Kemco Aerospace Manufacturing invested in an automated robotic cell, increasing efficiency and production, to win a big customer order.
Kemco Aerospace Manufacturing located in St. Louis, Missouri has been serving the aerospace industry for over 65 years. They specialize in metallic structures and assemblies, equipped with large bed and small-bed 5-axis machines primarily, but also have other capabilities including waterjet, assembly and welding.
Kemco had the opportunity to bid on a large package of work to manufacture a single, high-volume component, which entailed producing 30,000 units annually. The company knew the quote needed to be as competitive as possible to win the order because they were competing against an incumbent manufacturer.
“We were pretty confident the existing opportunity was being fulfilled through a hand-load system where you had a lot of bodies moving parts between machine tools,” says Dan Ladenberger, President and Owner of Kemco Aerospace Manufacturing. “We knew that in order to meet the quality and the efficiency requirements needed to deliver a successful quote, we needed to bring automation to the forefront.”
Early on in the bidding process, Kemco brought in Industrial Tool, Inc. (ITI), a Minnesota-based FANUC America-Authorized System Integrator (ASI), that designs and builds custom machines and custom work holding fixtures, in addition to integrating robotic solutions. The company has over 30 years of experience with automating large machining lines using FANUC robotics. Kemco worked with ITI to determine the scope of the automation solution, including what the cycle times needed to be in order to produce a required number of finished parts over an eight-hour shift.
“Kemco wanted a truly unattended automated robotic system that not only machined the parts, but also measured every part,” says Paul Prior, Sales Engineer for ITI. “No part could be put on the outfeed conveyor that was actually a bad part. The robot would take that part and put it on a quarantine rack for later human inspection.”
As part of the automated robotic cell, machine tool distributor Maruka USA brought in three Hwacheon machines. The lathe and two mills are all equipped with FANUC 0i-F controls, which made integrating the cell into Kemco’s operations easier since the majority of its machines have FANUC controls and operators are familiar and skilled on using them.
“Because of the nature of the material being machined, we chose to use two Hwacheon 1050B vertical machining centers both box way and gear headed spindles because of their rigidity and stability in cut,” says Vern Winn, Technical Sales Engineer for Maruka USA. “We chose for the fine boring and threading work to use a Hwacheon Hi-Tech 230B because of its ability to maintain accuracy and hold tolerance through unattended runtime.”
The final cell concept has two conveyors, an infeed conveyor and an outfeed conveyor. Assisted by 3D vision, the FANUC M-710iC robot picks up the to-be-machined part on the infeed conveyor and places it in the first of two three-axis mills.
“We use 3D vision over the infeed strictly for orientating the part because the part is round and has no clocking features other than a convex shape,” says Steve Carstens, Mechanical Design Engineer for ITI.
“We knew that in order to meet the quality and the efficiency requirements needed to deliver a successful quote, we needed to bring automation to the forefront.”
The 3D vision maps the part’s curve, which guides the robot to pick up the part. Because there is no radial clocking, explains Carstens, the robot is required to locate in the machine fixture, which has no locating features. In other words, to machine the part correctly, the robot and the vision must work together to pick up the part and place it in the machine tool.
“We really rely upon the accuracy of the FANUC robot to pick that part up,” says Prior. “Without the robot being accurate enough to position that part within a half of a degree repeatedly day in and day out, we would not be able to accurately make a part.”
The robot then removes the part when finished and places it in the other large vertical machining center. After machined in the second step, the robot then moves the part to a lathe, which performs critical threading and deburring.
“One thing that was really helpful for us when we were integrating is the FANUC controls in the machining centers have a seamless handshake when it comes to integrating to the FANUC robot,” explains Prior. “That same signal that says ‘I’m ready to have a part removed,’ and ‘I’m ready to have a part loaded’ in the machines is the same signal. That FANUC signal, that FANUC handshake, makes it easier for us as an integrator to connect all the dots.”
After manufacturing is completed, the robot runs the part through an automatic blow-off station and a CMM, which collects quality data to ensure the part is to spec. If not, the part is automatically rejected. Also, assisted by the FANUC controls, if a tool breaks or wears down during the machining, the part is quarantined, which allows the automated cell to run unattended for eight-hour shifts at a time, 24-hours a day.
“By utilizing FANUC’s Tool Life Management,” says Winn, “once life is met, we are able to exchange a fresh tool without interrupting the cycle, which is important to keep cell uptime.”
Because of this project, Kemco landed the aerospace supplier contract because their quote guarantees the delivery of consistent high-quality parts at a cost that was competitive, yet still provided Kemco with an adequate margin.
“We would not have been able to win this work, in our belief, without the efficiencies and the quality environment that this cell brought to the table,” says Ladenberger. “It allowed us to win a very substantial piece of work that we would not have won, but for the automated cell and the characteristics of what ITI created and helped us integrate."