Robots used to be a big deal. Forests of huge yellow, orange and white arms juggled and welded car bodies, and everyone else looked on in awe at their amazing moves and equally huge price tags.
Times have changed, and many robots appear to be showing off less, even as they do more and different jobs. They're diversifying in their sizes, skills, applications and costs, and so mom-and-pop end users can now afford to use them to pack tortillas, pick and place candies, or perform material handling and other smaller-ticket tasks. As a result, many robots are settling into lives of calmer domesticity, and serving in less glamorous, more unassuming roles in many machines, work cells and production lines next to traditional equipment.
To better coordinate these joint efforts, controllers and software are gaining the ability to add robots as regular devices in the repertoire of machine tools, conveyors, motors and other equipment they're already controlling. Surprisingly, some users are finding that older gantry robots and x-y-z motion systems can take on some of the jobs for which they initially thought they'd need a newer robot. Conversely, a few robot controllers are adding external devices and functions to the tasks they're already managing. In short, some robots are integrating so closely into their machines that they're becoming seamless and almost invisible in some cases.
No doubt the most frequent example of robots breaking free of previously inflexible roles has been relocating them between machining centers to load and unload materials and parts that used to be handled manually. Some robots are even installed on rails, so they can roll between machines and cells and serve more of them.
For instance, Absolute Machine Tools in Lorain, Ohio, and its electrical discharge machining (EDM) division in Mason, Ohio, have been integrating robots into their EDM processes for a couple of years. Absolute is an importer and distributor for Taiwan-based Tongtai Group, and so it recently developed a robotic interface between its Accutex DS-550 EDM die-sinking machine and Tongtai's TMV-510G graphite machining center by using Fanuc’s M-20iA robot and 31iMB controller (Figure 1). The machining center produces customized electrode tooling as needed, which the die sinker can use to make a greater variety of it own products. EDM machines use charged wires and other components to remove metal and create intricate and specialized molds and other parts that can't be made by other processes.
"We knew about Tongtai and Johnford machines in Taiwan that already incorporated a robot right into a machine, but our EDM group's technical director, Mark Cicchetti, had the idea of moving the robot outside the cell, so we could use it with existing machines," says Michael Barr, service operations manager at Absolute. "Most EDM machines already have tool changers with different electrodes, and so the next logical step is machining just the particular size that's needed for a job. The initial CAD program for a tool goes into the machining center, which tells the robot when it's done, and whether to transfer the tool to the die-sinking machine. The robot and machines communicate serial data via Ethernet and RJ45 connections. We were able to integrate this project in about 30 days, and we became certified Fanuc integrators in the process."
Barr adds that bringing the machining center, robot and die sinker together is enabling Absolute to improve the productivity of its customers, especially when they're programming and preparing electrodes and work pieces and making the builder more globally competitive. "Users can spend $35,000 to $40,000 on a traditional tool changer with a shuttle and carousel, but the EDM machine still only has a limited number of electrodes," adds Barr. "Adding a machining center and robot means the EDM machine can access an unlimited number of electrodes, change work pieces in and out automatically and do off-line set up of the next job while the machine is running. This means less idle spindle time. Saving the 15-30 minutes on average it takes to set up a typical 3.5-hour EDM job might not seem like much, but over 24 hours it can allow a user to produce seven parts per day, instead of six. At about $210 per job, this can add up to an extra $46,000 per year and maybe pay for another operator."
Flexibility Fuels Acceptability
While some machine builders are new to adding robots, others have been integrating them for years, and many of these are in the packaging industries. Sean Wells, senior robotics product manager at KHS USA in Waukesha, Wisconsin, reports his company has been working with robots since 1996 because its customers wanted greater flexibility in their filling and packaging applications, and KHS found that robots allowed them to change product types and package sizes more quickly.