Goodrich Corporation’s manufacturing plant in Troy, Ohio makes wheels and brake systems for aircraft. The massive facility (400,000 square feet) is home to 800 employees. Their customers include Boeing, AirBus and Lear. It goes without saying that the quality in the manufacturing cells is the top priority.
One of the plant’s six machining cells is the piston-housing cell, integral to manufacturing the wheel. Goodrich had a problem in this cell, however. Long setup times on individual machines were stifling productivity. Setup times of 8 to 24 hours were not uncommon. Something had to be done, but it had to be done carefully.
Goodrich initiated a lengthy, detailed evaluation of equipment and systems to find away to reduce setup time. At the end of that evaluation process, they selected a linear pallet pool system from Mori Seiki. The linear pallet pool system purchased by Goodrich consists of three MH-633 horizontal machining centers (HMCs), each with a capacity of 240 tools, and two loading/unloading stations controlled by the Mori Seiki cell controller using CAPS-LPS software. CAPS-LPS was developed by DTL, Mori Seiki’s software division, to monitor, schedule and direct the operation of manufacturing systems.
The MH-633 HMC is the workhorse of the linear pallet pool system. Jesse Scott, Goodrich’s manager of manufacturing engineering and quality control, answers quickly when asked what carried the day for the Mori Seiki system. “Reputation,” he says. “plus the ability to talk to other customers and see other installations that were working.
“This was the single largest machine tool expenditure in our history,” Mr. Scott continues. “We took a lot of time, did a lot of homework, and went and visited many sites. It was a very extensive process.”
Goodrich’s linear pallet pool marries the three horizontal machining centers into an automated manufacturing cell. Of the linear pallet pools that Mori Seiki has installed at various companies through May 2002, the average configuration has two machines, although the capacity is eight machines.
“"After looking at the parts that were going to be run on it and what they were trying to accomplish, we thought that the pallet pool was a good fit for them,” says Bruce Cameron, an applications specialist at Mori Seiki Mid-American Sales.
Goodrich’s results have been phenomenal. In only a year’s time, the company has realized a 96 percent reduction in setup time and a 40 percent reduction in standard costs.
“It’s all but eliminated our set-up,” says Chad Sheline, supervisor of cell support engineering at Goodrich. “We have parts on demand whenever we need parts. All we have to do is load the part up, program it in the system, and it’s ready to go. So there’s basically no setup time.”
“Mori Seiki’s flexible machining center has added 30 percent machine uptime to our productivity factor,” Mr. Scott says. “We don’t have anything now but machine run time and operator run time. In our equation of productivity, the major factors are setup time, maintenance time and machine uptime. We’ve had very little, if any, maintenance time. Now, we’ve reduced the set-up time to nothing so that leaves all the time for machine and operator time. That’s helped tremendously.”
It is the cell controller that drives the system, according to Mike Jouglard, systems manager for Mori Seiki. Mr. Jouglard worked with Goodrich in configuring its system. He is responsible for procuring, assembling and installing the cell controller at the customer’s facility, and he works with DTL to customize software for each customer.
“The entire purpose of the cell controller is to remove the operator from the machine and let the system automate the process,” Mr. Jouglard says. “The result our customers realize is the ultimate in flexibility, productivity and spindle utilization. If an operator is in charge of getting the machine running and making sure that the parts are loaded and everything is in there, then there’s a lot of delay time, and your productivity goes down. If it’s all automated and the operator is not interfacing directly with the machine, you can achieve greater productivity.”
With the CAPS-LPS software, job information specific to a given workpiece is entered, then that job is scheduled to be machined. The cell controller tells the automated guided vehicle (AGV) to pick up the jobs and move them to the appropriate machine in the system. Once a job is delivered to a machine, the cell controller downloads the part program to that machine. Finally, the cell controller supplies feedback on production status, production quantities and a variety of information about the machines. This data includes time spent in operation, idle, power off, and so on. Similar data is given on the setup stations and the AGV, and a general overview of system performance is also provided. Armed with this information, Goodrich can easily calculate productivity numbers.
Goodrich’s installation of the linear pallet pool went well, too. It only took 6 weeks to install the machines. “Given the size of the configuration, it was one of the smoothest, fastest, best-run and overall excellent start-ups of any machine tool we’ve had. It went extremely well,” Mr. Scott said.
The linear pallet pool went into production in that seventh week. Then, the actual training commenced. Mr. Cameron says “That’s probably the best, because the operators actually get their hands on it, and that’s important." he says. "Until you get your hands on it, it doesn’t sink in. To me, it’s important that they can actually see the movement of the pallet pool as they tell it to do certain things, and they can see the effect of a mistake and how easy it is to recover from it.”
There have been some real successes at Goodrich with this system. On one piston housing, the reject rate was higher than normal. “Chad’s [Sheline] action plan to improve that reject rate was to take it off the stand-alone machines in two separate operations and bring it over on the FMS and run it in one operation," Mr. Scott says. To do that, he had to develop some specialized programming routines that we could not have done on our old machines, but we were able to do [them] on this machine. Our first pass yield on that part has gone from 90 percent to 98 or 99 percent now.”
Goodrich is continually discovering new uses for the system. “We’re still adding jobs to the system as we go,” Mr. Sheline says. “We’re identifying the jobs that we feel will work better over here and get the best results. For instance, recently, we took a job that was run both on a lathe and a machining center and combined it and had it run here. We’re finding more and more of those jobs.”