The assembly process did not require a lot of steps. Once the molding process was complete, four compression limiters would have to be installed on each part, and 3M Thinsulate would need to be welded to the inside of the part for heat reduction. However, instead of multiple assembly stations with separate operators for each step, the manufacturer wanted one synchronous machine to complete all the processes. Floor space was also at a premium.

An automated system was the only option, since the process required fast cycle times and the manufacturer wanted to minimize labor costs. Reducing the number of operators and assembly stations would provide a better ROI for the line.

To meet this demand, AMS looked into developing an automated system that would only need one operator.

Two SCARA robots weld insulating material to a plastic part. A third SCARA unloads the finished assemblies. Photo courtesy Epson

The Right Components

The automated system needed to perform all the operations concurrently. The system would be built around a five-position rotary indexing dial. Parts would be loaded at the first station. At the next station, a pneumatic press would install the compression limiters. The next two stations would ultrasonically weld the insulation material. The final station would automatically unload the assemblies, separating them to “good part” and “bad part” chutes.

As AMS engineers began designing the system, one thing quickly became clear: Robots had to be part of the equation. SCARA robots would fit nicely into the rotary dial design and provide the reliability and performance that the manufacturer was looking for.

Although AMS engineers were familiar with ultrasonic welding, integrating the technology with SCARA robots was new to them. Instead of positioning the part manually or using a custom fixture to position it beneath an ultrasonic welder, engineers chose the robots to automate the process for greater speed, lower costs and better results.

Their robot of choice was the T-Series all-in-one SCARA from Epson. This space-saving robot can be deployed quickly since the controller is built into the base of the robot arm. The robot uses the same intuitive software and powerful features found in Epson’s high-end robots.

Sensors check the quality of each assembly. Photo courtesy Epson

The T-Series robots are fast, easy to integrate, and take less time to install than gantry systems. With reach distances of 400 and 600 millimeters, the T-Series can handle payloads of 3 or 6 kilograms. Engineers placed a T6 SCARA robot at each of the two stations to perform ultrasonic welding, and they deployed a T3 SCARA at the final station to unload the finished assemblies.

Initially, AMS engineers planned to use a gantry system to unload the assemblies. However, since they were already using two Epson SCARAs to do the welding, employing a third SCARA to unload the machine made more sense. It saved setup and design time, reduced the overall cost of the machine, and increased reliability.

A Satisfied Customer

AMS built a system that met the manufacturer’s price, performance and assembly requirements. During final acceptance testing, AMS engineers had to make a few pin modifications to the fixture due to unknown part variations. Ultimately, the manufacturer was satisfied. In fact, the manufacturer was so pleased with the Epson robots that it later deployed additional Epson machines at other areas in the assembly plant.

For more information on assembly robots, visit https://epson.com. For more information about automated assembly systems, visit https://amsmachinesinc.com.

For more information on robotics, read these articles:
Low-Cost Robotics for Adhesive Dispensing
Robots Automate Assembly of Automotive Connectors
Robots Assemble Medical Device on Rotary Indexers