By Sue Roberts
Almost every part manufactured today must be traceable. From a large part assembled into a
defence product to the smallest of bone screws used
to put people back together, components need to be
An identifier added to a product at the end of
the line might be required to show the who, what,
where, and when of a part’s production to record the batch and/or add a unique code that isn’t
shared by any other part. Or a component might
need an intra-factory identifier used to follow its
progress through production.
Robotic laser marking can be programmed to
place identifiers on thousands of like parts as
they move through a production line or use predefined programs to automatically recognize and
accommodate part differences in a make-to-order
End-of-arm grippers can be programmed to swap
out as needed to present individual parts or trays of
parts to the laser. A robot often can grab and load
small parts easier than human fingers, particularly
when the hand is wearing a glove to avoid transmitting dirt to the parts.
Whatever the identifying need, robotic laser
marking is up to the task for inline production or as
a stand-alone process.
Part ID and Size Flexibility
“One obvious benefit of using laser marking paired
with robotics is the elimination of hard tooling,”
said Dave Girardot, product line manager for the
tools division of North America, Coherent Rofin.
“With a robot you can pick up a part, find it with
vision, and position the part under the laser head.
It gives you an abundance of flexibility on pla-
cing and positioning, and it is easier, quicker, and
cheaper than hard tooling scenarios.”
The flexibility of robotic laser marking allows
programming that will handle a family of parts
that come in various sizes and configurations.
You still need some repetition to make the process
worth the investment, but it is becoming easier and
more cost-effective to use robotic laser marking for
batches that don’t number in the thousands.
Girardot said, “For example, we can look at parts
A1 which are being presented by the robot, pull up
the laser marking program, and mark them. Then
the robot can change gripper if needed, present
parts A4 which are identified by vision, and the
laser can use the program specific to that part for
its appropriate marking. And so on.
“We are seeing the automotive and medical indus-
tries really throwing JIT production scenarios
into a more accelerated, compact format. Instead of
lots of 5,000 or 10,000 parts, an order might be for
200 parts. This demands the capability to do more
on-the-fly process changes without having to do
hard marking tool swaps.”
Robots, lasers, and data sources
combine for quick, accurate
Robots present a tray
of small medical parts
like bone screws to a
laser marker to
receive unique device
identifiers required by
Photo courtesy of
Laser heads can be mounted on a robot to take the
marking to the part rather than the part to the laser
marker. Photo courtesy of TRUMPF.