Your Guide To Laser Shaft Alignment

There are many types of shaft alignment tools on the market such as straight edges, optics, feeler gauges, dial indicators or calipers. Laser shaft alignment however, has become the alignment tool of choice.  

Laser shaft alignment (commonly known as coupling alignment) is the process of aligning two or more rotating shafts in a straight line. This involves looking at both the vertical and horizontal plane to try and ensure they are rotating on a common axis (coaxial).

laser emitter and a laser sensor

How Laser Alignment Works

Laser monitoring systems consist of a laser emitter and a laser sensor. The laser emitter is mounted using a bracket and chain to one shaft and the laser sensor is mounted to the other.

The laser emitter shoots a laser across the shaft to the sensor in a single beam laser set-up. Sometimes both sides will emit a laser and both will simultaneously act as a sensor. In that situation it is known as a dual beam laser.  In either situation, as the laser is being emitted, the shaft is rotated to find the center lines of rotation between the two shafts.

Laser alignment display unit

The laser sensors send the information to a display unit or tablet that displays the alignment. Units may be either offset, have an angular misalignment or both. Once the misalignment has been identified the movable piece of equipment is adjusted vertically and/or horizontally. The goal is to come as close to coaxial, or perfectly aligned, as possible.

The software will take into account allowable tolerances put forth by manufacturers to determine if realignment is necessary. Most laser shaft alignment system perform calculations and display them graphically to help with the alignment process.

Alignment At Your Facility

We perform laser alignment as part of routine maintenance on facilities critical equipment. This way a baseline is established and can help you see alignment changes year over year.

You can also use laser alignment to check recent equipment installs. This is generally done after 3-6 months of operation to ensure the equipment’s operating with designed parameters.

Technicians working on rotating equipment The Importance of Shaft Alignment

Improper shaft alignment is responsible for roughly 50% of all rotating machinery breakdowns. Misalignment causes excessive vibration and puts high loads on seals, packing, couplings and bearings. It can also cause temperature fluctuations due to friction, energy loss and even motor failure.

By properly aligning shafts, you will use less lubricant, lower noise levels, increase equipment life and waste less energy.

Laser Shaft Alignment VS Alternatives

Of all the ways to measure alignment, laser shaft alignments is the fastest, easiest and most accurate way to test equipment. Straight edges, optics, feeler gauges, dial indicators and calipers all fail in comparison. ATE Corp does a great job of describing the benefits of lase shaft alignment:

“Laser beams are free from the laws of gravity, immune to bracket sag and eliminate coupling anomalies. A laser shaft test system can:

  • Rotate to compensate for coupling anomalies
  • Calculate precise values for horizontal and vertical (shimming) corrections
  • Measure more than two machines, all in the same measurement 

Some laser systems even measure flatness, straightness, and parallelism.”

Need Help?

Call the Reliability Experts at RasMech at 1-800-237-3141.