Articles & Columns

Presented this month are more programming tips to help prevent machine tool crashes.

When CNC wire EDMs came on the market in the mid-’70s, feeding wire from a spool through a machine’s elaborate series of rollers and guides was a tedious manual exercise. Luckily, electrical discharge machining was an exceedingly slow process back then, so replacing wire had to be done less frequently than on today’s machines, which erode conductive metal 10 to 20 times faster than earlier models.

The chip collection bin at a shop’s turning center is full, so a worker grudgingly begins the mundane task of moving the bin via a forklift to the chip collection station at the opposite end of the plant. Unfortunately, the bin leaks and coolant drips on the shop floor, causing the shop’s biggest customer to slip and fall while visiting to check on his latest order. There’s got to be a better way.

Careful consideration when implementing inspection processes yields efficiencies. Manufacturers continually search for ways to increase profits and reduce costs. Trying to find cost savings where chips are made makes sense and is usually where the most-significant improvements are found. However, efficiency gains can also be made in nonvalue-adding areas, like inspection.

Hypertherm Inc. designs and manufactures plasma, laser and waterjet cutting systems, as well as CNC motion and height controls, CAM nesting software and consumables. The Hanover, N.H.-based company opened a 165,000-sq.-ft. facility—Hypertherm’s newest—in Lebanon, N.H., in 2012. Among other machinery, the facility contains 26 multiple-axis, Swiss-style CNC lathes, which are used in the manufacturing of plasma cutting torch components, primarily electrodes and nozzles. The components are made of nonferrous materials.

Do you know why your last part run had a high defect rate, why parts from an outside supplier were nonconforming, and what you are going to do with those parts? If your company has a material review board, it can probably answer those questions.

Whether your shop is busy or struggling to survive a downturn, employees are your best asset. We’ve had to downsize over the past few months, but a good group remains. Many are handling new tasks, but a reengineering of employees’ tasks can be beneficial, driving everyone to work smarter, not harder. It is working well so far, thanks to everyone picking up the slack created by the departed employees. 

In today’s hypercompetitive, globalized economy, businesses are pressured to do more, do it faster, do it right the first time and do it all with fewer resources. The Internet of Things and Industry 4.0 have given birth to asset-monitoring software that should enhance competitiveness in this environment, but it can also be like turning on a waterfall of data that raises the risk of “task overload.” Faced with task overload, most people focus on what they think is most important while a seemingly peripheral task is temporarily ignored.

Lindquist Machine Corp. is a custom-machinery builder that relies on its CAD/CAM system to keep its workflow flexible, break bottlenecks and reduce lead times. The Green Bay, Wis., shop has one programmer to do complicated programming, but most of the workers on the shop floor can write, or at least modify, programs. 

... in these golden years,” crooned the late David Bowie in one of his smash hits. The term “golden years” is also used in Albert B. Albrecht’s book “The American Machine Tool Industry: Its History, Growth, Restructuring & Recovery,” which he revised in 2015 for the third edition. AMT—The Association For Manufacturing Technology sponsored the book. Albrecht defines the golden years of the machine tool industry as being from 1948 to 1998. “It was during this period that the United States machine tool industry led the world in both machine tool production and consumption,” Albrecht wrote.

Every machine tool owner can reap benefits from a good spindle maintenance program. These include reductions in costly unplanned machine downtime, longer spindle life and improved part quality. But effective spindle maintenance requires perseverance and the appropriate technology—plus a little common sense.

How often should a metalworking fluid be tested? It depends. Metalworking fluid is used in most machine shops, because it aids in evacuating chips and cooling and lubricating the tool/workpiece interface. To optimize fluid performance, it must be maintained, which is done by testing a fluid for performance and chemistry. 

Italy-based Samputensili S.p.A. unveiled a machine that eliminates the need for cutting oils when manufacturing gears, thereby reducing grinding costs. During grinding, oil-based lubricants cool the workpiece, as well as reduce friction and help evacuate chips. On the downside, however, oil use accounts for a significant amount of a grinding operation’s total cost. Expensive equipment is required to supply, chill, catch and wash away oil in grinding processes. In addition, Samputensili estimates that oil-treatment equipment accounts for 75 percent of the energy consumed by a grinding machine.

When drilling, perhaps no variable is as important as the workpiece material. It dictates drill geometry and substrate, tool coating, coolant application, and speeds and feeds. While known for its relative softness and ductility, misconceptions abound among those who regularly drill aluminum. 

Everyone crashes, I was once told. It’s likely true. However, not all crashes are created equal. There are fender benders that just break small tools, and then there are head-on collisions that ruin much more—including your day. CNC machine crashes are relatively easy to avoid. They often occur during setup and debugging. If you can recognize high-risk situations, you’ll be in a better position to avoid them.

Specifications for particulate and film-residue cleanliness are a matter of course for many machined components. In addition to the parts cleaning procedure, manufacturers must consider the entire process chain when seeking to efficiently achieve and maintain the required level of cleanliness.

Ask the Grinding Doc: When I ran out of single-point dressing diamonds and got desperate, I mounted a PCD insert to dress an Al2O3 wheel. Is there any danger in doing that?

Multiple machine tool builders offer equipment for machining the helicopter transmission components Northstar Aerospace Inc. produces at its Bedford Park, Ill., facility, but not all are equally efficient in handling the task. The parts weigh up to 350 lbs. (159 kg), have diameter tolerances as tight as 0.0003" (0.0076mm) and are made of aerospace-grade superalloys typically hardened from 50 to 60 HRC, said Brian Cheek, vice president and general manager at Northstar.

Researchers at North Carolina State University reported the discovery of a distinct form of solid carbon they estimate is about 10 percent harder than diamond and could play an important role in machining. They also claim to have developed a relatively inexpensive technique for producing the substance, called Q-carbon, at room temperature and ambient atmospheric pressure.

Cutting external threads is one of the more difficult machining operations. Achieving the proper thread form can be challenging, and tool chipping and premature tool wear are often problematic because of insufficient surface speeds and high cutting pressures.