Flexible Automation Expands High-Volume Door Closer Production
As demand increased for door closers and new part variations entered production, one manufacturer needed to increase production to keep up with volume requirements. The challenge was to create a system that could handle multiple part families, absorb casting variation, reduce operator involvement, and simplify future changeovers.
The manufacturer turned to the team at All World Automation, which had built its original automated cells, to develop a shared automation platform that could grow with changing production requirements.
The team engineered two new machining cells built around a common automation architecture. Each cell paired three horizontal machining centers with three FANUC M-10iD/12 robots. Custom ARROW® Workholding Fixtures and ClampMAX® Hydraulic Power Systems handled loading, unloading, clamping, and part transfer across three machining operations.
The new cells also introduced a significant engineering challenge: upgrading to larger horizontal machining centers with 500 mm pallets instead of the previous 400 mm pallet machines while maintaining the available factory footprint. The larger machines offered increased capacity but required careful redesign to accommodate their increased height and width within the existing space.
Choosing the Process
Together, the teams selected horizontal machining centers for the new process. The door closer castings required machining on five or six sides, along with several angled features, making a horizontal platform well suited for the application.
Working with the machine builder and All World's ARROW Workholding Fixtures team, All World Automation developed a process that completed each part in three operations across three machines.
Each machining center used a custom ARROW Workholding Fixture powered by a dedicated ClampMAX® hydraulic power unit. The robot handled loading, clamping, and unloading. As castings entered the system, the regrip station was designed to set the part down and pick it up in a new orientation left by the infeed conveyor before transferring it to the fixture. This step eliminated misloads and allowed the part to be positioned for additional machining work.
One Platform, Multiple Part Families
Unlike the dedicated equipment it replaced, the new cells were designed to run up to seven door closer part families with minimal operator involvement.
Each machining center used a custom ARROW Workholding Fixture powered by a dedicated ClampMAX hydraulic power unit. The robot handled loading, clamping, and unloading. As castings entered the system, the regrip station was designed to change the part orientation left by the infeed pallet or conveyor before transferring it to the fixture, a step to allow additional features of the part to be accessed in the next operation.
A rotary turntable allowed operators to load raw castings while machining continued on the opposite side. When the finished-parts basket filled, the turntable rotated to bring completed parts forward and position them for the next batch of castings. In a three-machine, three-robot cell, the operators only had to put the raw casting basket into the load station and then go pick up the completed parts basket at the other end of the transfer line.Part accessibility drove the process sequence. Operation 10 used angled locating surfaces to position the casting, and Operation 20 locked parts flat on the tombstone so remaining features could be machined without manual handling between operations.
The platform approach's biggest advantage was scalability. Instead of developing a separate solution for each new part number, the manufacturer gained a repeatable automation architecture that could be expanded as production requirements changed.
"The fixture strategy and automation platform gave the customer a foundation they could continue building on," said Darrell Janesak, Sr. Director of Technology. "These cells can run up to seven different part families."
The fixture geometry was the hard part: very little surface area was available for locating and clamping. The challenge was finding the right combination of holding force without distorting the casting. It had to be held securely enough for precision machining while maintaining consistency from part to part.The team refined part orientation, machining sequence, and locating features until the process delivered consistent results. The same fixture platform now supports far more than the original application. Cell #2 through Cell #7 machine a range of door closer components using tombstones with interchangeable clamping nests and quick-connect fixtures that simplify changeovers as production requirements evolve.
Expanding Capacity Without Expanding the Footprint
The next phase required increasing production capacity while fitting larger equipment into a constrained footprint. Today, the manufacturer operates multiple automated cells built on the same platform, including Cell #2 through Cell #7.
Cell #6 launched with the four highest-demand part numbers, with room to grow into the full seven-part-family lineup as production requirements evolved. Adding that capacity required new infeed pallets, new robot grippers, and robotic regrip stations capable of recentering the casting between machining operations. Because every part moves through three machining centers, maintaining consistent part orientation from Operation 10 through Operation 30 was critical to repeatable results.
The larger Doosan NHP 5000 horizontal machining centers also increased the cell's footprint. In Cell 6, that footprint was boxed in further by the existing overhead crane structure. Working with the customer, the team suspended the crane support system from the ceiling instead of relying on floor-mounted supports, freeing up floor space for the automation cell.
Cell #7 presented another challenge: fitting the same larger Doosan machining centers into a space constrained by the loading and shipping area and other fixed building features. All World Automation worked through multiple layout iterations to solve for robot reach, machine accessibility, and overall cell performance, ultimately repositioning the rotary unload station to the east side of the cell.
Another integration challenge involved robot access to the machining centers. Because the robots loaded parts through the left-hand side of the machines, the existing machine frame interfered with the required loading path. All World Automation Mechanical Design Engineer Ian Baxter developed a modified structural support member that shifted the frame location to provide the robot with the necessary access while maintaining machine guarding support and structural integrity.
"Since they modified the machines and cut down the available space, we had to get creative with placement," said Mechanical Design Engineer John Brebeck. "We went through multiple layout options to make sure the robot could still reach everything it needed, while keeping the cell as compact as possible."
The result was a Cell #7 layout that cut the system footprint down in Op 20 by 2 feet while fitting larger machining centers into the same constrained space. The saved floor space allowed the manufacturer to expand capacity without disrupting the rest of the plant. Along with Cells #2 through Cell #6, the platform now supports seven part families across multiple cells, all built on the same proven fixture foundation.
