MASEAS & ABB Cobot Help Andover Scale Optical Filter Production
Rising demand for precision optical filters forced Andover Corporation to rethink one of its most labor-intensive manufacturing processes. By automating filter chamfering with a collaborative robot, the company increased production capacity, improved quality and eliminated thousands of repetitive manual motions for operators.
For nearly 50 years, Salem, New Hampshire based Andover has specialized in manufacturing custom optical filters and coatings, used in industries such as aerospace, defense, medical, and environmental monitoring. Andover optical filters perform the task of transmitting specific wavelengths of light while blocking others, meeting the highest performance standards for mission-critical applications.
As production demands continued to increase, particularly for high-volume defense applications, one manufacturing process became increasingly difficult to sustain manually: chamfering the edges of the optical filters.
“It got to the point where we couldn’t keep up with the workflow through manual chamfering, so we decided we had to look at other options,” said Nick Sullivan, Andover’s director of engineering, who led the project.
To address the challenge, Andover partnered with automation integrator Minuteman Automation Systems of Wakefield, Massachusetts to deploy an ABB GoFa™ collaborative robot (cobot) that automates the company's highest-volume chamfering operations. The system has improved throughput, enhanced product quality, and reduced repetitive manual labor.
Growing Demand Exposed Manual Process Limitations
Optical filters begin as larger sheets of specialty glass before being cut into individual circular filters ranging from approximately 10 mm to 2 inches in diameter. Once coated to achieve the desired optical characteristics, nearly every filter requires a precision chamfer — a 45-degree beveled edge around the perimeter.
The chamfer serves several purposes. It removes sharp edges for operator safety, reduces the risk of chipping during handling, and, in many applications, provides alignment features that help customers accurately position the filter within optical assemblies.
Although essential, the process had traditionally been entirely manual.
A skilled technician would attach each filter to a wooden dowel using double-sided tape—or a vacuum fixture for certain sizes—and manually press the filter against a rotating chamfer bowl using a loose abrasive slurry. The operator carefully rotated each piece to produce a consistent bevel before rinsing and cleaning the finished filter.
The process required approximately 30 seconds per part and was repeated thousands of times for large production runs. Besides being labor intensive, it subjected technicians to continuous repetitive wrist motions that could eventually contribute to fatigue or repetitive stress injuries.
“Hand chamfering can cause wear and tear on the operator and is not as accurate and repeatable as the robot,” said Sullivan.
For many years, manual chamfering adequately supported Andover's production requirements.
However, growing demand changed the equation.
While many specialty filter jobs require only 10 to 100 parts per month, Andover's highest-volume programs now exceed 8,000 filters monthly, with forecasts continuing to climb. Maintaining on-time delivery while preserving the company's demanding quality standards required a different approach.
The company had explored robotic automation years earlier, but the technology, economics, and manufacturing process were not yet aligned. Earlier collaborative robot evaluations failed to provide the smooth wrist motion, precision and overall system performance required for precision optical work.
By 2022, however, both production volumes and collaborative robot technology had matured sufficiently to justify a new automation strategy.
Designing an Automated Chamfering Cell
Working with Minuteman, Andover implemented the GoFa cobot equipped with a 5 kg payload and 0.95-meter reach.
Unlike traditional industrial robots, cobots operate without safety fencing, allowing technicians to work nearby while the robot performs repetitive chamfering operations.
“The GoFa collaborative robot was the right fit for us because our parts are low weight, and we wanted the ability to have it work safely alongside humans without needing to be in a caged area,” said Sullivan.
Designing the system required more than simply automating manual motion.
The cobot retrieves filters from trays manually loaded by an operator after ultrasonic cleaning. Because the filters may not sit perfectly centered within their nests, the robot first transfers each filter to a dedicated centering station. A modified collaborative gripper accurately repositions the part before the robot regrips it using a vacuum end effector.
Once precisely centered, the cobot moves the filter into a rotating diamond chamfer bowl, producing a highly consistent 45-degree chamfer. When required, the filter is automatically repositioned and chamfered on the opposite side before being returned to the finished tray.
The system accommodates filters from 10 mm to 2 in. in diameter with minimal changeover, using interchangeable vacuum cups while avoiding extensive mechanical adjustments between production jobs.
“Our goal was to design a system that was intuitive for Andover's technicians to operate while minimizing changeover time,” said Rey Kelly, a robotics engineer at Minuteman who worked closely on the project. “Mechanically, that meant creating a system that could quickly and accurately center each lens without introducing safety risks for operators working nearby.
“The result is a completely modular system that accommodates a wide range of lens sizes using interchangeable vacuum cups matched to the diameter of each lens. Because it's built around a collaborative robot operating without traditional guarding or fencing, we also had to ensure the centering station remained within the required force limits to provide safe human-robot collaboration.”
Automation Improves Consistency
Beyond increased productivity, automation has delivered significant quality improvements.
The manual process relied on loose abrasive slurry that could occasionally scratch optical surfaces. The automated system's embedded diamond tooling and coolant substantially improve surface finish while providing much more consistent chamfer geometry.
Accurate part centering also proved essential.
Engineers discovered early that even slight misalignment could allow a vacuum-held filter to climb within the rotating bowl. Minuteman incorporated precision centering, specialized tooling, and carefully developed robot motion to maintain accurate positioning throughout the cutting process.
The entire system was first assembled and programmed at Minuteman before being installed at Andover, where engineers completed commissioning and operator training.
“Precision was the biggest challenge for this project. The smooth motion of the GoFa cobot was able to provide that,” added Kelly.
Productivity Without Sacrificing Precision
The primary objectives were straightforward: to improve on-time delivery while maintaining internal quality standards. According to Andover, those objectives have been achieved.
“The robot was able to deliver on all the performance metrics that we wanted; we are able to process larger orders than we ever were before, and we have no worries about quality or capacity,” said Sullivan.
A typical high-volume production run processes approximately 500 filters in just under four hours with minimal operator involvement. If the system detects an abnormal condition, such as a dropped filter, it safely pauses operation until a technician intervenes.
Just as importantly, the collaborative robot has improved workplace ergonomics by eliminating thousands of repetitive wrist movements previously required during manual chamfering.
Building a Foundation for Future Automation
Implementing the system also expanded Andover's internal robotics expertise.
"I knew basically nothing about robotics coming in," said Sullivan. "Working with Minuteman and our application over time, I have learned a ton about robotic programming, setup and operation. It's a fascinating technology."
Minuteman’s Kelly, also an adjunct robotics professor at Rochester Institute of Technology, believes customer engagement was equally important to the project's success.
"Implementing robotic automation is a journey. When you have someone on the customer side willing to absorb the technology and take ownership of the equipment, it's usually a big success for all parties."
That partnership is already influencing Andover's future plans.
As demand for precision optics continues to grow across mission-critical markets, Andover views collaborative robotics not as a single automation project, but as an important step toward expanding manufacturing capacity while preserving the precision and quality that have defined the company for nearly five decades.
