measured for deviation in 1 axis for rotating laser applications, 2 axes for bore-type applications or 4 axes for spindle-type applications. One of the principal advantages of geometry lasers is that they provide live alignment data, which means a machine or part may be aligned without moving or changing the laser's setup. In effect, the targets act as a live digital indicator of the alignment. When the target reads zero, the point is aligned and the next point is measured.