Laser Die & Engineering (Kentwood, MI) manufactures assembly machines, check fixtures, plastic injection molds and compression molds for a variety of customers in the automotive industry.

Among its many systems, the company builds a line of machines that assembles multiple styles of automotive headliners, accommodating the variety of shapes and trim details required by different automotive models.

Because there are subtle differences between headliner types, the machines require highly accurate control devices to perform multiple inspections as the headliners pass through a series of workstations. Fiber optic sensors are ideal for performing these tasks, because of their ability to fit into tight spaces and detect small objects.

One of the company's machines employs as many as 20 fibers to verify that the through-holes in each headliner are correctly positioned. Another set of 30 optical fibers confirms the presence of hardware used to attach the headliners to their automotive frames. In both cases, the workstation employs a bar code reader, which reads a 2D label on the headliner, to ensure that the correct inspection program is being implemented.

Because it was using so many fibers, Laser Die & Engineering found itself running large wire bundles to the many fiber optic amplifiers required to power the system. It also found that so many amplifiers required a prohibitive amount of time-consuming programming.

To fix these problems, it began installing multichannel fiber optic controllers from ifm efector (Exton, PA) in its headliner assembly machines. These controllers use a single amplifier to program up to eight fibers. All power and output wiring is accomplished with a single quick-disconnect cable assembly. Wiring is reduced to 10 wire connections at the PLC. Previously, the same application with traditional amplifiers resulted in eight cables and 24 wire connections at the PLC.

Sensor adjustment is also much faster, thanks to the controller's backlit LCD display and pushbutton programming. This LCD display offers enhanced monitoring capabilities and provides a variety of display screens for reading operating status at a glance. For example, excess gain can be monitored via a bar graph display that illustrates the amount of gain detected by each fiber. Signal strength and switchpoint threshold can be measured numerically or via an analog graphing feature.

A variety of programming options provides increased application flexibility using the controller's intuitive menu structure. For example, two separate switch points can be programmed on one fiber as a means of performing part verification operations. Similarly, logic functions using the system's "and-or" functionality can be employed in inspection and error-proofing applications.

In the case of Laser Die & Engineering, the company's headliner machine uses the logic "and" function for its through-hole verification. In doing so, the controller is able to reduce each group of eight outputs to a single output, greatly reducing the I/O and wiring required for this particular operation.

Overall, Laser Die & Engineering estimates that by using multichannel controllers, it has reduced its cost per fiber from $150 to $92-a 38 percent savings.

For more on automated assembly machines, call 616-698-0590, visit or eInquiry 2.

For more on optical inspection technologies, call 800-441-8246, visit or eInquiry 3.