Combining effective shop-floor strategies with advanced machine tool technology has resulted in dramatic setup reductions for Land & Sea Inc., dramatically shrinking setup times from days to minutes. The Concord, (NH), shop produces thousands of the Dynomite line of engine and chassis dynamometers, which measure forces generated by a wide variety of engines or motors with rotating shafts. Applications range from industrial power plants to snowmobiles, go-karts, motorcycles, automobiles, marine engines, and trucks.
The dynamometers handle outputs of 1 to 10,000 hp (7460 kW) and vary from suitcase-size units to heavy-duty systems that can fill a 40′ (12-m) tractor-trailer. Different system versions include engine dynamometers engineered for precise collection of data as well as chassis dynamometers or “rolling roads” that measure torque and horsepower via large rotating drums turned by a vehicle’s wheels.
Land & Sea manufactures all the machine’s components, ranging from multifoot diameter drums to small aluminum connectors and steel machine housings. The shop performs machining and high-definition plasma cutting as well as fabrication operations, including welding and forming sheetmetal.
Business has been good at Land & Sea and the company’s volume of products and market share continue to increase steadily. Bob Bergeron, president, recently decided the shop’s part processing operations desperately needed advanced machine tool technology that would allow the shop to keep pace and accomplish one key goal—to reduce setup times.
“The machines we had were getting on in years, and it was time to take a look at another round of equipment,” said Bergeron. “We wanted to shorten setup times because we produce a lot of different components in small runs—typically of one to a dozen pieces. Reducing the number of setups is crucial, because any setups we eliminate can provide the best time savings of all.”
Bergeron cited an example of a part manufactured on one of the shop’s older machines. “We had to machine seven sides. The job would run six or seven working days to produce 12–24 pieces. Probably three days of setup time were embedded in those seven days. And invariably, it would seem, every fourth or so time we would run the job there would be an error in one of those setups and we would not find out until the seventh setup that there were 24 junk pieces.”
Bergeron’s research and focus on setup reduction, along with a need for expanded machining capabilities, resulted in the acquisition of a full simultaneous five-axis Variaxis i-700 vertical machining center and later an Integrex i-400S multitasking machine, both from Mazak Corp. (Florence, KY).
The Variaxis i-700’s rotary/tilt table provides multiple-surface, simultaneous five-axis machining capabilities for processing parts with complex profiled surfaces in single setups. An automatic 40-tool changer offers flexibility and permits continuous machining operations. The machine’s full five-axis capabilities enable the shop to process the seven-sided part in just two setups.
Bergeron said that the setup time for that job is now well under 10 minutes, and such setup reductions have been the case with most of the jobs the shop now does on its Mazaks.
“We realized the benefits of fast machining in terms of cycle times and in heavy material-removal part applications. But even if the machine cut at infinite speeds, for us, it would have zero effect on our long setup times,” he said.
In addition to the Mazaks, standardized tooling has also proven a key factor in reducing setups and potential tooling errors at Land & Sea. “We realized early on that we could save a lot of setup time by using standard tools,” said Bergeron. “Such standardization allows us to reduce the number of tools that we have to custom load for each new setup.”
The strategy works because Land & Sea manufactures its own products and now, whenever possible, designs part features around standard groups of tools. This is often impossible, according to Bergeron, for typical job shops because they must contend with custom part designs requiring the use of individual specific tools.
“With the Variaxis i-700, there are 29 tools that stay loaded, plus a probe,” he said. “Thirty of the machine’s 40 pockets are used, leaving 10 pockets for specialized tools when they are absolutely necessary. But a job that needs even five specialty tools is extremely rare. It is thrilling when we eliminate a tool on the list by redesigning a part, therefore eliminating the need to custom load a tool along with the required setup time associated with it.”
At Land & Sea, standardization is the means to maximum tool flexibility. For instance, the shop threads a variety of hole diameters with a single-point thread mill and can typically do many different holes—including tapered pipes—with one tool. And while a multipoint tool might thread a bit faster, it would claim an additional pocket in the tool magazine and would have to be loaded and touched off each time it was used.
Tool standardization and machine rigidity and reliability have also helped the shop reduce tooling costs. “We hardly ever break tools now,” said Bergeron. “We use the right tool all the time and have centralized our machine programming, so that none of it is performed on the shop floor. Even tool compensation codes are sent to the machines from the programming office. And in doing so, we have basically eliminated the risk of loading the wrong tools or applying them incorrectly.”
Success with its first Mazak prompted Land & Sea to purchase its Integrex i-400S that combines the capabilities of a turning center with those of a machining center. It features a second turning spindle that enables parts to be fully machined in one setup and minimizes fixtures, tools, work handling, and non-cut time. The machine can process prismatic parts from solid blocks or castings (chucked or bar-fed work), round parts or highly contoured sculptured parts. Land & Sea’s version of the machine features a 72-tool changer.
Initially, Bergeron thought a second spindle might be unnecessary because he knew parts could be quickly flipped manually. However, it became clear that such interruptions in the part process can be sources of error.
“We had plenty of parts end up in the scrap bin because they were chucked or fixtured wrong, but that doesn’t happen anymore,” said Bergeron. “When machining short runs, there is no room for error. If you haven’t made the part before, you don’t know if that manual move from one side to the other is going to give you a good part. With the second spindle, we get a good part every time, and that is critical when a job calls for making just three parts.
“We believed we would benefit from the high-speed milling, bulk stock removal and the extra precision of the machine technology, but not to the degree that it was going to pay for itself,” Bergeron continued. “High speeds and feeds are great, but we really needed the shorter setup times.”
The accuracy and reliability of the Mazak machines make it possible for Land & Sea to repeat parts months apart without any tramming in of vises, according to Bergeron. “That is huge when you are doing setup after setup on short-run pieces,” he said.