Saturday, June 2, 2007

PC-based CNC revives vintage machines

SHOP SOLUTIONS

They just don't build machine tools like they used to, according to Andy Vige, president of Machine Specialty and Mfg. (Youngsville, LA).

Vige couldn't find a new machine tool that could take the punishment that one of his 20-- year-old Warner & Swasey lathes could. He'd been buying used W&S machines for years, then driving them hard to make pipe pressure fittings and flanges for the oil industry. The iron in them was still good, but the original controls were not. Aging hardware-based CNCs on the lathes had become obsolete, and because they were proprietary, closed systems, the controls were starting to cost the company plenty.

"When a motion board goes on one of these, it takes weeks to repair or replace them," Vige says.

"Frequently, the original control company can't help us at all. When a machine goes down, and you fail to produce 300-400 pieces of flange that you would normally sell during the day, you feel it." To top it off, Machine Specialty and its competitors were in the middle of a two-year price war, and the company couldn't afford to lose ground.

The solution Vige found was so successful that, 18 months later, he has transformed almost every CNC machine he owns and improved production by 30%. And he did it without buying a single new machine.

That solution was OpenCNC software from MDSI (Ann Arbor, MI), an open-architecture CNC package that uses no proprietary hardware or motion control cards. Because it runs on off-the-shelf PCs and Microsoft Windows operating systems, users are not locked into proprietary arrangements for hardware, control repair, or control upgrades.

Vige credits the package with helping him:

* Reinvigorate his old machine tools

* Gain access to machine data that helps him manage his company

* Avoid having to buy new machines

* Gain control over production

* Stay competitive.

* OpenCNC gave me a jump on everybody I compete against," he says.

Machine Specialty has been in business more than 20 years. With about 75 employees, the company makes pipe Ranges and fittings for a variety of oil and gas applications, from deep-water drilling in the Gulf of Mexico to the North Sea, where they perform critical applications such as containing high-corrosion fluids or withstanding pressure of up to 20,000 psi (138 MPa). The business is competitive and global.

As company president and coowner, Vige constantly looks for manufacturing solutions to help him optimize profits and resource utilization. Machine downtime costs money-$8500 per day per machine, Vige estimates. He figured his Warner & Swasey lathes were down about 20% of the time with control problems. When he realized he was spending $2,000-- $3,000 per machine per month to keep the old controls going, plus what it was costing him every time a machine stopped, enough was enough.

Besides upgrading his old machines, Vige was looking for answers to several manufacturing problems. He wanted to decrease cycle times. He wanted a control that in-house maintenance personnel could service. He wanted to use existing servos and drives. And most of all, he wanted access to data.

"I needed a better tracking system for what was going on with each machine," he says. "How long is the machine running each day? How long does it take to do a batch of parts? How many parts can be done in one day per machine? I can't get this information from traditional controls."

When Vige heard about OpenCNC, he knew it was what he wanted. "It was software that let me use any drives that I wanted or any PC," he said. "I didn't have to buy a whole package. I could buy the best drives or the best PC I wanted. The MDSI control doesn't care which one you use. It's software, so we can put it into any package we choose."

The first machine retrofitted with the software was a W&S 2 SC lathe. Eldon Richardson, an MDSI integrator out of Meridian, MS, performed the retrofit, which involved pulling all the wiring from the old cabinet, removing the old control, installing OpenCNC on a new PC, rewiring the panel, and programming the machine. The old servos and drives were in good shape, so he left those in place.

Machine Specialty machinist Mike Thibodeaux worked with Richardson to learn about the software. Since that first machine, they have refined the retrofit process so that Thibodeaux and other Machine Specialty employees strip out the old control and remove all the wiring. At his shop, Richardson builds a bolt-on case for the monitor and PC, loads the OpenCNC onto the PC, and programs it. He then takes the completed package back to Machine Specialty, where he re-wires the machine and puts the new control in place.

Richardson says the process goes quickly if existing servos and drives are kept, which is what Machine Specialty chose to do on most of its machines. "The first machine took about two weeks," he says. "Now, it's much faster. We have actually taken four machines down at the same time, retrofitted them with OpenCNC, and had all four of them up and cutting parts in just eight days."

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