For many shops, the first step into CNC can be difficult. It's not just the apparent complexity of a computer-controlled machine tool that concerns them, it's also the expense. If you've never been there before, putting down such a large sum of money can seem a very large risk. That's why more shops these days are taking their first step into CNC with low-cost retrofit packages. Moreover, as the retrofits continue to improve, veteran CNC shops are finding them to be a cost-effective way to reclaim manual machines that no longer provide the productivity they need.

A good example of this kind of package is the Slant-8 CNC turning attachment from Scan-O-Matic Inc. (Racine, Wisconsin). Equipped with a tool turret and a two-axis slide, the attachment is designed to convert manual lathes to full CNC capability at low capital outlay. The retrofit can be conducted in the field by the builder's own technicians who provide operational training as well.

The durable Meehanite slides are lined with Tetralon to improve slip-stick performance. Mounting bracketss for the control slide are provided for each individual make and model of machine to which it is to be adapted. The brackets are positioned off the rear way of the lathe and are further supported along the bed casting. An automatic lubrication system is also provided with the slide assembly to deliver lubricants to the ballscrews, slide ways, and bearings. The slides are driven by two Fanuc servomotors capable of delivering 52 inch-pounds of torque through two one-inch diameter ballscrews.

Mounted to the X-axis slide is a bidirectional, eight-position tool turret with an octagon tool disk. The turret is available in three different sizes which appropriately span lathes ranging from 12 to 24 inches of swing. The turrets provide coolant distribution for each station and accommodate shank sizes from 3/4 to 1 1/4 inches.

The retrofit package includes a Fanuc O-TC computer numerical control, designed for shop floor programming. The control is designed to help new users of CNC. Step-by-step prompting guides the operator through the procedures of setup, cycling, programming, editing, and complete machine functions and operations. Also, a manual pulse generator (MPG) is provided for high-efficiency manual positioning of the slide. By rotating the MPG handle, the operator can control each axis independently for tool positioning and setup.

Options for the package include a full enclosure and a coolant delivery system. The seven-gallon capacity system includes a 1/2-hp pump capable of generating 30 psi.

The book on hydraulic toolholders list that they are fussy to set, fragile to operate and expensive to buy So why do many shops choose them over other holders that seemless demanding? This Chicago mold builder has good reasons for its choice.

GM Tool Corporation (Elk Grove, Illinois) manufactures plastic, diecast and compression molds. The company has been a custom mold builder since its inception in 1965. Its customers are involved in the medical, automotive, consumer products, appliance and computer industries.

The company also understands the production side of injection molding because, in addition to a stable of commercial customers, it also has its own molding division--called Sun Plastics. That company has been in business for 15 years.

A big part of the success of a custom mold shop is keeping itself ahead of competition. "That used to mean beating mold shops in the region," says GM Tool's plant manager Ken Moeller. "Today that competition is global."
For GM, the way to compete is to focus on the tough jobs. "The easy work goes overseas or south of the border," he adds. "What's left are jobs that demand the highest skills." So to play in this market, GM Tool, and companies like it, must not only be good metal cutters, they must also be heavily slanted toward engineering.

While Ken Moeller is responsible for the manufacturing side of GM Tool, his nephew Rick Moeller runs the engineering and programming. GM Tool has seen commercial demands and available technology change its approach to the business. The company has evolved an effective business plan that could be relevant to many other shops in increasingly competitive markets.

Taking Out Guess Work

For a custom mold builder such as GM Tool, the competitive edge flows from engineering. "Our shop is run basically with engineering," Rick Moeller says. "Data is crucial to development of the tools we build. Our design engineering is done on a Unigraphics platform. It also generates the tool path for our machines. Engineering and machine programming are critical skill areas for our mold shop."

The output of this strong engineering and programming focus is the ability to, in effect, automate much of the core and cavity machining. Of course, that means carrying the sophistication of the CAD/CAM system to the shopfloor.

DNC is the carrier of this information to the machine tools. GM Tool has been downloading programs to PCs for dissemination on the shop floor for almost 15 years. "We were very early into DNC," says Mr. Moeller.

Making molds is among the most complex metalworking applications. It involves numerous operations including, in GM Tool's case, high speed machining of cores, cavities and graphite electrodes for EDM.

Each of the manufacturing process steps depends on the accuracy of the preceding operation. "We try to look at the process as a continuum," says Mr. Moeller. "At each juncture we look at what is the best technology to bridge to the next step. Of course, as a custom molder, we don't get second chances. It has to work."

While this pressure to make it right the first time is often manifested in shops as conservative practice or a resistance to change from the known, GM Tool approaches the problem differently. To keep moving forward, but at the same time keep risk to a minimum, the company does its homework on a potential new tooling, process, or automation enhancement before it becomes integrated into the shop.

Good Tools Need Goad Toolholdors

To make sure the shop has confidence in its process, rather than letting the process be a limit on capability, GM Tool invests in good quality equipment. The hope is if everything is done correctly upstream, the actual machining of the mold is almost anti-climactic.

About 5 years ago, GM Tool invested in a high speed machining center to improve processing of graphite electrodes for the EDM operations. The company installed an OKK machining center and, because of high speed machining techniques, saw a huge reversal of what was once a bottleneck.

"High speed changed our entire electrode machining process," says Mr. Moeller. "We applied the Erowa modular workholding system to further automate this part of the mold making process. It has eliminated our need for manual EDM machines. All of our equipment is CNC with orbiting capability and other features to get the finishes demanded by our customers.

"Before getting into high speed graphite milling, we basically machined electrodes by hand or using laminates," continues Mr. Moeller. "The tool path for machining electrodes is downloaded directly from engineering. Now the operator has time during the machining cycle to perform other tasks. We have much more unattended machining time available with our high speed graphite milling operation."

High speed machining techniques are also applied to core and cavity production. The company has a Makino V55 for semi-finishing and finishing operations. Like the graphite milling system, automation of the metalcutting process frees up the operator for additional tasks.

Constructed with solid granite machining table, miniRaptor(TM) utilizes 60,000 rpm spindle with 0.125 in. collet, has 51 x 51 in. footprint, and provides 20 x 20 x 8 in. working envelope with room for fixturing and batch machining of small parts. Unit incorporates 3-Tool Automatic Tool Management System(TM), and Windows[R]-based control software. Along with 15 in. monitor, unit offers Ethernet networking capability and Ethanol-Mist Coolant System(TM).

MILFORD, NH, Apr. 11, 2005 - For the first time, Datron Dynamics, Inc. will be exhibiting a compact version of their high-end Raptor Class machining center at EASTEC. 2005, booth 3347. In the development of the miniRaptor(TM), Datron has utilized the same technology pioneered for their larger machines while minimizing size in order to offer entry-level pricing. Although the 51" x 51" footprint makes the miniRaptor(TM) Datron's most compact machine, it still features a 20" x 20" x 8" working envelope with ample room for fixturing and batch machining of small parts. The smaller bed size has facilitated the use of a solid slab of granite for the machining table that provides manufacturers with increased rigidity to minimize vibration.

The miniRaptor(TM) leverages the unique features of the Raptor Class and makes them available at an affordable price to provide smaller manufacturers an entry to high-speed, micro machining. A no-haggle, Datron-direct, package price offers standard features including a 60,000 RPM spindle with a 0.125" collet, a 3-Tool Automatic Tool Management System(TM), Microsoft Windows[R]-based control software, a PC with 256 MB RAM and 40 GB part/program storage, CD-ROM drive, 3.5" drive, USB port, 15" monitor, keyboard, hand-held controller, Ethernet networking capability, remote monitoring capability, a removable chip disposal tray and a full machining-area enclosure with an industrial-grade door safety interlock system.

The miniRaptor's 60,000 RPM spindle produces low force and superior quality when tooling 0.125" and under. An integrated Ethanol-Mist Coolant System(TM) provides for superb surface finishes and eliminates secondary processes like de-burring or de-greasing to further improve cycle times. Datron's Microsoft[R] Windows[R]-based controller works with virtually any CAD/CAM software and offers Ethernet networking capability, as well as remote monitoring and control, allowing the machine to seamlessly integrate into any manufacturing environment.

This comprehensive package of standard features can be augmented or added to with a number of available options including a 600W, 60,000 RPM spindle with 0.250" collet, a 10-Tool Automatic Tool Management System(TM), a flat screen LED monitor, a Z-Correction Probe(TM) that recognizes irregular work piece topology and a 3D probe extension that locates and compensates for material irregularities in X, Y, and Z coordinates and facilitates reverse engineering.

About Datron: Datron Dynamics is the North American distributor for Datron Electronic, a German technology firm established in 1969 that has become a leader in the design and development of CNC machining and dispensing systems. Founded in 1996 by President, Walter Schnecker, Ph.D. and Vice President, William King, Datron Dynamics is differentiated in the marketplace by its focus on high-speed machining with micro-tooling. Datron machines feature 60,000 RPM spindles that produce low force, feed rates of up to 1000"/minute and superior quality when tooling 0.250" and under. An Ethanol-Mist Coolant System(TM) provides superb surface finishes and eliminates secondary processes like de-burring and de-greasing while being environmentally friendly. Other features such as the Z-Correction Probe(TM), Automatic Tool Management System(TM) and their proprietary Quick-Pallets(TM) and Vacumate(TM) workholding systems enable batch machining and "lights-out" production. These distinctions have resulted in thousands of installations worldwide within industries requiring versatility and efficiency with small tools for front panels, nameplates, micro drilling, 3D precision engraving, aluminum machining, rapid prototyping, as well as the production of automotive and aerospace parts.

The GibbsCAM Multitask Machining (MTM) option supports machine tools with multiple spindles and turrets or tool groups. The software addresses synchronizing multiple tools through its Sync Manager, an element in the intuitive, graphical user interface environment. The Sync Manager allows multiple process flows to be displayed relative to one another to facilitate setting synchronization points. The Sync Manager also takes into account dominant tooling and automatically adjusts operation durations based on which tooling controls the spindle speed, another level of detail that programmers would normally have to address. To be able to support this range of machine tools, which includes models such as Mazak Integrex 200 III ST and Mori Seiki MT 1000SZ, 2000SZ and 2500SZ, MTM was designed with machine configuration capability. The company says it ensures that when the software is delivered to the customer, it is completely set up for its machine tool from the machine configuration to the post processor used to generate edit-free, machine-specific NC code.

Earlier this year, Iscar, the cutting tool manufacturer (U.S. headquarters in Arlington, Texas), brought together its North American dealers and many customers for a seminar called "Iscar Upgrade." At this event, the company announced its product development plans for 2005-2006. As top company executives led presentations detailing these developments, they expressed a number of general insights about cutting tool philosophy. A sample of these observations is presented here for anyone with an open mind about cutting tools.

1. The Costs That Count

Typically, cutting tools account for only 3 percent of total production costs in metalworking. Therefore, reducing cutting tool costs in itself doesn't bring much to the bottom line. However, upgrading cutting tools is likely to yield a significant overall cost savings, even though cutting tool costs may be higher. Focus on cost per part, not the cost of cutting tools, as a key target.

2. Cutting Tools Are A System

Everyone in your IT department knows that a successful computer system is a combination of the right hardware and software. Keeping both hardware and software up to date is critical. Think of cutting tools in the same way. Cutter bodies and toolholders are the hardware, and indexable inserts are the software. When looking at an upgrade in insert technology, be sure to consider upgrades in toolholders and cutter bodies, and vice versa.

3. Coatings Aren't Just For Inserts

Cutter bodies can be coated to get some of the most important benefits that high-tech coatings bring to carbide inserts. Hard coatings on cutter bodies resist wear from contact with hot chips moving at high speeds. Chips flow more readily through flutes because the coating gives the surface lubricity.

4. Multifunction Tools For Multitasking Machines

Few developments in machine design have had the impact that multitasking machines have had on productivity. But those added spindles, tool turrets and rotational axes mean tight clearances and a limited number of tool stations. To cope with these conditions, it is possible to have one toolholder with several multipurpose inserts that can do facing, ID turning, OD turning, drilling, counter drilling and internal threading without a tool change. Creative application of specially designed cutting tools contributes significantly to the flexible nature of multitasking machine tools.

5. Modular Thinking Is Lean Thinking

To keep cutting tool inventory at a more manageable level, consider modular tooling shanks that accept a variety of interchangeable solid carbide heads. Because the heads can be replaced or exchanged while the tool is clamped in the machine, setup time can be reduced. A set of long shanks that allow a cutting tool to reach to the bottom of a deep pocket or mold cavity is especially economical compared to the assortment of solid carbide tools needed to cover the same range. Another plus is that a steel shank can absorb an impact that might otherwise damage a carbide shank when, for example, a turning tool and the lathe spindle are not perfectly on center.

6. Don't Neglect Power Consumption

Cutting tool manufacturers are working hard to develop products that reduce the power consumed by machine tools. Besides the energy savings (which are more significant than ever), cutting tools that require less power from the machine tool tend to last longer, cause less wear and tear on spindles and ways, and minimize vibration. A good example is that cutting tools requiring less thrust are allowing longer boring bars to be used without losing accuracy.

If power consumption doesn't come up in the discussion of any new cutting tool, be sure to ask about it. A 10 percent reduction in cutting forces is likely to result in a 50 percent improvement in tool life.

7. Get Clamping Forces Right

When tightening the clamping screws after indexing an insert, don't guess about the torque applied. Undertightening may allow the insert to chatter or prevent the process from holding tolerances. Overtightening may break the insert or the key. A torque wrench that automatically lights up to signal that proper tightening levels have been reached is a simple way to eliminate this uncertainty.

8. Can Your CAM Software Keep Up?

Programming for CNC operations is about more than getting the right speeds and feeds. Tool paths also must match the capability of the cutting tool. Not all CAM software allows the programmer to program the moves that optimize the performance of advanced cutting tools. Be sure your programming software is not holding you back.

Right now, advances in cutting tools appear to be ahead of the software developers.

9. No Vibes Are Good Vibes

In real estate, the three most important factors determining the value of a house or commercial property are location, location and location. In successful cutting tool applications, it's vibration, vibration and vibration. Minimizing or eliminating vibration is usually a matter of controlling cutting forces so that they are directed to the most stable, most rigid element of the machining system. Examine every proposed change in tooling with an eye to how vibration is managed. That's the key to prolonging tool life, protecting the spindle and improving surface finish.

A bar puller kit has been designed for gang tool-style CNC lathes. Because of the limited space between toolholders on gang tool plates, interference between tool shanks can result in the loss of one or two tool positions. The bar pull kit accommodates the shanks that require a minimum amount of lateral space (5/8" shank diameter, 0.84" shoulder diameter).

The bar pull kit includes 10 grippers for barstock diameters from 3/16" to 3/4" (in 1/16" increments). These grippers mount directly to the 5/8" diameter bar puller shank. According to the company, the lightweight and self-activating bar pull has no moving parts and does not interfere with other tools. The bar puller requires only 1/4" of barstock engagement and pun-positions the barstock to within 0.001".

For its 26 machining centers alone, PHD's Huntington, Indiana manufacturing facility has 4,875 tools in its active library. And "active" is the operative word. The rate at which tools are swapped in and out of machining centers is increasing. Last year, the plant did 63,717 tool setups. This year, it will do more than 79,000. No matter how you look at it, this plant uses a lot of tools.

Yet just one tool presetter measures all of the relevant data for all of the tool setups for these 26 machines. The software associated with the presetter manages lathe tooling as well. Two employees, one for machining centers and one for lathes, serve as the gatekeepers who maintain the integrity of this information. In short, while the plant uses a lot of tooling, it has a tightly controlled and centralized system for keeping that tooling in order.

PHD started building this system about a decade ago. At that time, it wasn't clear just how important the system would become. The company's business is changing. This maker of automation components--including cylinders, grippers, slides and rotary actuators--is seeing lot sizes and leadtimes shrink, while the number of product designs proliferates. In greater numbers, customers are asking for just-in-time service at the same time that they ask for custom products in place of catalog items. These changes are good, because PHD feels particularly capable of meeting these demands. However, the response to the demands is effectively transforming the Huntington production plant, along with a sister plant in Fort Wayne, into something more like a job shop.

However, the difficulty is that PHD lacks many of a job shop's options. In a job shop, a smaller number of machining centers might have substantial tool capacity in each machine. The shop might equip these machines with a standard complement of general-purpose tools that could be applied to almost any job coming in the door. In other words, a job shop wouldn't have to swap out tools so much.

PHD can't afford these kinds of concessions. It can't afford to devote that much floorspace to tool magazines, and it can't afford to hold that much tool inventory in every machine. Nor can it afford the cycle-time compromises that come from using general-purpose tooling instead of tools specifically suited to specific details of the part. What this plant needs is a system controlled and responsive enough to handle a large volume and variety of tooling. The plant had the foresight to begin putting such a system in place in 1994.

Over the years, the system has reduced human error, reduced the plant's overall scrap rate and improved the change-over time between jobs. Today, this system is facing a challenge, but it's not a challenge related to effectiveness. The challenge has more to do with physical limits. Part of the system's elegance lies in the fact that one presetter can serve so many machines, but the plant is now running this presetter around the clock. At 79,000 tool setups, the plant is pushing the upper limit of how many tools per year a presetter can measure.

The first presetter that the plant installed, like the plant's current model, came from Zoller, Inc. (Ann Arbor, Michigan). Even though the model PHD was using in 1994 was quite possibly the most sophisticated presetter installed in the United States at the time, the technology has improved significantly since then. The plant still has this first model sitting in a corner, because the plant can't find a buyer for it. The current model, purchased 4 years ago, beats it handily in terms of both precision and ease of use.

At least a year went by before presetting was integrated into the plant's process in something like the way it is today. The presetter itself is only part of a package that also includes tool management software--a vital element for using the presetter well. Tooling technicians at this plant used that first year to populate this software with the shop's preferred tools. They assigned tool names and ID numbers, associated toolholders with the tools, and input nominal dimensions and cutting parameters for the plant's various workpiece materials. All of this information had to be entered one tool at a time, in spare moments as PHD's production continued. Only after a year was there enough information in the system that a sizeable proportion of the plant's tools could be called up from memory instead of being entered for the first time. The tool crib personnel called up tools in this way, but just as importantly, so did the programmers. Their ability to select from a common reserve of tooling saved them time and guesswork, and it made the process more consistent by ensuring that standard tools were used in standard ways. At about this same time, the presetter itself was connected to the shopfloor network.

There was resistance from the shop floor then, and understandably so. Operators had long been accustomed to keying in their own tool offsets, and in many cases, even measuring their own tools. Now they were being asked to hit "cycle start" on programs using tool data they had never even touched.

Culture shock is one of the biggest obstacles to implementing lean manufacturing into an existing shop. Getting experienced shop workers to adopt a lean waste-ridding mindset often isn't the easiest thing to do. R&D Manufacturing Industries, Inc., located in Ocala, Florida, didn't have to jump that hurdle because it was lean right out of the blocks.

The combined work experience of the shop's principals melds into an interesting blend of business acumen and machine shop experience. Ron Malone, company president, has amassed a wealth of lean manufacturing knowledge during 10 years in the automotive supply industry. He's also an engineer and attorney. His partner, Dennis Miller, is a 30-plus-year tool and die veteran.

How the two first met is also interesting. Before joining forces in January 2004, they competed together at Shriners of North America motorcycle events on their Harley Davidson motorcycles. (Machine tools are neat, but the two gleaming white "Hogs" parked at the shop were what first caught my eye during my visit.)

When founding the shop, the partners' business plan was to apply only those lean tools appropriate for their situation, not hap-hazardly shotgunning lean techniques that may or may not prove fruitful in eliminating waste in a contract shop. Mr. Malone knew that visualization, which is essential for the success of any lean manufacturing program, would play a key role in the set up of the new shop. "An employee should be able to walk through a work area one time and come away with 90 percent of the information about that area after that first tour," Mr. Malone explains. Not only does this streamline experienced workers' day-to-day duties and improve their productivity, but it also helps new hires to ramp up quickly. Visual management tools, including 5S organization, allow such quick information access.

It's common knowledge what a picture is worth. The following pictures illustrate a few of the ways that visualization was incorporated in this lean shop from day one.

1. Visualize Shop Layout--To control up-front costs, R&D chose a modest 3,000-square-foot building that offered additional space as the company grew. The compact floor space was a blank slate, and the two partners spent a great deal of time designing a layout of equipment that would promote economy of motion and unrestrictive flow of parts and persons.

The shop's first two CNC machines were a Puma 240 lathe from Daewoo (West Caldwell, New Jersey) and a RWI4 VMC from Milltronics (Waconia, Minnesota) that were positioned closely together in an E-shaped cell. About a year later, a Daewoo DMV 4020 VMC was added to form the current U-shaped cell. Close machine proximity minimizes worker motion to allow tending of multiple machines. Typically two workers, but sometimes only one, will tend the entire cell. A second CNC lathe, the shop's and possibly South Florida's largest, was purchased with the prospect of winning a tough turning job (see sidebar on page 70). Though this Daewoo Puma 300L machine is dedicated to large-part production, and is not part of the three-machine cell, its position near the cell allows it to be operated by the U-cell associates.

Worktable size was also kept to a minimum, as large horizontal spaces tend to attract unnecessary clutter to a work area. Even the shop's material rack is small, because the company orders material very close to the time that a machining job will start so as not to have money and space tied up before the material is needed. R&D maintains a close relationship with its material suppliers and other vendors to ensure that they will do whatever it takes to deliver services on time.

Work areas that are compact, but not cramped, not only promote efficient motion, but also improve scheduling accuracy by allowing a more precisely predictable determination of a job's total cycle time. This total cycle time is not just the time a machine is producing chips; it takes into account all factors involved in part production, such as setups, inspection, secondary operations and so on. This is especially important when maintaining a supermarket of parts for a customer. As Mr. Malone explains, the prime reason that supermarkets fail are because the supermarket is sized incorrectly. The trick to formulating the appropriate supermarket size is to know the shop's total cycle time and customer's takt time (based on the number of parts that the customer is pulling on a regular basis).

2.5S Organization--This idea of a more predictable motion is also a function of 5S organizational principles, which are direct extensions of the visual factory theme and staples of any lean push. Just what the 5S's stand for can differ from shop to shop (they typically represent sort, shine, simplify, standardize and sustain). For R&D, the 5S concept means having tools where they're needed when they're needed. A couple of examples are having a tape measure sitting by the saw rack, instead of in a toolbox, or using a magnet to hold a straight edge on a machine tool's enclosure, rather than sitting on a worktable. In order to minimize wasted motion, R&D will sometimes purchase extra hand tools and spread them out in key areas of the shop.