FARO
Feature Article for Q2 Topic – Metalworking, Machinery & Assembly
Machine Alignment with Laser Trackers
byMr. Eddy Lek, Product Marketing Manager &Mr. Anthony Lur, Product Marketing Specialist
FARO Technologies
The popular adage –“If it ain’t broke, don’t fix it” – might be a piece of advice that is dished out often, but perhaps
less appropriate if applied in the context of a manufacturing facility. In the world of mass production, machines are
put to repetitive tasks each day to churn out large outputs of identical items. Seeing that production volume is key,
it is vital to ensure that machines are often checked, so thatthe manufacturing process never gets disrupted.
When the manufacturing process is halted due to machine misalignment, companies risk losing a significant amount
of investment in the form of time delay, reduced productivity, and scraps. However, these costs can be avoided if
companies take careful ownership of preventative maintenance, minimizing the likelihood of equipment failure or
downtime.
In fact, by adopting the preventative maintenance approach, quality management departments can also better
ensure thatproducts leaving the facility meet quality benchmarks, as well-maintained machines are the foundation
of manufacturing processes. Besides, machine alignment significantly increases the lifespan of tools, which can be
expensive to replace. For these reasons, companies have found it necessary to perform machine alignment
regularly and efficiently.
Single-use Tools vs. Multi-function Device
In the past, companies used to rely on traditional alignment methods that involved tools such as machinist levels,
piano or tight wires, optics (e.g. bore scopes, theodolites, etc.), and laser.While these tools worked well in most
cases, they often served only single, dedicated function. Using these methods, calibration and alignment would
typically take days or even weeks to complete. It was also common to involve multiple instruments, which
translated to higher costs and more time spent on setting up in each step.
Naturally, companies sought out better and faster ways for machine alignment to be done. In the early nineties,
the use of laser trackers for industrial measurement 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.
This device combines the capabilities of several traditional tools in one, including the ability to: check for plumb,
level, squareness, and parallelism; verify and conduct positional checks of rotary axes and multi-axis heads;
reposition a part on a table without a rotational bed; perform real-time adjustments of machine beds, rails, and
ways; as well as measure bore alignment, coupling, and shaft alignment. More importantly, the laser tracker
captures data points in a three-dimensional (3D) space, which provides users with higher precision and versatility in
data usage.
Basic Mechanics of a Laser Tracker
The laser tracker is a portable coordinate measuring machine (CMM) that is based on 3D
coordinate technology. Fundamentally, these devices provide the benefits of CMMs with the
added versatility of being portable, which allows the user to deploy wherever there is a
need, without having to move their machine. In addition to being less cost-prohibitive than
fixed CMMs, portable CMMs do not require a controlled environment, making it more cost
effective to operate and maintain them.
Designed to handle larger working volumes, laser trackers offer extremely accurate
measurements over long ranges. Put simply, a laser tracker establishes the precise location
of a target in spherical space by measuring two angles and a distance, each time it takes a
measurement. It does so by sending a laser beam to a retro-reflective target, which has to
be held against the object being measured. The return beam re-enters the laser tracker
where the distance to the target can be determined using interferometry or phase shift
analysis.
The FARO® Laser
Tracker Vantage is
25% smaller and 28%
lighter than its
predecessor.
Red Bug Communications Pte Ltd | Public Relations & Marketing Communications | Co. Reg. No. 200922362C
The horizontal and vertical angles to the target probe are determined using precision angular encoders attached to
the mechanical axis of a gimbaled beam steering mechanism. Using the two angle measurements and distance
determined by the laser, the laser tracker can report the coordinate location of the target probe to extremely high
accuracy levels. In addition, the laser tracker can follow or track the target probe as it moves in real time. This
unique feature, coupled with the laser tracker’s ability to internally sampling rate of up to 16,000 times per
second, enables the user to digitize data on complex surfaces ormeasure the location of moving objects.
In fact, laser trackers today have impressive measurement ranges and accuracies that provide users with more
versatility and better results. For instance, the FARO® Laser Tracker Vantage’s radial distance measuring range is
80m, and at that range, it captures data at typical accuracies of up to 39 microns (0.039mm). Weighing just under
18kg, the Vantage offers portability and flexibility on measuring large parts, no matter where production is located
within the plant. Manufacturers can achieve unprecedented speed and efficiency by capturing more with fewer
device moves and shorter routines.
Laser Tracker in Machine Alignment Scenarios
The American Society of Mechanical Engineering 1 established a set of standards for the correct and accepted
methods to check and align machine tools with a laser tracker.Here are some documented scenarios of alignment
being performed on a variety of machining centers, machinery, and other equipment.
1.
Machining Centers
Horizontal/Vertical Machines, Bridge, Column, or Gantry-type Machines
On these machines, the laser tracker can be used to checkforsurface level, straightness,
flatness, andsquareness. The target is placed on the machine bed tocapture measurements,
and users can either make adjustments in real-time, or obtain a complete set of points before
adjusting the machine bed afterwards.
A spherically mounted
retroreflector (SMR)
placed on a drift nest.
For tool alignment, the target can be placed in the spindle,
chuck, or quill of the machining center. Measurements can
also be obtained by placing the target on a pin nest that gets
mounted directly into the drill of the machine. Alternatively, it can also
be placed in a ‘puck’, or a drift nest, which can be glued on to a moving
bed. As the target sits on its respective locations, 3Ddata points are
collected while the machine travels through a range of movements to
check for alignment issues.Apart from checking the machine bed, the laser
tracker can also be used to check for plumb, level, or ensure parallelism in
the rails.Additionally, conducting 3D volumetric accuracy checks and re- Machine beds are checked for
mapping the machine are possible functions.
flatness with the laser tracker.
Boring Mills, Jig Borers, Gantry Drills, Routers, and Lathes
Turning center alignment
of a lathe with the laser
tracker
The same checks of levelling, squareness, alignment, and 3D volumetric accuracy
checks can be made on these machines. For lathes, in particular, laser trackers can
perform turning center alignment by trackinga target that is affixed on to the
headstock with a drift nest. Much like how machine beds are measured, 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
accordingly.
1American
Society of Mechanical Engineering, ASME B5.54-2005 Methods for Performance Evaluation of Computer
Numerically Controlled Machining Centers, 2005.
Red Bug Communications Pte Ltd | Public Relations & Marketing Communications | Co. Reg. No. 200922362C
2.
Machinery
Presses – Platen, Stamping, and Brake Press
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 Checking for
(between pole and plane) and parallel (between planes) respectively. Any perpendicularity and
deviation can be corrected based on the readings acquired.
parallelism of posts in
presses
Rolls
Laser trackers are also effective at conducting shaft alignment checks in roller mill
machinery. Shafts need to be in proper alignment and orientation in order to function
well, and the laser tracker allows such checks to be performed easily on a roll (or series
of rolls). Real-time adjustments can be made as measurements are being taken. Data
points at both ends of a shaftare acquired by placing the target on the cylinder. The
information collected by the software allowsusers to identify the movement that is
required to put each roll back into alignment.
3.
Roll alignment checks to
ensure proper alignment
and orientation.
Other Equipment
Calibration of Robots
In this application, the target is ‘held’ by the robot while
measurements are being taken. The laser tracker dynamically
tracks the target as the robot moves through its programed path. By analyzing
the data points, a user can tell how much the robot has deviated from its
Calibration of robots with
nominal path, thereby directing him on remapping, calibration, or error the laser tracker.
compensationactions that will allow the robot to move properly through its range
of motions.
Drivelines– including Gearboxes, Shafts, and Couplings
In the assembly of power generation equipment like a driveline, 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 onthe machine tool. As checks are being made
right on the shop floor, adjustments can be made without taking the setup 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. It is arobust tool that can be deployed
anywhere on the shop floor, the laser tracker’s multiple functions can suitably
replace a variety of hand tools, making it a worthwhile investment. Companies
expanding their capabilities to include in-house machine alignment now have the
Laser tracker mounted on the
laser tracker as an option apart from traditional methods.
side of a machine to facilitate inline inspection.
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Red Bug Communications Pte Ltd | Public Relations & Marketing Communications | Co. Reg. No. 200922362C
About FARO
FARO is a global technology company that develops and markets computer-aided coordinate measurement devices
and software. Portable equipment from FARO permits high-precision 3D measurement and comparison of parts and
compound structures within production and quality assurance processes. The devices are used for inspecting
components and assemblies, production planning, inventory documentation, as well as for investigation and
reconstruction of accident sites or crime scenes. They are also employed to generate digital scans of historic sites.
With FARO, 3D measurement and documentation needs can be fulfilled confidently. As a pioneer and market leader
in portable computer-aided measurement, FARO consistently applies the latest advances in technology to make its
industry-leading product offerings more accurate, reliable, and easy to use. The focus is on simplifying workflow
with tools that empower customers, thereby dramatically reducing the on-site measuring time and lowering overall
costs.
Worldwide, approximately 15,000 customers are operating more than 30,000 installations of FARO’s systems. The
company’s global headquarters are located in Lake Mary, Florida, with its European head office in Stuttgart,
Germany and its Asia-Pacific head office in Singapore. FARO has branch locations in Japan, China, India, South
Korea, Thailand, Malaysia, Vietnam, Canada, Mexico, United Kingdom, France, Spain, Italy, Poland, and The
Netherlands.
Further information: www.faro.com/sg
General Enquiry
FARO Singapore Pte Ltd
Tel: +65.65111350
Email: asia@faro.com
Editorial Contact— Please do not publish
Ms Kelly Kuan
Tel: +65.62207573
Email: kelly@redbugpr.com
FARO Regional Contacts— Please do not publish
South East Asia:Ms Josephine Lau
Marketing Specialist
Tel: +65.64991616
Email: josephine.lau@faro.com
China: MsRing Pan
Marketing Manager
Tel: +86.21.61917619
Email: ring.pan@faro.com
Japan: MrYoshihiro Iida
Marketing Manager
Tel: +81.561.560125
Email: yoshihiro.iida@faro.com
India: MsAmrita Gokhale
Senior Marketing Specialist
Tel: +91.11.46465644
Email: amrita.gokhale@faro.com
South Korea: Ms Mikyeong (Carrie) Park
Marketing Specialist
Tel: +82.51.6623412
Email: mikyeong.park@faro.com
Red Bug Communications Pte Ltd | Public Relations & Marketing Communications | Co. Reg. No. 200922362C