Matt joined the MMS team in 2006 after graduating from Ohio University (Bobcats, not Buckeyes!) with a B.S. degree in Journalism. Over the years, his duties at MMS have included editing product releases, managing the case study section and writing short technical pieces. As of early 2013, he’s been fully focused on feature writing. Matt enjoys traveling the country—and the world—to see manufacturing technology in action and to learn as much as possible from those who design and use it.
A good machinist is somewhat like a soothsayer, except the tools of the trade in this case are metal chips rather than bones or tea leaves. Yet according to Seco Tools’ Todd Miller, even those who understand the wealth of knowledge that can be gained from examining the shavings left over from a milling operation often overlook one key factor: the importance of average chip thickness.
As indicated by the video above, the results of attaining the correct average chip thickness for a particular insert speak for themselves. The first cut is a full slotting application—that is, 100 percent of the tool diameter is engaged. Each subsequent cut reduces the tool’s engagement. Note that the sound generated by the cutting action is virtually indistinguishable at every level below 100 percent. That’s because cutting parameters have been set with the goal of maintaining the same average chip thickness regardless of radial engagement.
Mr. Miller says aiming for that goal can go a long way toward alleviating problems with premature insert failure, poor surface finish, work hardening, vibration or deflection. Here’s why.
Every second counts at an operation that depends on seven flexible machining cells that run nearly 140 hours per week. Shown here is the company’s latest, consisting of four Makino A51 HMCs serviced by a rail-guided pallet shuttle.
Virtually any shop visit can reveal small insights or tidbits of information that readers might find useful, yet don’t make the resulting article. That was the case when I visited Applied Engineering to explore how tight control of cutting tool inventory facilitates tight control of manufacturing processes. Courtesy of project manager Brad Bohnet, here are a few examples of small process changes that have made an outsized impact at this Yankton, South Dakota aerospace manufacturer—and might do the same for your shop, too.
- Don’t wait to rapid. For a long time, standard procedure for any of the company’s 29 HMCs was to fully stop the spindle, then rapid over to the in-machine probe to check for tool breakage or wear. Now, that move starts immediately, and it is timed so that the spindle stops revolving just prior to reaching the probe. This saves only about 2 seconds, but given that such moves occur approximately 20 times per hour per machine, and each machine runs at least 100 hours per week year-round, the accumulated time savings are substantial.
- Don’t stop the drip. Broken tool alarms are sometimes triggered not by an actual breakage, but by an anomaly, such as shaving stuck on the end of a tap. Until recently, such incidents would stop the “drip feed” of programs into the machine. This could result in anywhere between 5 and 15 minutes of downtime as the operator searched for the appropriate tool to restart the program. In response, the company developed a “soft” tool alarm that stops the machine, but allows he operator to check, clean and re-check the tool without ending the drip feed. This has increased machine availability throughout the shop floor by more than 1,500 hours per year.
- Don’t overblow it. Each machine is equipped with a fan that blows chips and coolant off of tombstones at the end of a machining cycle. Given that any given tombstone might hold a variety of different parts, each with its own program, this often resulted in running the fan cycle multiple times before the tombstone cycled out of the machine. Now, the company employs a macro that runs the fan cycle only once for every tombstone. The resulting time savings of 1 to 3 minutes per tombstone adds up to approximately 750 machining hours per year.
AMT—the Association for Manufacturing Technology and the U.S. Cutting Tool Institute (USCTI) are collaborating on a new monthly data release that tracks an important index of manufacturing activity: cutting tool consumption. Given that cutting tools are the prime consumable in the manufacturing process, this analysis can provide a true measure of actual production and serve as a valuable leading indicator of future U.S. manufacturing activity, the organizations say.
Released August 14, the first iteration of the Cutting Tool Market Report (CTMR) shows that cutting tool consumption declined in June. Still, USCTI’s president expressed reason for optimism throughout the rest of the year. Click here for more detail.
Tom Bohnet (left), company president, and his son Brad Bohnet (right), project manager, say their new approach to tool management helps reduce scrap and rework by eliminating process variation.
The fact that an article about Applied Engineering’s approach to tool management will appear in our upcoming “Top Shops” issue is pure serendipity. Although I’d initially targeted that issue because of convenience and scheduling concerns, it soon became apparent that the article would complement coverage of the benchmarking program on a couple of levels.
For one, it demonstrates the importance of robust data in decision making—and that’s a key part of what Top Shops is all about. The idea behind the benchmarking program is to compare key performance indicators with industry leaders and make changes accordingly. Similarly, Applied Engineering’s approach to revamping the tool crib involved collecting and analyzing years of performance data on each individual cutting tool to see where improvements might be made. The result, in both cases, is better processes that deliver better outcomes.
A more direct tie-in relates to another critical part of the message behind Top Shops: goal-setting. Brad Bohnet, project manager at Applied Engineering, says the company is actively working to become one of next year’s Top Shops after failing to make the cut last year. To that end, it has taken the results and best practices from the Top Shops survey results and turned them into specific objectives. These include finalizing a 6S program, conducting more customer tours, and increasing book-to-quote ratio, sales dollars per employee, and R&D investment. The company has been using a project board to track both its progress and the obstacles it runs into along the way, and Mr. Bohnet says it hopes to be ready to apply for Top Shops again in 2014.
Judging from what I saw during my recent tour of Applied Engineering, I would be surprised if the company didn’t make next year’s list. The company’s tool management strategy is just one example of a general approach to business that mirrors Top Shop’s emphasis on adopting an evidence-based approach to setting and pursuing improvement goals.
Inspection of aerospace jet engine blades as well as industrial turbine, marine and compressor blades is among the most suitable applications for Nextec’s laser measurement systems.
Two recent MMS articles covering metrology advances should be of particular interest to manufacturers serving the automotive and aerospace industries. First, Renishaw has developed a new probe option for its Revo five-axis measuring head that enables users to measure surface finish on CMMs rather than with hand gages or dedicated machinery. The second article describes how Nextec Laser Metrology's laser systems use a different approach to beam triangulation and an adaptive control to provide a faster alternative to touch probes for parts with minute, sculpted features, shiny surfaces, and other features that often pose problems for non-contact systems.