One company completely changes its culture for manufacturing commodity parts
PGI purchased three new Mazak Multiplex 630 twin-spindle/twin-turret multi-tasking turning centers with live tooling for milling, drilling, and tapping. Integrated robot part handling using Mazak GL-200N gantry robot loading systems are also used.
One of the unusual ideas born out of PGI's Team Key include the material handling pallet system. To cut costs, a special ABS thermoformed pallet system that nests six different parts, both cut and uncut, was developed.
At PGI, Multiplexes manufacture 200,000 parts per year originally done on single spindle CNC lathes and mills. The result is a 30% increase in production due to greater machine throughput.
PGI realized that to expand and produce world class products efficiently it needed to manufacture its commodity parts differently. To do this, the Team Key concept was developed emphasizing a total culture change in the company.
Contract manufacturing shops know that finishing more jobs faster, without compromising productivity, quality, or customer relations, is not always an easy task. And just adding more machines isn't always the solution, believes Precision Group Inc. (PGI), a non-captive machining company based in Rockford, Ill.
When the company expanded its product line, it first revamped its manufacturing processes and, ultimately, the way it conducts business. Only then did it go after new equipment.
In effect, when PGI decided to institute what it terms its "Team Key" concept, it underwent a complete culture change, becoming more product-focused and placing a greater emphasis on quality and one-stop shopping. Now PGI examines the entire process of part production to optimize it and the end product. Using customer-supplied drawings, PGI coordinates raw material suppliers and internal purchasing and scheduling departments with the proper machine tools, and tooling for equipment. It also evaluates secondary operations, such as grinding and deburring, and final JIT delivery to the customer.
"Today, engine and equipment manufacturers are looking to consolidate the number of suppliers with whom they conduct business," says David Morgan, PGI president and CEO. "Our ability to design and build the necessary tooling, develop the prototype, and take an active part in high-volume production, has proven a real benefit."
How much of a benefit? How about a 30% increase in production for starters?
After PGI was awarded a large, multi-year contract to produce diesel engine shafts in late 1997, the company soon realized that its single-spindle CNC lathes could not handle the increased workload. The company then re-examined its entire parts production process, looking for ways it could work more closely with its customers to optimize the end product while keeping production costs low.
How did PGI do it? Les Anderson, plant manager, says it would have been impossible had the company not purchased and installed the right machine tools. After researching four companies, all of which offered comparable machines that could meet its needs, PGI finally settled on three of Mazak's Multiplex 630 twin-spindle/twin-turret multitasking turning centers, which feature live tooling for milling, drilling, and tapping in one machine.
While other machines may have also featured twin spindles and live mill tooling, Anderson says none of them offered enough horsepower for the live tool that PGI needed to make heavy cuts. He says the Multiplex 630 offered the capabilities of a vertical machining center and a lathe in one unit, not to mention the ruggedness and spindle power PGI needed to take on the increased workload.
With its twin spindles and twin turrets, the Multiplex 630 machines both sides of a part with an automatic in-machine handoff to the second spindle. The live tooling for tap-ping, drilling, and milling also lets PGI finish parts without conducting any secondary operations.
The five part numbers produced on the Mutliplexes fit in a 6 66-in. envelope, all made from either 4120 or 4118 steel. The machine also features a 12-in. chuck with a maximum cutting length of 25.6 in. The 30-hp main spindle motors produce speeds of up to 3,000 rpm, and a 10-hp rotary tool spindle motor on the turret runs at 1,500 rpm.
Each spindle on the Multiplex 630 has a 12-position drum turret which indexes in 0.9 sec/one step (2.2 sec/full step). Rapid traverse rates for X and Z are 945 ipm, the C axis is 100 rpm.
Mainly, Anderson attributes the production increase to greater throughput. Operators can now keep all the parts in one machine. "This way, they don't have to take the part from a turning operation to a secondary operation, and they don't require any additional machine tools to get the job done," he says, adding that the company has also eliminated the fixtures for these operations. "Now, if a part modification or re-design has to be made, all that is normally required is a program change," Anderson remarks. "There's no longer a need to re-design and build new fixtures."
Because there is less handling, fixture-induced errors, and scrap, production costs have been kept to a minimum. Likewise, the company optimizes spindle uptime by keeping the machines running 22 hours a day, seven days a week, and by using robotic parts handling equipment.
Each robot hand gripper can hold parts as heavy as 22 lb, for a total weight for two grippers combined at 44 lb. The Multiplex robot loader/unloader system features a 1.97 to 11.81-in. gripping diameter for chuck workpieces and a 0.79 to 4.72-in gripping diameter for shaft workpieces.
The Multiplex 630 also uses Mazak's new Mazatrol Fusion 640 CNC, a 64-bit RISC processor for CNC control with all the front-end capabilities of a PC. It offers accelerated computing speeds for spindle and axis controllers; faster, more efficient lookahead machining capabilities; smooth high-gain servo controls; and toolpath optimization.
The Windows operating system gives Mazatrol Fusion 640 bidirectional communication capabilities with other factory PCs. Its PC control can deliver daily and weekly status reports for spindle load, spindle speeds, part counts, and machine status in real time. Another benefit is that users can access this information from a remote office.
Anderson says, "If a special part is needed while I'm not at work, I'll be able to communicate with the machine and have it automatically run the part without any operator involvement."
Other innovative ideas born out of PGI's Team Key concept include the material handling pallet system used on the Multiplexes. To cut costs, PGI personnel developed a special ABS thermoformed pallet system that nests six different parts, both cut and uncut. It is designed to handle part positioning tolerances of ±0.030 in. for the robot gripper. Pallets like this could cost thousands of dollars, but PGI created and produced them for just $65 each. Gripper jaws for the two robot heads were also produced in-house.
What technologies being developed today have the potential to revolutionize manufacturing processes in years to come? Several manufacturing executives from the aerospace, die and mold, semiconductor, contract manufacturing, transportation, and energy services industries had the chance to ponder that question more carefully when they took part in Mazak's 80th anniversary celebration this fall.
As part of the event, guests were invited to tour Mazak's Japanese facilities and view several of the company's latest developments and works in progress. Among the technologies featured were 37 new machine tools, some ready for market and others still moldable by customer input.
Among the highlighted developments were super-efficient motors, new bearings and lubrication systems for 50,000-rpm spindles, shockless servo systems, semi-dry machining systems, and advances in CAD/CAM technology for complex 5-axis work.
Numerous offline software tools, designed to more than double spindle cutting uptime by eliminating wasted time on the plant floor, were also featured. The first modules include: