When manufacturing processes halt due to machine misalignment, companies risk significant losses. However, these costs can be avoided via preventative maintenance. By Eddy Lek, Product Marketing Manager, and Anthony Lur, Product Marketing Specialist at FARO Technologies.

Well-maintained machines are the foundation of manufacturing processes. Adopting a preventative maintenance approach not only helps minimise the likelihood of equipment failure or downtime, but helps ensure products meet quality benchmarks. Moreover, machine alignment significantly increases the lifespan of tools.

Companies used to rely on traditional alignment methods involving tools such as machinist levels, piano or tight wires, optics and lasers. These tools frequently worked well but often served only one dedicated function. Calibration and alignment would typically take days or even weeks, involving multiple instruments, which translated to higher costs and more time setting up each step. Naturally, companies sought out better, faster methods.

In the early 1990s, the use of laser trackers became widespread. Compared to traditional methods, the laser tracker is a powerful, user-friendly device that can perform multiple measurement tasks in a much shorter time. Laser trackers combine the capabilities of several traditional tools, and can capture data points in a 3D space, providing users with higher precision and versatility in data usage.

  1. Machining centres

On horizontal/vertical machines, bridge, column, or gantry-type machines, the laser tracker can be used to check for surface level, straightness, flatness and squareness. The target is placed on the machine bed to capture measurements, and users can either make adjustments in real time, or obtain a complete set of points before adjusting the machine bed.

For tool alignment, the target can be placed in the spindle, chuck, or quill. Measurements can also be obtained by placing the target on a pin nest mounted directly into the drill. Alternatively, it can also be placed in a ‘puck’ or drift nest, which can be glued on to a moving bed. As the target sits on its respective locations, 3D data points are collected while the machine travels through a range of movements. Apart from checking the machine bed, the tracker can be used to check for plumb, level, or ensure parallelism in the rails. Conducting 3D volumetric accuracy checks and re-mapping the machine are also possible.

The same checks of levelling, squareness, alignment, and 3D volumetric accuracy checks can be made on boring mills, jig borers, gantry drills, routers and lathes. For lathes in particular, laser trackers can perform turning centre alignment by tracking a target that is affixed on to the headstock with a drift nest. Much like with machine beds, data points are collected as the headstock turns, moving incrementally towards the tailstock in a circular fashion. Adjustments are then made to align the tailstock with the headstock.

  1. Machinery

With presses, laser trackers are useful for checking perpendicularity and parallelism of posts, as well as platen parallelism. The ends of each pole on each side of the planes are measured and compared to ensure it lines up square (between pole and plane) and parallel (between planes) respectively. Any deviation can be corrected based on the readings acquired.

Laser trackers are also effective at conducting shaft alignment checks in roller mill machinery. Shafts need to be in proper alignment and orientation to function well, and the laser tracker allows such checks to be performed easily on rolls. Real-time adjustments can be made as measurements are taken. Data points at both ends of a shaft are acquired by placing the target on the cylinder. The information collected by the software allows users to identify the movement required to put each roll back into alignment.

  1. Other equipment

In calibration of robots, the target is ‘held’ by the robot while measurements are taken. The laser tracker dynamically tracks the target as the robot moves through its programed path. By analysing the data points, a user can tell how much the robot has deviated from its nominal path, thereby directing him on remapping, calibration, or error compensation actions that will allow the robot to move properly through its range of motions.

In the assembly of power generation equipment like drivelines, the laser tracker can ensure that components are lined up correctly, according to design. The laser tracker is mounted with a magnet to hang off the side of a machine, so that it has a direct line of sight to all the features of interest. In this manner, the laser tracker can take measurements of the driveline while it remains on the machine tool. As checks are being made right on the shop floor, adjustments can be made without taking the set-up apart, which saves time and eliminates the need for rework.

Evidently, the laser tracker is an effective complement for the practice of preventative maintenance, which reduces downtime, enables cost-savings, and also improves the quality of output. A robust tool that can be deployed anywhere on the shop-floor, the laser tracker’s multiple functions can replace a variety of hand tools. Companies expanding their capabilities to include in-house machine alignment now have the laser tracker as an option.

www.faro.com