Mention automation, and most people think high-volume production environments in which millions of parts are pumped out on a regular basis. While that may be true in many instances, it is definitely not the case at Choice Precision Inc. in Whitehall, Pa. In fact, the situation is quite the opposite.
Choice’s lot sizes usually run only 20 to 50 pieces, and at any one time, there can be upwards of 1,000 different open jobs in various stages from engineering to packaging – a typical jobshop environment. However, with the amount and levels of advanced automation Choice has incorporated within its manufacturing operations, one would assume job volumes to be much higher.
At Choice, production volumes do not dictate the use of automation. Instead, the shop automates for production flexibility, to boost the output of its advanced machine tool technology and its highly skilled machinists, as well as to reduce cost per part. Automation also plays a critical role in achieving shorter job turnaround times and streamlining workflow through the shop. On the whole, automation is what keeps Choice competitive and able to continuously win new work.
In business since 1992, Choice grew from a small garage-type shop to one that now employs 46 people and specializes in serving the automation market. The shop manufactures highly complex components for industrial and factory automation systems used in such industries as paper processing, automotive, product packaging and biotech. Choice’s components can be found on overhead robots, gantry loaders, pick and place robots, end of arm tooling for robots or within production assembly lines.
With so much experience and expertise in automated systems, Choice’s incorporation of automation into its own manufacturing operations seemed a natural progression. And the shop did so, as early as 1998 with the installation of two PALLETECH Manufacturing Systems from Mazak Corporation.
From the time it opened its doors for business, Choice has partnered with Mazak for machines and automation. Currently, all the shop’s turning and milling machines – a total of 29 – are Mazaks. And the shop’s automation includes three Mazak PALLETECH Manufacturing Systems, bar feeders, gantry loaders and robots.
With these types of automation, Choice incorporates all four of Mazak’s 4 Levels of Automation – Bar Feeders, Gantry Loaders, PALLETECH Systems and Articulated Robots. The 4 Levels of Automation are part of Mazak’s 3-4-5 The Next Level of Productivity manufacturing solution, the industry’s most comprehensive grouping of manufacturing resources and one that encompasses Mazak’s 3 Levels of Control, 4 Levels of Automation and 5 Levels of Multi-Tasking. 3-4-5 allows manufacturers, such as Choice, to effectively identify the right level of technology, including automation, needed for improving their specific operations and advancing productivity.
Choice’s PALLETECH Systems – two of which are paired with 320-tool capacity Mazak Tool Hives – are modular in design and can expand along with the shop’s growing production demands. Three types of pallet stocker layouts – one, two or three level – can be selected with Mazak’s PALLETECH System based on available floor space and the number of machines incorporated in the system. All levels of PALLETECH Systems allow for expanding with additional machines and pallets within the existing System.
The two single-level PALLETECH systems at Choice service the shop’s lines of HORIZONTAL CENTER NEXUS (HCN) Horizontal Machining Centers – two HCN 6800s in one cell and two HCN 580s in the other. The third system is a double-level 12-pallet stocker station configuration that serves a recently acquired Mazak VARIAXIS 730-5X II full 5-axis Vertical Machining Center, and the shop plans to add another machine to that cell.
Automation goals
According to Greg Willet, general manager at Choice Precision, the shop’s goal with its three PALLETECH Systems is to load them with as many different jobs as possible. This, he said, not only increases efficiency for each individual job, but also allows for continuous machine operation, which is also why the shop opted for Mazak’s huge Tool Hive tool storage systems to accommodate all the necessary tooling for these different jobs.
“Typically, we’ll set up each pallet of our PALLETECH Systems with several completely different jobs,” explained Willet. “So we are running about 100 to 150 different jobs at the same time. Plus, we’ll keep certain job fixtures on pallets because we know the customers will want more parts in a month or so.”
Even for parts with multiple operations, he said that the shop always tries to run whole jobs on one pallet using four-sided tombstone fixtures. For instance, parts ready for operation one are clamped on the first side of the tombstone. They will then be moved to another side for operation two, another side for operation three and so on until they are completed. This has significantly improved consistency in accuracy because parts are not traveling to various setups on different machines.
The bulk of the shop’s parts are made from stainless steel, Inconel, ductile iron, steel and aluminum. With small lot sizes, optimum speeds and feeds must be quickly established with the first part. And determining reasonable starting points is typically reliant on the experience of Choice’s machinists.
Beth Rothwell, president of Choice Precision Machine, added that just because the shop has such advanced levels of automation as its PALLETECH Systems, does not mean there is any less of a need for skilled labor. Quite the contrary, and in fact, she said that automated systems require machinists with even higher skill levels. As opposed to just mastering an advanced machine tool, machinists must have a thorough understanding of the automation, processes and workflow through the system to get the most out of the machine tool and the automation.
According to Paul Sickels, design engineer at Choice Precision, the shop’s highly advanced manufacturing operations require that machinists know how to program, build fixturing to a certain extent, set up jobs, choose optimum tooling and determine part flow through automated cells, besides knowing how to machine a part.
“Additionally, we do all our programming at the machines because it is much faster, especially with the Mazak MAZATROL CNC control’s interactive style input,” explained Sickels. “Our machinists do get support from the shop’s two design engineers when needed, but for the most part the machinist at the machine is the key to the success of a job.”
At Choice, each machinist is completely responsible for all workflow through a machining system. And the goal of that workflow management/scheduling is keeping machine spindles running as much as possible. So, jobs with long cycle time parts will run at night, while shorter cycle time jobs run during the day. Workflow is very dependent on job lot sizes, part complexity, tooling required and other characteristics of the job. To assist in optimizing workflow, Mazak provided training on cell management of the PALLETECH and Mazak’s cell management software, which works in unison with existing job scheduling MRP/ERP software at the shop.
5-axis and Multi-Tasking for the future
“We are a Mazak shop,” said Beth Rothwell. “Staying with one supplier gives us consistency throughout the shop floor – consistency with our employee base in terms of training, with machine maintenance, tooling and controls/programming. By standardizing, our machinists easily run one machine one day and a different one the next day. Additionally, and most importantly, our partnership with Mazak has resulted in us incorporating some of the industry’s most advanced technology, including 5-axis multi-tasking and full 5-axis milling, in addition to automation. We rely on Mazak to keep us at the cutting edge of manufacturing.”
For instance, the shop’s recently installed VARIAXIS 730-5X II 5-axis Machining Center and an INTEGREX i-200S Multi-Tasking Machine featuring twin spindles and gantry loader – have significantly boosted the shop’s 5-axis and Done¬-In-One machining capabilities. The machines allow the shop to easily and efficiently process those parts with complex geometries and requiring multiple machining operations, as well as full simultaneous 5-axis machining.
The VARIAXIS 730-5X II is a high-performance, high-speed, heavy-duty, 5-axis machine for larger sized, complex parts. Its powerful 50-taper spindle gives Choice a maximum spindle speed of 10,000 rpm and 40 hp for aggressive metal removal rates, while a 1,654 ipm rapid traverse rate in the machine’s X-, Y-, and Z-axes helps significantly reduce cycle times. For high-precision 5-axis machining, a built-in tilt/rotary table provides A-axis tilting of 150° and C-axis rotation of ±360°, both in increments as small as 0.0001°.
Additionally, the VARIAXIS 730-5X II is equipped with Mazak’s new MAZATROL MATRIX 2 CNC control. Within the control are both enhanced hardware and software functionalities for high accuracy, superior surface finishes and faster cycle times. Control hardware performance provides higher processing speeds for small increment operation. Furthermore, a 5-axis spline interpolation function included in the control’s 5-axis software package provides smooth toolpaths from long block-by-block programs, easy tool vector control, shorter cycle times and superior part surface finishes.
Choice’s INTEGREX i-200S Multi-Tasking machine with its twin turning spindles allows the shop to productively turn, drill, tap and mill, in addition to off-centerline and full simultaneous 5-axis contouring. The machine falls within Mazak’s Done-In-One concept as it incorporates all processes from raw material input through final machining in a single setup. As such, it reduces Choice’s production lead times, improves machining accuracy and lowers the shop’s operating expenses.
“What we see driving today’s 5-axis and multi-tasking machining is Mazak’s Done-In-One concept,” explained Willet. “This concept is what allows us to produce highly precise parts because we no longer have to first turn a part on one machine, for instance, then move it to another machine for milling and back to the first machine for more turning. When parts come off the INTEGREX i-200S, they are complete, and such capability is the key to machining accuracy and eliminating the risk of stacked tolerances. For us, Done-In-One is not only a tool for capacity or production efficiency, but more importantly a way to improve throughputs and cost effectively producing our 20 to 50 job lot sizes.”
Both turning spindles on the INTEGREX i-200S provide equal high performance with spindle speeds of 5,000 rpm and C-axis control (0.0001° indexing increments on the main spindle and 0.001° increments on the second spindle). And both have a bore capacity measuring 3” in diameter. The main headstock features an integral spindle/motor that can accommodate a wide range of applications, from heavy-duty cutting at low speed to high-speed cutting of aluminum and other nonferrous materials. The second spindle also features an integral spindle/motor to ensure high efficiency machining for secondary operations.
The INTEGREX i-200S vertically mounted milling spindle provides 30 hp, 12,000 rpm and a rotating B-axis range of -30° to +210°. Mazak’s unique roller gear cam drive for the B-axis ensures higher accuracy and rigidity, while providing zero backlash. Choice went with the optional 72-tool magazine for ample tooling for continuous part processing. Additionally, the machine incorporates a gantry-style loader for part handling in and out of the work area to extend spindle utilization without human intervention.
To further drive capacity and production, Choice is currently working to incorporate MTConnect for the remote monitoring and tracking of machine tool utilization. Its new Mazak machines are MTConnect capable, and the shop wants to acquire adaptors for its older models so they too can use the protocol.
“Right now we’re experimenting with MTConnect on the INTEGREX i-200S,” said Derek Rothwell, engineering manager at Choice Precision. “We’re just looking at general machine status simply to verify the machine is up and running. Our intent, however, is to run our machines lights out and monitor them remotely using smart phones. This is our first level of MTConnect integration, but we see doing much more with it in the future.”
One could say that Choice is tomorrow’s job shop – as reflected in its use of automation, advanced machine tool technology and getting the most out of what highly skilled labor it has. Aggressive, innovative and always incorporating leading edge manufacturing technology and techniques is exactly what the shop’s major customers want to see it doing.
“Our customers want us to constantly be pushing the envelope,” said Beth Rothwell. “Tomorrow’s successful shops will be those that constantly raise the bar in terms of ingenuity and productivity. This is why we partnered with Mazak – to stay locked in step with the company as it continues to raise its game technologically, and we raise ours. Plus, our customers continue to move forward and innovate, which, in turn, drives the type of advanced technology we need – technology that Mazak continues to develop.”