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George LeGrand

CMSC

How Often Do You Need a Machine Alignment Inspection?

Published: Wednesday, February 15, 2017 - 10:52

One of the questions our customers ask most frequently is, “How often do I need to have my machine inspected for alignment?” Unfortunately, there isn’t a simple answer. There are a number of factors that can affect the alignment of equipment and these should be taken into consideration when creating a machine alignment inspection plan for a facility. I will discuss the top three factors that can determine the need for alignment inspections, and the reasons why there are no set rules that can be applied.

Type of machine

Alignment inspection intervals can vary from machine to machine. For a typical paper machine that runs continually at standard operating speeds, alignment condition inspections should occur every 12 to 18 months, with sampling inspections conducted in each of the major sections: wet end, press, dryers, calender, and reel.

However, in today’s competitive environment, the majority of paper manufacturers are running up against their speed thresholds to maximize production. This practice significantly shortens the alignment inspection intervals—often from 6 to 9 months.

Printing presses and winders typically run at much faster speeds and require a greater degree of accuracy to ensure maximum productivity. Because of this, these machines should be inspected more frequently.


Image 1: OASIS metrology engineer uses a Leica Absolute Tracker AT960 laser tracker to inspect the wallboard process line.

Corrugators and some laminators typically have “looser” optimal operating tolerances, allowing them to have a greater interval of time between inspections.

Age of the machine

A machine’s age has a direct effect on how often an alignment inspection should be performed. In the case of a newly installed line, one may think that the intervals between alignment inspections could be much longer. However, the opposite is actually true. Alignment inspections are critical during initial operation, with the largest factor being foundation settling. When installing a piece of production equipment on a new foundation, the foundation may not settle equally under the weight of the machine causing the component movement. Shorter intervals between inspections can capture that movement and allow you to make necessary adjustments. Shorter intervals between inspections also allow you to monitor thermal expansion, operating vibration, frame movement, and mounting hardware issues.

Older machines are prone to worn bolts, elongated mount holes, and the tendency for increased vibration from unbalanced components. These issues all promote component movement. Shorter intervals between alignment inspections are needed to map the rate of alignment degradation.

Maintenance practices

Typical predictive/preventive maintenance plans include vibration monitoring, gear clearance inspections, component lubrication, and housekeeping. During maintenance downtime, it is sometimes also necessary to reposition components such as rolls, drive components, bearings, and couplings.

If component repositioning activities are accomplished without alignment best practices in place, the overall alignment condition of the machine will degrade much more rapidly. This will require shorter intervals between alignment inspections. Conversely, if alignment best practices are included as part of your maintenance plan, not only will your machine run at optimal performance levels, but the intervals between alignment tune-ups will be longer.

Other factors to consider

Other factors that should be taken into consideration when creating a machine alignment inspection plan include such things as the location of your facility. (Are you located in an earthquake and/or flood zone?) The age and condition of your manufacturing area or building, harsh mill environments, building settlement, and cracked or broken flooring will all have a direct effect on how often your machine should receive alignment inspections. Even the type of product you run can have an effect on when and how often your machine requires an alignment inspection.

In summary, there are no set rules, as the timetable for machine alignment is unique to each facility. Building a strong partnership with alignment service professionals can yield an inspection plan that is best suited for each individual customer based on their machines and processes, product specifications, production requirements, and the preventive maintenance plan.

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About The Author

George LeGrand’s picture

George LeGrand

With almost 20 years at OASIS Alignment Services, George LeGrand has a broad range of experience with all types of industrial manufacturing equipment. As an Optical Engineer, George worked on paper machines, coater/laminators, corrugators, printers and more. He is currently Account Manager for the Southeast Region. For more information on OASIS, visit http://www.oasisalignment.com.