By Jim Montague, Executive Editor
The show must go on. In manufacturing, this means keeping your machines and production lines up and running no matter what. And, if you compete globally and export machined parts to Asia, Europe—or anywhere else for that matter—then it's a good bet your customers aren't very concerned if you can't get support for the machine that makes those parts. If you can't deliver, they'll just find another supplier.
This was the challenge facing T&L Automatics (www.tandlautomatics.com) in Rochester, N.Y., which makes 60 million to 80 million precision-machined parts per year, usually with complex features and intricate details for manufacturers in the automotive, aerospace and defense industries (Figure 1). The company started as a screw-machine shop in 1974, and later added CNC lathes and transfer machines, which move parts around within work cells. T&L can machine 1/16 to 7 in. square parts—about 85% of which go to automotive manufacturers.
To achieve required precision and productivity levels, T&L Automatics had to improve the capability, reliability and output of its machining centers. For example, the original control systems on its six Imasflex seven-station, dial-index machining centers were experiencing frequent shutdowns and significant downtime at least once per week. Also, the maintenance contract fees to correct control problems were costing T&L tens of thousands of dollars per year.
"The machine builder no longer had a presence in North America, so they weren't available for support or repairs. We were on our own, and so we basically had to become our own machine builder," says Tom Hassett, T&L's president and CEO. "Still, we run these machines every day, so we know their individual circumstances. It also helps that we're not afraid to try anything."
To Pick a Partner
T&L met with local system integrator Unique Automation (www.uniqueautomation.com) of nearby Palmyra, N.Y., and together they decided to retrofit T&L's Imasflex centers by replacing their old, problematic CNC controllers and hard-to-maintain, point-to-point wiring with Mitsubishi C64 CNC controllers, Q-Series programmable automation controllers (PACs) and operator interfaces—all tied together with CC-Link (www.cclinkamerica.org) networking. Hassett adds that Unique Automation wrote the software for the controllers, and T&L's own IT staff can add to their ladder logic programs as needed to provide index-on-the-fly, run-in-parallel or other functions.
"We're always seeking new capabilities and ways to reduce costs," Hassett explains. "In engineering meetings, and sometime even when we're quoting a project, we'll ask ourselves if we can get some new performance, and then we'll test it. Customers just look at the parts they want, and so we figure out the fastest and best ways to do it. If that means changing a standard machine into a specialized one, we'll try it. About 80% of our projects have some special task in it. Since about 2003, we've seen the U.S. manufacturing base shrink, but we didn't want to be blown away, and so we constantly innovate to stay ahead. We try not to raise part prices, so we try to offset increased expenses by being more efficient and productive. Not all ideas work, so we rethink, retry and just keep digging."
Two Networks Better Than One
The upgraded Imasflex machining center consists of seven machining stations, each with an X, Y and Z axis, as well as a spindle control (Figure 2). An eighth station is used by the operator for loading and unloading. To add CC-Link to the machining center, Unique deployed the PAC with two CC-Link master stations to control two independent CC-Link networks.
"This CNC controller is more capable because it can run two machining stations from one CNC controller, and then the PAC acts as the traffic cop between the CNC controls, other machine controls and the operator interface," says Joe Gerbig, Unique's owner and operations engineering manager. "CC-Link allows us to have our local and compact I/O at each station, and only run one common cable back to the PAC. This gave us huge savings in material and labor. The only long-haul wiring left is for servo motor power and feedback cabling back to amplifiers."
The first CC-Link network includes four CNC controllers to manage the seven machining stations. Each controller is a local station device and occupies four CC-Link network stations. Three CNC controllers manage six machining stations having X, Y and Z axes and spindle control for a total of 24 axes of control. The fourth CNC controller manages the seventh machining station with four axes of control. So the first CC-Link network serves a total of 28 axes of movement. This CC-Link network handles more than 1,000 I/O points for communicating status to the four CNC controllers as well as transmitting commands to control other functions of the machine.