Grinding shop steps up to CNC machining

Rob Murnyack had been turning his professional life upside down in a quest to use CNC machining at his shop. He'd been working for his father for more than 20 years in what had become a successful grinding operation. However, Mr. Murnyack wanted to take the company to the next level--using CNC machining.

"We couldn't gather a powerful enough argument to nudge my father over the line," Mr. Murnyack says. "I can't blame him. He's 65 and has built a solid business around manual operations, and for him to invest $150,000 to $200,000 to move in a new direction was a tough sell."

Mr. Murnyack worked out a deal with his father, setting up a kind of "beta site" operation. He took several of his father's employees, a number of established customers and four manual grinding machines and began Absolute Grinding (Mentor, Ohio) in May 1994. Then, 4 months later, he found himself in Chicago, Illinois at the International Manufacturing Technology Show (IMTS).

"I wasn't making a salary at this point," he says. "Here I was looking at machines that cost $200,000 and more. I thought I was nuts. But at the same time, I realized I needed to make the investment if I wanted to shift gears to CNC."
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Obviously, a lot rode on his first plunge into CNC machining. He chose a Studer S35cnc universal cylindrical grinding machine from United Grinding Technologies (Miamisburg, Ohio). It had a choice of a straight or angular infeed with the grinding wheel mounted left or right; wheel dressing and profiling with continuous path control; automatic grinding and dressing cycles; automatic change-over from external to internal grinding; and an automatic swiveling wheelhead. It also allows the use of up to three grinding wheels in a single workpiece program, as well as a special workhead with a C axis that permits form and thread grinding.

Mr. Murnyack notes that none of his employees were familiar with CNC, so in that respect, the new machine had to be easy to learn. "We literally self-taught ourselves," he says. "The programming was that easy."

Three years after he entered the CNC arena, Mr. Murnyack added an S36cnc, a universal cylindrical grinding machine for medium-sized workpieces. His objective was to find a quality machine that could do internal and external grinding for less than $250,000.

One of the bonuses of the grinding machine, according to Mr. Murnyack, was that it allowed the company to do random wheel shapes and more intricate configurations of the grinding wheel and of the grinding cycle. In general, it gave Absolute the ability to tackle complicated projects.

The latest addition to the company's fleet of Studers is the S31 cnc purchased in 2001. Mr. Murnyack thought he should investigate the new generation of CNC machines, which are more flexible than their predecessors and would allow the company to handle a wider variety of parts with a reduction in setup time. The S31 took care of this, with a drive-spindle power of 10 hp, grinding wheels with a maximum diameter of 20 inches, a width of 3.15 inches and an infinite B axis. It permits grinding ID, OD and tapered ID's on one machine.

"We do four or five setups a day," he explains. "This is a job shop. We can't spend 4 hours on a setup. My guys can switch from an ID operation to an OD operation on a different part in an hour with the S31. With other machines, I hear from people in the field that they might spend 4 hours just writing the program. It takes us just 5 minutes to write these programs on the CNC machines."

Because of the significant time savings the company has discovered when using CNC machines, Mr. Murnyack and his shop employees understand what a difference they can make in a shop's efficiency. Not only are these machines easy to operate, but they also provide quality machining to complicated projects. They also allow one machine to perform many tasks, rather than wasting time using several machines.

Orscheln's Screw Machine Division Installs Two New CNC Lathes

Orscheln's Screw Machine Division (formerly known as Qualico Precision Products), Moberly, Missouri has recently installed two new CNC lathes.

This Orscheln location offers screw machine products, plating and coatings and is a QS9000 registered company.

The two new lathes, EmcoTurn 420MC plus models, feature two spindles with two sub-spindles and auto bar-feeders.

"These lathes represent the newest technology available," stated Orscheln's Plant Superintendent Daryl Duchesne. "They will replace several manual screw machines as well as secondary equipment since they produce finished parts. This will improve our efficiency and help lower our costs, especially on machining-intensive parts."

The company has 35 other screw machines (single and multispindle) and various secondary equipment. It specializes in high volume, long run, precision screw machine components, but is capable of low volume orders as well.

The screw machine operation works with steel, brass, aluminum, copper, stainless steel and plastics up to 1.25" diameter in round, hex, tube and square stock.
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Over 20 variations of plating are offered at Orscheln. Its plating lines utilize barrels 36" in length and 16" in diameter.

Coatings offered include dipspin Magni-Coating, Elisha's EMC (Electrolitic Mineral Coat) process and powder coating.

The company serves a diverse range of customers in such industries as: automotive, off-highway, furniture, computer, marine, aircraft, military, lawn & garden, heavy truck, recreation, construction and agriculture.

Efficient CNC flexible system transfer saves time and money

Since its organization in 1994, American Axle & Manufacturing (AAM) (Detroit, Michigan) has been proving to the industry that a U.S. manufacturer can be competitive on cost and quality. The company attributes its success to its investment in manufacturing technology and training.

To meet quality and volume requirements from a customer who hoped to increase the torque and load-bearing capabilities of its full-size pickup trucks and SUVs, AAM engineers developed a process to produce a new rear differential gear carrier. It was the largest the company had ever produced, at 118 pounds.

The process initially used a series of large horizontal machining centers (HMCs) to meet the demand for the 11.5-inch carrier. Then, using the same process, fixtures and tooling, AAM ramped up using a CNC Flexible System Transfer (FST) line from Heller Machine Tools (Troy, Michigan) when volumes went from 35,000 to 240,000 parts annually. The process and the equipment permitted the plant to respond quickly and cost-effectively to the change in demand while consistently achieving quality goals.

In developing the carrier design, AAM paid special attention to details that would positively affect the part's perceived noise, vibration or harshness characteristics, and would thereby provide an advantage to customers in the pickup truck and SUV market.
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Once the parts were designed, the company conducted simultaneous engineering programs with three machine tool companies to evaluate each vendor's approach to its manufacturing challenge. In each case, AAM was interested in flexible manufacturing cells to handle relatively low initial production volumes. The company also looked for machine tool vendors that used Hirth couplings on their rotary tables, which AAM felt would help it meet critical tolerances. The purpose was to prove that the critical dimensions could be consistent on a machining center.

Carrier housings and differential case housings are two important axle components, which AAM machines and supplies to its customers. These parts have been produced by a number of different machining processes: for example, carrier housings were machined on single-spindle horizontal machining centers and dedicated transfer lines, as well as CNC lilt-and-carry transfer lines. The differential case housing was produced on single-spindle HMCs and lathes.

Rather than using 11 to 12 HMCs to produce the housings, AAM invested in a single Heller EST. In the experience of its Three Rivers facility, the FST has proven to be a reliable high production system and to be more cost-effective than HMCs. According to AAM, the FST has the benefits of using less floor space (in this case, about 30 percent less) and has capital costs of up to 25 percent less than conventional transfer lines.

The facility uses the 14-station FST to machine the 11.5-inch carrier housings. These operations include face milling, drilling pan holes, and machining pads for end-cap seating and rough-boring the axle tube bores. The FST then completes the boring process, maintaining the perpendicularity of bores in the carrier. Each bore is completed in three passes. Once the part is finished, it is unloaded and put on a conveyor to a robot-loaded machining center cell, where the remaining holes are drilled and tapped in the carriers. Empty fixtures in the FST are returned via an overhead conveyor to a washer and then back to the load station.

Six Heller MCP-H250 HMCs are also incorporated at Three Rivers. All the machines have HSK 100 spindles, making it possible to use the same tooling in both types of machines when necessary. A hydraulic workholding system uses swivel pads and locator points on the casting to ensure repeatable clamping. The HMCs are also capable of being retooled and refixtured for other components or to supplement production of the FST.

The FST concept uses predesigned modular units mounted on standardized bases with independently controlled stations. Three basic pre-engineered machine sizes cover component dimension, power and technology applications. System components can be combined to create the system best suited to the application. Because all interfaces between the units are standardized, engineering time is reduced and assembly is accomplished quickly, the company says.

The FST was fully assembled and run off on the Heller assembly floor in Troy prior to the delivery to the company. This allowed the FST to be fully operational and on the plant floor in a third less time than a transfer line usually demands.

CNC grinding machine

The company has released its OpenCNC grinder for CNC ID, OD and centerless grinders. The grinder consists of hardware, software and documentation and has been engineered to meet the needs of machine builders, integrators, end-users and retrofitters who specialize in CNC grinding machines, the company says.

The grinder maintains the flexibility and power of open architecture, while providing ease of use and built-in features of a standard package, the company says. It is said to allow machine builders and end-users to easily upgrade or interchange machine hardware, software and peripheral components without having to re-engineer their existing machine logic.

The part programming features include: 11 wheel dressing routines, eight grinding sequences, advanced grinding wheel offset tools and an online help system. Each part program can contain as many as 20 grinding sequences.

The hardware/software package comes with wiring diagrams, documentation and pro-written PLC logic that allows machine builders or integrators to complete a control retrofit without having to spend weeks writing and debugging special machine logic, the company says.

CNC features important for lathes used on oil valves

Kimray, Inc. (Oklahoma City, Oklahoma), a manufacturer of control valves and related equipment for oil-and gas-producing companies, reports a 40 to 50 percent increase in its machining efficiency, achieved largely as the result of CNC-based production equipment. Control features that simplify programming and setup on the company's latest CNC lathes contribute to this productivity trend.

Founded in 1948, Kimray operates a 125,000 square-foot facility and employs more than 250 people to serve its expanding customer base. The company machines iron, steel, aluminum and thermoplastic materials to build its line of control valves, thermostats, energy-exchange glycol pumps, gas-operated pilots and other control devices. Its products are used to control vessel and lead line temperatures, the liquid level inside pressurized vessels, pressure drops and liquid/gas flow.

The company maintains a turnkey manufacturing facility that includes dozens of lathes, grinders, turning, milling, sawing and bore finishing honing machine tools, almost all with CNC systems on board. The newest arrivals are Emco Maier Emcoturn 420 MC Pills and Hyperturn 665 MC Plus lathes, each equipped with Sinumerik 840D CNCs and Simodrive 611D drive packages from Siemens (Elk Grove Village, Illinois). Kimray operates a host system for file storage and backup on all part production data.
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The company has been especially pleased with the CNCs. One operator explains that with the Sinumerik 840D, programming and cut and paste operations are possible even while the machine is running.

"Each screen allows you to be very detailed about what you're doing, such as separating your mains from your subs with your part and workpiece programs,' he says. "I use the Siemens CNC for axis and spindle movements on both machines. My programs and data can be accessed easily and transferred back to the machines [from the company's main host system] as needed."

He can run operations, such as milling and stenciling, out of the sub programs, he adds. "I use the parts program as my way to transfer files and folders to the main system and back again."

He commented further on the controls. "On a typical setup, I like the sensitivity. Being able to move the axis only a ten thousandth at a time to a hundred thousandth at a time comes in bandy. I also like the program test feature, especially on new programs. Each tool has its own geometry page and up to four offsets, making things less complicated."

Kimray typically machines barstock of 303, 304, 310, 316 and 17-4 stainless steel, as well as D-2 tool steel, 6061-T6 aluminum, brass and Teflon. Cast iron, ductile, steel, stainless steel and aluminum are also machined by the company.

The 665 Hyperturn machine enables four-axis machining plus full C-axis capability on both the main and counter spindles. The 665 uses some of the same programming features, plus the same digital drive systems as the 420, but in a larger package.

CNC machine for turning, drilling, milling and grinding - Modern Equipment Review

The company recently introduced the Hardpoint 300, a CNC machine that combines turning, drilling, milling and grinding. It is a modular concept machine and can be configured with up to four main spindles and a variety of tooling combinations, depending on user needs. The machine can machine the front and rear faces of a single part; machine a single face on two parts simultaneously; machine the front and rear faces of two parts simultaneously; or machine a single face on four parts simultaneously.

The company says its product represents a flexible and economic machine concept for high-quality, complete machining of small components. The axes is variable, with up to ten possible. The machine offers fully automatic, synchronous complete cutting of complex workpiece geometries, up to a diameter of approximately 3" x 3" (80 mm x 80 mm).

The modular machine concept is said to ensure machining efficiency and flexibility. The various platforms are said to allow several cutting processes to be combined, thereby eliminating the need to operate multiple machines. The company says this reduces floor space requirements and operation costs. The machine incorporates an internal gantry loader. External loaders are also available as is a post-process measuring system.

Steering to greater flexibility: re-tool aging dedicated machines? For this plant, it makes more sense to spend a bit more to replace them with new, m

Sure, a dedicated machine delivers faster cycle times, but when it goes down, production stops until the machine is repaired. And for what it costs to re-tool that dedicated machine for another job, you can almost buy a new, more flexible, CNC machine that is better suited to today's production requirements." If you get the feeling from the above remarks that dedicated machine tools are on the way out at Visteon's Chassis plant in Indianapolis, Indiana, you're right.

The plant, which specializes in the production of power rack and pinion steering gear assemblies for passenger cars and trucks, has eliminated about half of the dial index machines used to produce input shafts, a critical component of a power steering valve. And as the input shaft jobs running on the remaining dial index machines end or change, the plant expects to retire them, rather than re-tool them, as well.

The input shaft is a cylindrical steel component, about 6 inches long by 1 inch in diameter, machined from barstock. It requires numerous operations, including an "Op 80," in which multiple holes (hydraulic fluid passages) are drilled through the OD to a main bore running the length of the part.
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At one time, the input valves were drilled almost exclusively on automatic dial index machines. Recently, however, the Visteon plant received an order for a new rack and pinion steering gear assembly with an input shaft that required an unusually small (1.5-mm diameter) hole. At a staff meeting to discuss the new job, the drill supplier advised that the small hole would have to be drilled at a higher rpm than the dial index machines were capable of, so the staff began considering alternate ways of producing the hole.

"We have a large number of dedicated machines in the plant, and there was a growing awareness that the time and cost involved in setting up the machines for different jobs greatly limited our efficiency and flexibility," explains Wahid Kapadia, a member of the Forward Models Engineering department. "We started looking for a CNC machine to drill the small hole for a number of reasons. First, many CNC machines offer the spindle speeds that we needed to drill the hole. Second, small drills are vulnerable to breakage, and CNC machines offer the tool control needed to minimize the problem.

"Third, we are very concerned about maintaining production rates," be continues. "When a problem arises on a dedicated machine, production stops and does not start again until the problem is solved. On the other hand, when production is spread over several standard CNC machine tools, if one machine develops a problem, the other machines continue to make parts, and although production is affected, it isn't completely stopped."

The plant first considered a CNC lathe with live tooling. However, it was unable to find a machine that offered the drilling speed required for the small hole.

Next, the plant looked at standard CNC drilling and tapping machines. Several such machines would be needed to satisfy the production volumes involved. However, because the machines would run in a largely unattended mode, some add-ons would be required to equip them for the job. One or more robots would be needed to automate the loading-unloading of parts. An indexing workholder would also be needed to index the input shaft in 90-degree increments for drilling. The prospect of buying the machines and fitting them with the workhandling equipment needed for the job was becoming daunting. A simpler solution was desired.

After more research, the plant investigated the A-Series machining centers made by Wasino Corp. U.S.A. (Rolling Meadows, Illinois). The A-Series consists of four-axis (X, Y, Z and C) machining centers with secondary turning capability. Configured more like automated turning machines than conventional machining centers, the series has a horizontal, 4,000-rpm spindle with a C axis that is programmable in 0.0001 inch increments. The spindle is served by a tool turret, which can accommodate a rotary or turning tool at each tool station.

The A-Series machines also feature an integral gantry loader that takes parts to be machined from, and returns machined parts to, a compact, carousel-like staging area at the rear of the machine. The machines come with chucks up to 10 inches (for the largest model) for handling discrete parts, as well as a spindle bore that permits feeding barstock or extrusions to the machine from a bar feeder.

One of the most important features of the machine to Visteon was that the tool turret could directly drive (with no gearing) rotary tools to speeds up to 10,000 rpm, providing the speed to drill the small hole needed for the new input shaft. Accordingly, the plant purchased the A-12 model (for 12 turret tools). To make certain that the plant would have adequate drilling speed for current and future jobs, it purchased the machine with a speeder head that doubled the maximum speed capability to 20,000 rpm

CNC multispindle - Spotlight: workholding

The company has recently introduced the MultiDeco 20/8b. This machine is configured for machining parts up to 20 mm in diameter. It has eight spindles and comes equipped with an integrated bar feeder. The machine is also available in a 2 x 4 configuration. This model can be a traditional eight-spindle machine, or a two four-spindle machine to produce two relatively simple, separate parts at the same time. The model is said to combine the advantages of cam-controlled and CNC machines through the use of TB-DECO software and its PNC control.

As an eight-spindle machine, this model can produce highly complex parts featuring cross milling/drilling with 23 simultaneous axes, six cross slides and spindle and counter-spindle stops, the company says. The counter spindle has two axes capability, permitting complete machining of a part. The machine features different spindle combinations, including single-speed, two-speed and two-speed with stopping.

Rapid Planning for CNC Milling-A New Approach for Rapid Prototyping

This paper presents a description of how CNC milling can be used to rapidly machine a variety of parts with minimal human intervention for process planning. The methodology presented uses a layer-based approach (like traditional rapid prototyping) for the rapid, semi-automatic machining of common manufactured part geometries in a variety of materials. Parts are machined using a plurality of 2 ½-D toolpaths from orientations about a rotary axis. Process parameters such as the number of orientations, tool containment boundaries, and tool geometry are derived from CAD slice data. In addition, automated fixturing is accomplished through the use of sacrificial support structures added to the CAD geometry. The paper begins by describing the machining methodology and then presents a number of critical issues needed to make the process automatic and efficient. Example parts machined using this methodology are then presented and discussed.

Keywords: CNC Machining, Rapid Manufacturing, Rapid Prototyping, Process Planning, Computer-Aided Manufacturing
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Introduction

The cost of producing small numbers of parts has been driven by the cost required to process-engineer the part(s). Traditional computer-aided process planning (CAPP) systems have reduced the time required to plan machined parts, but the cost for one or two-of-a-kind machined parts is still dominated by the cost of planning the part. The current use of CNC machining for these small quantities of parts is further limited by special tooling costs and machine setup.

The typical approach to planning parts for CNC machining has been to define the "features" of the part and match these features and tolerances to a set of processes that can create the required geometry to the specified accuracy. This approach has worked reasonably well for medium to high-volume parts, but it has had marginal success for the production of very small quantities of parts. In most cases, the time required to plan the part, kit the required tooling, and set up the machine (both fixture and tooling) has limited the use of CNC for these applications. The result is that rapid deployment of CNC machining has been relegated to a simple set of part geometries. The promise of minimal process engineering is a major factor that has driven the use of freeform rapid prototyping (RP) techniques. Unfortunately, many of these processes have been restricted to a small variety of materials with limited geometric accuracy.

In the literature, process planning is often approached with a set of goals driven by high production levels of parts-that is, a set of plans that strives for cost effectiveness through maximizing feeds and speeds and creating repeatable setups that can be paid for through economies of scale. Process planning for CNC machining includes tasks such as fixture planning, toolpath planning, and tool selection. There is a considerable amount of work in the literature pertaining to these three areas (Maropoulos 1995; Chen, Lee, and Fang 1998; Joneja and Chang 1999). The concept of flexible fixturing has been the topic of much research, though a completely autonomous fixture design system has yet to be developed (Bi and Zhang 2001).

Some exploration into the use of CNC machines for rapid prototyping has been published. Chen and Song (2001) describe layer-based robot machining for rapid prototyping using machined layers that are laminated during the process. The process is demonstrated using laminated slabs of plastic, machined as individual layers upon gluing to previous layers.

A hybrid approach using both deposition and machining called shape deposition manufacturing (SDM) continues to be developed (Merz et al. 1994). For each layer, both support and build material is deposited and machined in a combined additive and subtractive process. Sarma and Wright (1997) presented Reference Free Part Encapsulation (RFPE) as a new approach to using phase-change fixturing for machining. The approach was discussed recently in conjunction with high-speed machining (HisRP) (Shin et al. 2002). RFPE, in combination with feature-based CAD/CAM was proposed as an RP system (Choi et al. 2001).

Another approach is to use CNC machining for prototyping dies, an area called rapid tooling (Radstok 1999). One approach to rapid tooling uses machined metal laminates stacked to form dies (Vouzelaud, Bagchi, and Sferro 1992; Walczyk and Hardt 1998).

Many of these methods utilize CNC machining but do not address the fundamental problems of automating a fully subtractive rapid machining approach. This paper presents a method for "feature-free" CNC machining that requires little or no human-provided process engineering. The methodology described in this paper is a purely subtractive process that can be applied to any material that can be machined. The method described herein was developed in response to the challenge of automating as much of the process engineering as possible. The ultimate goal is to generate both the NC code and an automatically executed fixturing system by the touch of a button, using only a CAD model and material data as input. The process is perfectly suited for prototypes as well as parts that are to be produced in small quantities (~1 to 10)

CNC Grinding Machine optimizes CBN in shaft production

Designed for volume production of round and non-round shaft parts, Zeus M has grinding length to 950 mm, max diameter of 430 mm, and center height of 220 mm. Product handles workpieces up to 80 kg and combines cylindrical, non-round, plunge, and high-speed peel grinding (HSP) in one machine. It employs polymer Granitan machine bed, galvanic-bond and ceramic-bond CBN grinding wheels, and 130 mm rotary diamond dressing.

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MIAMISBURG, OH - United Grinding Technologies, Inc. (UGT) announces the Zeus M, the latest high-performance CNC universal grinding machine for round and non-round shaft parts from Studer Schaudt.

The Zeus M is designed for volume production of camshafts, crankshafts and gear shafts, as well as steering assembly parts, eccentric shafts, axle components, turbo rotors and others. With a grinding length up to 950 mm, a maximum diameter 430 mm, and a center height of 220 mm, the Zeus M handles workpieces weighing up to 80 kg. The Zeus M combines cylindrical, non-round, plunge and high-speed peel grinding (HSP) all in one machine.

A polymer Granitan machine bed provides optimum vibration dampening and thermal stability. The sliding Z-axis with digitally controlled ball screw drive and X-plus Z-axis with hydrostatic guideways offer ultra-precise axes positioning and repeatability for precision shaft grinding. High-frequency motor spindles combined with galvanic-bond and ceramic-bond CBN grinding wheels from 70 mm to 650 mm diameter enable constant circumferential grinding wheel speed of up to 200 m/sec.

The results are short grinding times, long-lasting tool life and optimum grinding performance. The 130 mm rotary diamond dressing form roll is positioned next to the tailstock for easy access, while assuring precise dimensional accuracy between the dressing tool and the grinding wheel.

CBN and compressor shafts

In most cases, gray cast iron compressor crankshafts are ground with corundum tools under optimized processing conditions, a situation that provides very little room for process improvement. However, the use of CBN as a grinding medium opens up new possibilities.

Earlier attempts to introduce CBN failed for a number of reasons - excessive cost, high wear and tear resulting from slow cutting speeds, unsuitable dressing tools and a low degree of machine rigidity.

The Zeus M has been designed and optimized specifically for the use of CBN. Cutting speeds of 200 m/sec, rotating diamond dressing tools and superior machine stability make the Zeus M an ideal CBN machine. And compared to conventional grinding approaches, CBN considerably increases the intervals between dressing and grinding wheel changes.

Clamping chuck

Another problem confronting users of more conventional process solutions is clamping the crankshaft in the eccentric chuck in order to machine the lift pin. The crankshaft is clamped eccentrically into the chuck so that the crank pin can be centered and ground cylindrically. As a certain amount of adjustment is necessary for eccentricity, expensive clamping devices and large chucks are often required.

Special chucking is no longer necessary with the Zeus M. The workpiece is clamped with ease in a central clamping chuck, and the pin is cylindrically ground using a programmed path operation. The eccentricity changeover takes place in the machine control, and manual adjustments are no longer necessary. All of this adds up to higher precision, more flexibility and shorter changeover times.

Features

The Zeus M workhead has a C-axis speed range of 1 to 300 RPM. Spindle torque is 25 Nm. The work center is typically MT 4. Tailstock quill stroke is 150 mm.

Depending on the application task the optimum guideway system can be selected accordingly. This could be the cost-effective linear anti-friction guide-way system for cylindrical grinding, the ball bearing system or the hydrostatic guide-way with hydrostatically threaded spindle for camshaft grinding.

For the two-slide versions the concept of the guide-way systems allows the movement of the two slides right next to each other with only a very small safety gap for the grinding wheel protection covers. As a result, even cams or journals positioned closely to each other can be ground simultaneously.

State-of-the-art Siemens digital control and SIMODRIVE axis drive components are at the heart of the new Zeus M. Machine operation, setup, changeover, dressing and programming of even complex parts are easily accomplished through an innovative step-by-step, on-screen operator interface developed by Studer Schaudt. The Siemens Sinumerik 840D control package features application-specific software routines. WOP (work oriented programming) system permits automatic generation of speed profiles from just a few parameters. Remote diagnostics, process control and trouble-shooting via standard telephone line and machine modem link are easily facilitated.

CNC Machine suits rotary deburr or grinding applications

Developed for plier grinding applications, CNC Rotary Deburr/Grinding Machine consolidates 3 stations on single dial. Hand operations or single station rotary belt grinding operations can also be performed. Standard features include belt speed of 4,000-7,500 fpm, self-contained coolant system with filtration and magnetic separator, speed modification capabilities at each station, real-time head position and pressure monitoring, and Ethernet capability.

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Ultra Tech Machinery's has developed a CNC Rotary Deburr/ Grinding Machine. The technology incorporated into this machine positions it as one of the highest production machines of its type on the market. The machine was developed specifically for a plier grinding application, but the design can be utilized in any CNC rotary deburr or grinding application.

The equipment consolidates three stations on a single dial, tripling plier production. In addition, hand operations or single station rotary belt grinding operations are all performed by this diverse machine. Completing all operations in one fixturing resulted in improvements in consistency, quality and productivity.

CNC retrofit improves accuracy and productivity for aerospace components

Stellex Monitor Aerospace Inc. (Amityville, New York) has completed a total CNC retrofit on the fifth of its ten Cincinnati Milacron gantry-style milling machines, which are used in the production of titanium and aluminum aerospace components. The turnkey retrofits were provided by the Siemens Machine Tool Business (Elk Grove Village, Illinois).

Originally equipped with Acramatic "Big Blue" controls, these machines now have Siemens digital servomotors and drives, Sinumerik 840D CNCs running on a Windows XP platform with 3D five-axis cutter compensation and full five-axis real-time kinematical transformation. According to Stellex Vice President Gary Kahrau, the results have already been documented to include reduced setup time, improved surface finish, reduced secondary finishing operations and significant improvements in overall productivity.

The company operates a 250,000 square-foot modern facility. There, it produces struts, spars, landing gear, bulkheads, crown beam assemblies and other medium to large parts from titanium, aluminum and stainless steels for commercial and military aircraft and aerospace vehicles, including space shuttles.

Mr. Kahrau elaborates on some of the 840D features that are benefiting the company. "The open architecture of the control allows us to create our own screens and integrate with our ERP system," he says. "We store all of our own data on a proprietary ERP system. The data files are dispatched to the CNC, where our custom Shop Workstation program resides. It handles the handshake of the data files with the control. This program is fully integrated with the control's tool management system as well."

With the real-time five-axis kinematical transformation called Traori, the 840D control can directly accept the part's workpiece definition data.

"With the extreme metal removal rates, deep pockets and long contours typically encountered in aerospace production, this feature of the CNC has demonstrable upsides every day for Stellex," says Mr. Kahrau.

He further expands upon the open HMI of the CNCs being retrofitted on the Stellex machines. "A cutter diameter compensation and customizable tool management system onboard the 840D give operators quick and accurate information in real time, plus it has the capability to accept additional features as the application demands," he explains.

Siemens also provided Stellex with an advanced dynamic machine engineering analysis called Mechatronics. First, it collects critical real-time machine performance data, and then it establishes optimized parameterization of the CNC and servodrives. Finally, the analysis verifies optimized performance of the machine. Mr. Kahrau cites the servo analysis, ball bar tests, acceleration/ deceleration tests, bi-direction compensation work-up and other protocols as being key to the end results. "Our machinery accuracy is better now than when the machines were new, our five-axis gantry has never performed so well and the rotary axis error was literally cut in half."

CNC grinder helps start a business

With the economy beginning to head south, many manufacturers were searching for ways to cut costs during the late 1990s. To many, this would seem to be an inopportune time to start a niche grinding business. However, viewing the proverbial glass as being half full, Joe Scolaro saw this period as a window of opportunity.

At the time, Mr. Scolaro was a manufacturing department supervisor at a Cleveland plant, and he felt he'd "hit the ceiling" as far as potential for career advancement. He met a machinery dealer who had a used manual Studer from United Grinding (Miamisburg, Ohio) on his floor. Mr. Scolaro bought it, leased a 2,500 square-foot space, and, along with partner Dale Stebner, began knocking on doors. Thus began Venture Grinding, Inc. (Cleveland, Ohio).

Since that first used manual Studer 6 years ago, Mr. Scolaro and Mr. Stebner have bought three others--an S21, an S36 and the latest model, the S31 with a full B axis, which permits combining several operations in one chucking.

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Mr. Scolaro says he started Venture Grinding to fill a niche. "Most machine shops don't have a grinding department," he says. "They do extensive turning and milling, but when it comes to grinding, most send the job out, primarily because grinding is a specific and highly variable discipline. Hardness, grit size, makeup, the dressing method and coolant are among the many aspects to be considered.

"You can teach programming relatively easily, but in a grinding operation, you must take your eyes and ears out on the floor," he continues. "Listening and feeling for vibration can indicate how a part is running. For instance, the operator can ascertain if the wheel is too hard, if the part is getting too warm or if the coolant concentration needs to be modified.

"I don't want to call grinding an art form, but there's certainly more involved in finishing a ground part than in turning or milling a part," Mr. Scolaro adds.

According to Mr. Scolaro, the last 4 years have been rough. A lot of shops Venture Grinding's size and larger have not survived. The companies that have remained, the OEMs and the bigger machine shops, have had to make every possible effort to reduce costs.

"I knew someone was still going to be making small lots of complex parts, and we stepped up our sales efforts and won jobs," Mr. Scolaro says. "Being a startup, leasing shop space, having the best machines and having low overhead, we were able to give customers a more competitive price. Sometimes we were offering same-day turnaround to get the business. That's something that companies who went overseas with their parts gave up--quick response."

One of the many factors Venture Grinding attributes to its success is the communication between the company and its customers. Mr. Scolaro explains that, in most cases, grinding is the last in a series of several operations. For instance, many jobs the company receives are from heat-treating operations. If the upstream processes fall behind in schedule, it's difficult for the company to make up the difference.

"We try to maintain a schedule, while still being flexible," Mr. Scolaro says. "If we get an order with a few days notice, it's not a problem. Because of the flexibility and reliability of the Studer machines, we can run jobs as small as two pieces to lots comprised of as many as 10,000 pieces." The Studer pictogramming and the quick-set programming feature makes rotating the B axis; maintaining the relationship between the wheels and the part; and change-over, setup and training relatively easy.

Another strategic tip Mr. Scolaro offers is the 20 percent rule. He says he tries to never have more than 20 percent of his work tied to one customer; in fact, 20 percent makes him nervous. It's not that the company turns away large orders, but it continues to look for new customers so that it is never in a position where there will be serious problems if a customer sends work overseas.

Currently, Mr. Scolaro says the company has about 16 or 17 percent of its work tied to one customer. However, he notes that taking this percentage rule too far in the other direction--for example, having less than 4 percent or 5 percent tied to each--would be unfeasible. "It would be impossible to keep track of who was doing what for whom and when, which would make scheduling problematic," explains Mr. Scolaro.

Verify CNC program correctness

All CNC programs must be verified. While new programs present more challenges than proven programs, operators must be careful and alert during every step of a program's verification.

Step 1: Verify the correctness of the CNC program. This step is required for new programs or for programs that have been modified since the last time they were run (possibly because of engineering changes). It is also necessary to do this step if there is any doubt as to whether you are working with the current version of the program (after making changes at the machine the last time the job was run, perhaps the setup person forgot to save the program).

The objective of Step 1 is solely to confirm the correctness of motions commanded in the program. Other potential problems will require further verification at the machine; however, when Step 1 is successfully completed, the setup person will have confidence in the motions made by the program.

Some operators perform this step on the CNC machine during setup, which requires time. Many current model CNC machine tools have built-in toolpath displays, and as long as you verify the new program while the machine is running, you won't interfere with production. Not all CNC machines allow you to view one program's toolpath while another program is running. In this case, Step 1 will add to the setup time. If mistakes are found, the time it takes to correct them will also add to setup time.

Not all CNC machines provide toolpath display, and it is difficult to see a program's true motions by watching a CNC machine run a program. You may not be able to achieve the objective of Step 1 in this case because there might be serious mistakes to be found and corrected in Steps 2 and 3.

With the affordable off-line G-code level toolpath verification systems available, Step 1 can be performed for upcoming jobs, while the machine is running production shortly after a CNC program is created or modified. With these desktop computer-based systems, users can gain a better view of the program's movements than they could by watching the machine move.

If using an off-line system, the programmer is usually responsible for this step. They will perform this step shortly after the program is created. While most CAM systems have toolpath verification that is done as the CNC program is created, if changes are made to the G-code level program, many CAM systems cannot display the changes.

Even if changes are not made to the G-code level program, I recommend using a G-code level off-line program verification system to check the program's motions. If nothing else, this gives the programmer another way to see the motions a program is going to make before it is run on the CNC machine.

It takes a watchful eye to catch mistakes with an off-line system. Because the job is not currently on the machine, there is no real urgency, so mistakes can slip by. It might help to have someone else perform this step (another programmer or a setup person). Because the original programmer is so familiar with the job, he or she might not catch obvious mistakes. A setup person can be the best bet, since he or she will be responsible for actually running the program at the machine.

Many off-line systems don't show the location of clamps and other obstructions, so the person verifying the program must be able to visualize the placement of workholding components around the workpiece. The more problems they catch, the fewer problems there will be for the setup person to find and correct.

There may still be problems with the program's motions alter Step 1 is completed, but these problems should not be severe. Even with a toolpath display, it can be difficult to catch small motion mistakes. Some solid model-type program verification systems allow performing measurements on the virtual workpiece machined in the system; however, you must suspect that a problem exists before taking a measurement. For instance, with a mistake of less than 0.01 inch, it is likely that you may not suspect that anything is wrong.

Software aids in wheel design for CNC tools and grinders

Suited for X Class range of CNC tools and cutter grinders, Wheel Editor v27 includes key hole punch software for creation of punch geometries from library of shapes. Software also enables creation of customized contours and punches with concave and convex shapes. Additional features include Delta-C R850 drill point sharpening function and Profile Pivot Editor function to optimize feedrate.

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Melbourne - ANCA has recently released version 27 for their X Class range of CNC Tools and Cutter Grinders. This version is packed with new innovative features that make the performance of an ANCA machine more efficient, provide significantly extended flexibility and enhance the possible spectrum of applications. The two main new features with version 27 are the addition of Key Hole Punch software and Delta-C R850 Drill Point. This increases the applications on version 27 to more industries. The Keyhole Punch software allows creation of punch geometries from a library of shapes and also allows creation of customised contours. Unlike standard punch grinders this solution is able to create punches with concave and convex shapes. Once the shape is designed the software will specify the wheel shape required to grind the punch. This wheel shape can then be loaded into the ANCA Wheel Editor. The Delta-C R850 drill point has been implemented in iGrind and is available in the drill wizard. This is a proprietary drill shape. Version 27 enables sharpening of this drill shape under license.

Version 27 has a wide range of applications, which enable users from many different industries to utilise its broad and flexible functionalities. Some of the more common applications which have been improved are:

Profile

Profile Pivot Editor function is a new feature of profile software. This option changes the way in which nine o'clock grinding positions the wheel. If full control is selected then the pivot angle can be specified at the start and end of each profile element. An option has been added in profile grinding that allows the feedrate to be optimised to maintain a constat passage of the grinding point across the profile.

Step

The wizard has been added to the Step editor operation that will allow a single DXF file to be split into multiple step sections. A new menu has been added to the Step Editor operation that allows geometry to be displayed and selected in iView.

Mist Collectors For Enclosed CNC Machines - Brief Article - Product Announcement

The model F-275 Filtermist mist collector, designed for use primarily on enclosed CNC machines with an internal volume between 28 cu. ft. and 80 cu. ft., will be exhibited.

The 6" diameter intake results in very low intake velocity, reducing the likelihood that chips and large droplets will be drawn into the unit, the company says. Though designed to be mounted directly on the top of a machine, this model can be modified to be mounted on a stand or to be suspended above a machine.

The units are designed specifically for oil mist and smoke produced by machine tools such as lathes, mills and grinders. These mist collectors are intended to protect personnel from these pollutants.

A CNC Solution For Cells, Lines And Machines - C64 CNC, advanced hardware technology - Brief Article

The company has developed the C64 CNC, which is designed for control of manufacturing cells, transfer machining lines and rotary index machines. Along with the ease of integration to line applications, the C64 incorporates all the features and specifications expected from a high-end CNC. Incorporating a high level of PLC technology, the C64 CNC allows for reduction in man-hours for design work with built-in PLC functions. Also, the line dedicated graphic user interface function shortens the debugging time. Moreover, the improved diagnosis function is said to minimize equipment downtime.

The advanced hardware technology has up to 14 axes of control, and using the multiple system function, one C64 CNC is capable of controlling up to seven program paths simultaneously, thus reducing overall machining line cost. Multiple C64 CNCs can be connected to the same control network to control unlimited module machines in a control line. Operating ease and work efficiency are both enhanced through the use of the "selective machining" and "process machining" functions, making it possible to graphically select only the processes and machining steps that are to be executed, according to the company. The open connectivity to major networks such as the MELSEGNET/10 and CCLINK, as well as Ethernet, Profibus, and Devicenet allows the C64 to interface with other peripheral devices, including remote IO as well as existing shopfloor management schemes.

Extended instructions broaden the control range to provide control. PLC instructions have been increased. "Multiprogramming" allows design sharing and process-by-process design. A multiple number of PLC programs can be entered and executed, enabling program design sharing and structural division by function, process or designer. With the GPPW programming tool, editing of PLC programs within the C64 can be done concurrently without stopping the built-in PLC. PLC loop control can be performed for each axis of multiple systems, using a one-axis program to save program development time and minimize the number of steps.A high-resolution 12.1" LCD, Windows CE touchscreen terminal increases functionality and flexibility. By using this terminal, the machine builder can use the standard interface or create a customized interface utilizing Visual basic or Visual C++. The terminal carries an IP65 rating and is 55mm deep, allowing for installation in severe environments and in shallow enclosures.

METALCUTTING: Turning Machines and Centers

Turned parts cover such a broad range, from slender shafts and tiny precision connectors to large-bore oil-patch tubing and huge turbine shafts, that it's hard to imagine how they fall under the same category of single-point metal removal.

Whether used in the toolroom or for rapid prototyping or for high-production applications, turning centers depend on the latest advances in machine design, control technology, software, and automating load and unload devices for their effectiveness.

Visitors to IMTS 2006 can expect to see technology solutions that reflect the demands of manufacturers for singlesetup production of more and more complex parts to ever higher levels of quality. Here's what visitors should look for:

* CNC lathes with live tools, C axes, subspindles and Y axis have the capability to drill and mill off center, and are much in demand for complete part processing in a single setup.

* CNC lathes approach full multitasking capability with a B axis that allows rotation around the Y axis for drilling at an angle or contour milling off the spindle centerline
Classes of machines such as vertical turning centers and Swiss turns continue to enjoy demand because of growth in markets, including energy, aerospace, medical, and machinery.

For high-production applications, turning machines have evolved with multiple spindles, adding to the number of single-point tools that can be applied to the same part or machine multiple parts in a machine cycle.

Machines that add live (driven) tooling in the form of milling cutters, drills, and sundry other tools can perform turning and milling and other processes in a single setup, and approach true multitasking machines in capacity. Multitasking machines will be covered in the next section of our show preview.

Going to IMTS in search of your next turning machine involves adopting a strategy based on the volume and complexity of parts to be machined, the need for quick-change

change workholding and tooling, desired quality of finished part, and ease of programming. It could he a simple two-axis lathe or a Swiss-turn capable of producing the most complex precision parts in as many as ten axes.

For medical applications, electronics connectors, and a host of similar precision-machined parts, Swiss turns that machine bar, typically to 32-mm diam, are following a number of courses in development.

"Manufacturers are requiring faster changeover, as businesses want smaller hatches and smaller quantities," explains Tom Dierks, president, Tornos Technologies US Corp. (Brookfield, CT). "There is a need to set up faster and change over faster, relying on quick-change tooling or quick-change barfeeders with different bar sizes," Dierks says.

"Tornos has done a lot of things to its Swiss turns to overcome the limitations of the number of tools, for example taking a tool position and tooling it up to handle two or three tools to open up more tool positions on the machine. That's essential for more complex parts typically found in medical applications and some automotive and electronics Darts." Dierks says.

For moderately complex parts, Tornos will exhibit its Deco 20s six-axis machine. It has been boosted to a 20 (25.4)-mm diam size and features a mirror image front to back sliding headstock on the front and sliding subspindle on the back, and gang slide on front and back. "It's a much less expensive option for the user who only requires five or six axes, and it can be configured a la carte or packaged with barfeeder and driven tools for under $200,000," says Dierks.

"IMTS attendees will quickly notice that today's machines are moving in two distinct directions," says Brad Morris, president of REM Sales Inc. (East Granby, CT). "Manufacturers are being driven to do more with less, looking at all of their processes for ways to reduce or eliminate operations while improving flexibility. In doing so, many are purchasing multifunction lathes, including Swiss turns, as solutions.

"In response to this market need, Swiss turn builders are producing more complex machines capable of simultaneous operation. Many of these new machines include turrets and driven tooling for milling, drilling, and other operations not typically performed on lathes," Morris explains.

"Attendees will see more machines than at any previous show capable of helping them consolidate operations in one machine and drop parts complete. At the same time, Swiss-turn builders are also developing simpler machines that are cost-effective solutions with decent capabilities for manufacturers producing parts that demand flexibility, but don't require complex machining operations," Morris explains.

"To an outsider, it might appear that these two strategies run counter to each other. In actuality, they are working together to help machine tool builders broaden their product offerings and provide more comprehensive solutions to their customers," Morris says.

CNC Software is built on open control architecture

OpenCNC[R] v6.5 enables manufacturers to integrate off-the-shelf hardware and software technologies. Set of lathe macros helps saves programming time, while hand-wheel feed feature lets user hand feed job stream up to programmed cutting and traverse speeds. Software also provides compiled HTML help menus, lead screw compensation for rotary axes, and Sercos SoftSERCANS support. With winPlot, users are provided with clear, 2D plot of machine moves.

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Manufacturing Data Systems, Ann Arbor, MI, announces the release of OpenCNC[R] Version 6.5 with a host of features that saves programming time and improves usability across a wide range of machine tools.

OpenCNC software, the first production-proven, unbundled, software CNC built on an open control architecture, enables manufacturers to save cost and keep up with rapidly advancing technology by integrating off-the-shelf hardware and software technologies. It was introduced to the market in 1990 and is installed on thousands of machines across a range of industries.
New set of lathe macros, including profile definition, finishing, grooving, roughing, and tool definition saves programming time, delivering the maximum machine motion for minimum programming time.

o The new Hand-Wheel Feed feature allows the user to hand feed a job stream up to the programmed cutting and traverse speeds. Handy for debugging programs, this feature allows the user to control machine motion and watch the machine tool follow a programmed path and avoid potential collisions or misfeeds in the program.

o Help menus are now compiled HTML allowing for easier searching and navigation.

o Improved lead screw compensation for rotary axes reduces complexity in set up, saving programming time and contributing to machining accuracy due to improved positioning.

o A low-cost assist for analog servos, a new driver for Sensoray526 card also will be included in the new OpenCNC release. The Sensoray526 card is an economical reader of an encoder input used to run a servo.

o Broadened Sercos SoftSERCANS support with the addition of drivers that will run more variations of Sercos drivers in use on machines today, making OpenCNC even more widely applicable to more different machine tools.

SERCOS (SErial Real-time COmmunications System) is an open, fiber-optics-based, CNC-to-digital drive interface standard. Interfacing a completely open, all-software CNC with an open digital communications standard allows the power and tuning of a servo drive to be managed entirely in software from a single PC, with just one fiber optic cable and a passive communication card between the PC and the drive.

The benefit of the OpenCNC SERCOS interface for machine tool builders and end-user manufacturers is enhanced servo performance, improved part finish, and the cost savings associated with using standard digital interfaces and non-hardware-based open solutions for communications to the machine tool versus using proprietary digital or analog drives.

Other new features include:

o The new winPlot feature allows users to display the machine coordinates during operation for diagnostic and prove-out purposes. The feature provides a clear, two-dimensional plot of machine moves.

o The winSevView feature makes it easy to search and view specific patented Significant Events / files. Significant Events are time-stamped events stored in the control in order of occurrence. With this new tool users can quickly review significant events from any time in the machine's operating history.

Unlike proprietary CNC controls, OpenCNC requires no proprietary hardware or motion control cards. Combining a soft CNC and soft PLC in a single application, OpenCNC is well suited for new equipment as well as machine control replacements and allows the easy and regular installation of software updates. OpenCNC also provides essential software tools and diagnostic features for customizing servo, spindle, ATC and other hardware interface options.

"In an industry dominated by proprietary hardware CNC solutions, MDSI has proven that high-end, multi-axis CNC machine tools can be controlled entirely from software-without any motion control cards, proprietary hardware, or embedded firmware," said an MDSI spokesperson.

OpenCNC provides a common control technology across a full range of machine tools: single- and dual-turret lathes, single- and multi-spindle precision drills, routers, mills, grinders, gear hobs, dial index machines, and gantry machines-all from a single operating system, running from a single processor.

Waterjet Machines work with EDM technology

Available in 3 models, Waterjet series include stainless steel tanks, dedicated nano control, and 15 in. waterproof screen. Featuring 2D CAD-CAM software, 2-3 axis Classica offers accuracy of [+ or -]0.004 in. Suprema 4-axis' software includes Intelligent Tapering Control that corrects tapering of cut and achieves [+ or -]0.001 in. wall straightness in 1/2 in. thick steel. Evolution 5-axis' 3D System uses rotation point device to maintain constant distance from nozzle to workpiece.

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Wood Dale, IL - Mitsubishi introduces the first waterjet line designed specifically to work hand-in-hand with EDM technology. The Waterjet line brings speed and flexibility to EDM shops, while maintaining the level of reliability and accuracy required in EDM manufacturing.

Mitsubishi experts have played an active role in the Waterjet machines' design, making sure they're engineered specifically to work with EDM technology. Mitsubishi engineers are constantly delivering ways to increase efficiencies and boost productivity. The machine's speed is ideal for reducing production times attached to roughing and bulk material removal before finishing on EDM. For example, a time study showed a 28% time savings on materials roughed with Waterjet versus an EDM machine.

The Waterjet series is available in three different models to best fit every shop's needs. These include the 2-3 axis Classica, 4-axis Suprema, and 5-axis Evolution.

The machines feature stainless steel tanks for easier maintenance and cleaner cutting conditions. A solid base construction and custom-made table for accepting tooling systems allows Waterjet and EDM to easily work together.

The Waterjet line is powered by Mitsubishi Electric, giving it more programming capabilities than other waterjet manufacturers. The Mitsubishi 700 Series Control provides unprecedented productivity and operating comfort. Dedicated Nano control helps achieve high-precision machining. The unit is controlled on a 15-inch water-proof screen, with improved graphics and NC design to simplify operation.

The 2-3 axis Classica features 2D CAD-CAM software with nesting capabilities, and accuracy and repeatability of [+ or -] 0.004".

The 4-axis Suprema's software features (ITC) Intelligent Tapering Control, which correct tapering of the cut automatically. The CNC tilts the high-pressure water jet [+ or -]2 degrees which allows for increased cutting speeds in a contour. The ITC system can achieve [+ or -]0.001" wall straightness in half inch thick steel.

The Exclusive 5-axis Evolution 3D System uses a self-positioning rotation point device on the material to automatically maintain a constant distance from the nozzle to the workpiece. This protects the nozzle through a working range from flat work to a contoured interpolation of [+ or -]69[degrees].

The Mitsubishi Experience is providing customers with the ingenuity and innovation to stay competitive on all levels. We deliver industry-leading technology and integrated solutions to help you reach new manufacturing heights. The Mitsubishi Experience is the unparalleled support of our sales and service teams, the knowledge of our application engineers, and the expertise from specialists dedicated to maximizing your productivity.

Tecumseh sets its course: a very different kind of CNC software paves the way for creating an integrated manufacturing environment

A journey of a thousand miles starts with a single step."

This ancient Chinese proverb is good to keep in mind when thinking about how a factory begins to move toward a plant-wide electronic production monitoring system. The vision of the future destination may be luminous and compelling, but turning this vision into reality is no hop, skip and a jump. It has to be taken earnestly and carefully, step by step.

In the end, plant managers will be able to access the system and get instant, up-to-the-moment reports summarizing the OEE (Overall Equipment Effectiveness) rating of the whole plant, separate production lines or even individual machine tools. Analysis of the collected data used to calculate this rating will pinpoint where problems or opportunities for improvement appear.

Here is an example of what is to come when a production monitoring system is in place: Managers are alerted to a report showing that a certain machine in one of the machining lines needed an average of 3 minutes cycle time during the last shift when it should have been closer to 2 minutes at programmed feed rates and spindle speeds. Reviewing the log of events that occurred during this shift shows that a grinding wheel was not cutting as aggressively as intended and had to be replaced at 50 percent of its expected life as a result of excessive wear. A recent change in wheel grade is recorded in notes entered by the manufacturing engineer. At the start of the next shift, a message to the cell operator gives instructions to install a harder grade wheel. Cycle times monitored during the day show a return to the required output. Problem solved.

This vision is not new. It's been talked about and dreamed about for years. In fact, the software and hardware to make it happen not only exist, but they also have a proven track record. What is becoming clear is that making the transition to this future state will be neither quick nor effortless. The first steps are the toughest, but that is where the journey begins, as the proverb reminds us.

Tecumseh Products' compressor plant near Tupelo, Mississippi, has taken those first steps, and the benefits are already clear and substantial. The plant has installed software-only CNCs on several "bottleneck" machine tools and is running key portions of a bidirectional production monitoring system that integrates the CNCs with the plant's existing computer network and ERP software. Plant management is taking the results of these initial installations as proof that these steps are definitely moving in the right direction.

Under Pressure

Although Tecumseh Products is best known for its small engines found on leading brands of lawn mowers, snow blowers and similar products, the company is a major producer of compressor motors for refrigerators and air conditioners. Consumers are not likely to be aware that the reason these products run so quietly and efficiently is the unseen presence of a Tecumseh-built compressor inside, yet the reliable performance they enjoy is dependent on the quality of those compressors. Because many of the major brands of refrigerators and air conditioners have moved production offshore, Tecumseh has had to redouble its efforts to maintain profitable operation of its compressor plants in the face of the cost pressures brought on by the severe contraction in U.S.-based appliance manufacturing.

In Tupelo, Tecumseh operates three main machining lines that feed an assembly line on which the various compressor models are built in a mix that is determined by a schedule of firm customer orders. This plant houses about 100 active metalcutting machine tools. A shop control system that relies on manual data entry allows managers to monitor production, but the information is at least 1 day old by the time it is available for analysis and response. The system tells managers basic information about labor input, machine output and scrap rates. This gives them a somewhat sketchy picture of where the bottlenecks are and when part shortages may affect the assembly line. It is adequate to tell them how to react but rarely helps them anticipate and avoid shortages that hamper the assembly line. It can't tell them what is happening inside each machine to reveal the causes of bottlenecks.

Four-Spindle CNC Lathes

To maximize productivity, SB Machine Tools (Schaumburg, IL) offers Kitako four-spindle CNC lathes. With the four-spindle concept, zero loading/unloading time and virtually uninterrupted productivity come true. With their independent spindles housed in an indexing carrier and working in pairs, two preloaded chucks are continually cycled through the machining compartment. Upon completing each cycle, the carrier indexes at 180°-the two loaded spindles go to the machining area and the two "job-done" spindles go to the loading and unloading area.

Two independent turrets work on the two different, or identical, parts simultaneously, providing broad flexibility. Employing either manual loading or an automatic servo-driven loading system, the part loading process is accomplished during the machining cycle. It is very possible for just one operator to run two machines, which is equivalent to the productivity of almost five to six single-spindle CNC lathes. Kitako technology is available in both horizontal and vertical models covering 4-22" chuck sizes. Each is capable of being customized to maximize its productivity and profitability.

Contact SB Machine Tools, 1300 Remington Rd., Unit K, Schaumburg, Il 60173; Ph: 847-882-9600; Fax: 847-882-9800; or Circle 454.

Reaching New Depths And Greater Accuracy

Just when you thought high speed machining or hard milling would steal the best applications from ram-type elertrical discharge machines, linear motor technology is taking "sinker EDM" to levels unattainable with any other metal removal process.

Mike Province, the vice president of Clarich Mold (Westchester, Illinois) had planned to take a vacation over the Christmas holiday but that was not going to happen. He needed to burn one more mold on his CNC ram-type (sinker) EDM. The electrode, about 4 inches wide by 6 inches long, had complex geometry and deep ribs. Instead of using those four vacation days, Mike got stuck at the shop "babysitting" the EDM process--constantly adjusting the cutting conditions and the flushing ports. Almost a year later that same job came through the door again, only this time, Mr. Province burned the job on his new EDM with linear motors. Instead of spending four days burning the mold, he spent only 15 hours. The new machine completed the job faster because it did not require any special flushing setups.

Adapting linear motors on machine tools has created a lot of interest in the last few years. This interest was apparent at Chicago's International Manufacturing Technology Show in September 2000. Several major machine builders including Cincinnati Machine, Mazak and Sodick unveiled various types of machines with linear motor drive units. Other manufacturers of servomotors or control units such as Fanuc, Mitsubishi Electric, Yaskawa and Siemens also displayed linear motor technology.

Linear motors are not a new invention. Rather, they are an innovative adaptation of an existing technology. It is, in fact, the very same technology that propels roller coasters and bullet trains to record speeds in Japan. What makes the current linear motor units so intriguing is their entry into mainstream machining operations. Many industry observers believe that linear motors will have a dramatic impact on the design of machine tool axis motion, outmoding the present technology much like CNC did to control systems a few years ago.

Linear motors are rather simple. On a CNC ram EDM, two series of magnetic plates are mounted on the Z-axis quill, along with fixed magnetic coils on each side of the axis. The basic components of a linear motor are shown in Figure l. A linear scale with very fine resolution is mounted to the Z-axis quill in order to detect axis movement location. As the control signals the Z axis destination, electrical current is introduced into the copper coils, which are adjacent to the magnet plates. The resulting difference in polarity between the plates propels them in opposite directions. Because the one set of plates is fixed, the other set is driven rapidly along its path. The more current that is introduced, the faster the moving axis will travel. The Z axis can travel more than 1,400 ipm, or nearly 22 times faster than a traditional ballscrew equipped EDM.

No Backlash

With conventional motors, before any movement is realized, the electrical motion (rotation) must be converted into mechanical (linear) motion through the use of belts, gearboxes or ballscrews. All of these conversions introduce issues of mass, inertia, backlash, lag-time, overshoot, friction and heat. Even in the case of direct-drive systems (where the motor-shaft is mounted directly to the ballscrew), it must first overcome the mass, inertia and friction of the ballscrew mechanism before it encounters the mass, inertia and friction of the table and the workpiece weight. Then of course, to stop this motion, the same amount of time and energy is required. With linear motors, most of these issues are reduced or eliminated because no conversion from rotational to linear motion takes place.

Although a linear drive produces less torque at low speed than conventional drive systems do, EDM machines don't have high-torque, high-load requirements as chip cutting machines do. Therefore, this characteristic is not an issue for EDM. Because EDM is a non-contact machining process, it is a perfect fit for linear motor technology. Unlike machining centers that take advantage of the table speeds of linear motors, EDM uses linear technology's speed for the Z axis (ram stroke) in order to create its own flushing capability. EDM also uses the speed of linear motors to react to changes in the spark gap. Linear motor EDMs will excel in difficult-to-flush applications.

Retrofit Increases Productivity And Reduces Capital Outlay

Monitor Aerospace Corporation of Amityville, New York, is a producer of aerospace structural components for companies such as The Boeing Company. The company invested heavily in the 1970s in large expensive machinery, but more than 20 years later these aging machines were no longer keeping up with productivity demands. The older controls on these machines had limited functionality, and operators had to continuously tweak the machines to compensate for wear. Moreover, maintenance costs were soaring and downtime was increasing.

Gary Kahrau, director of manufacturing engineering, and Chris Nagowski, facilities manager, had a dilemma. They needed to address the machines' performance problems, but they did not have access to the enormous capital outlay necessary to replace them. Mechanically the machines were in fairly good condition, so they decided to explore retrofitting the machines with new controls as a solution to their problem. They knew that new controls would provide more flexible functionality, higher reliability and less downtime, but they also hoped that newer error compensation capabilities would help make up for some of the machines' wear related tolerance problems.

As Mr. Kahrau and Mr. Nagowski explored their retrofit options, their first task was to decide on a control. They wanted a control that would give them ease-of-use, high reliability, and sophisticated capabilities such as five-axis movements and advanced error compensation. Just as importantly, however, they wanted an open control that they could integrate into their existing plant system architecture and that would be poised for integration with undefined systems of the future.

Traditional controls offered the motion and compensation sophistication they were looking for but did not offer the flexibility and integration capabilities they wanted. On the other hand, purely PC-based controls, which offered the integration and operator flexibility they wanted, did not offer the motion sophistication they needed.

As their search went on, Mr. Kahrau and Mr. Nagowski spoke with CNC Engineering, Inc. (Enfield, Connecticut) and learned about CNC Engineering's PC-based Open Vision HMI system for the GE Fanuc series of controls. This system provides a hybrid solution that ties together a flexible and powerful PC-based front-end with the motion and compensation capabilities of a GE Fanuc control. Based on GE Fanuc's HSSB, and using an industrial PC for the operator interface, Open Vision HMI provides access to all of the control's native functions through intuitive touch screen menus. And, since the operator interface is on a PC running Windows NT, custom screens and options are readily available, and advanced network and system connectivity is fully supported.

The first machine Monitor decided to retrofit was a three-axis Cincinnati Bridgemill. This was a sound machine, but the X-axis gearboxes were worn, and the machine was not holding tolerances well. Rebuilding the gearboxes would be an expensive undertaking, and Mr. Kahrau and Mr. Nagowski thought that this expense could be avoided by applying some of the advanced error compensation functions available in a newer control. Working with CNC Engineering, a specification was developed for the control. For this application, Monitor decided to use a GE Fanuc 15MB control with CNC Engineering's standard Open Vision HMI Software. (The front-end software would run under Windows NT Workstation, and the PC initially would be connected to Monitor's Local Area Network via a standard Ethernet topography.) Since the GE Fanuc control had many options that might help compensate for the worn gear boxes, it was decided to add compensation features one at a time and perform accuracy tests after each feature was implemented to quantify the results.

Monitor has tight production schedules, and it could not spare the machine for the protracted period of time associated with a full in-field retrofit. CNC Engineering's CPR (Certified Pre-assembled Retrofit) package solved this problem. Under the CPR program, engineering and design specifications were worked out in advance during an initial site visit. During the site visit, detailed measurements were taken of the machine, and new component placement was finalized. The engineers at CNC Engineering spent considerable time working with Monitor to specify the optimum operators' pendant for the application. In this case, the original operator console was removed, freeing up a large amount of floor space, and a new three joint operator pendant was designed for maximum operator convenience. With the information from the site visit the entire retrofit package was engineered, designed and assembled at CNC Engineering's facility. During the engineering and assembly phase all necessary electrical schematics, cable lis ts, panel layouts, mechanical prints and ladder programs were developed. The exact equipment that was to be installed at Monitor was then assembled, wired and powered up. All parameters were loaded into the control, and the entire package was then tested exactly as it would be on the machine--right down to servomotors with their custom length servo cables. Once testing was finalized, the package was shipped to Monitor for field installation. For this machine the installation took 3 weeks.

Techno trucks: Roush racing

I'n a western suburb of Detroit, the Roush Racing NASCAR Craftsman Truck teams have been busy all winter preparing for the 1999 season opener in Homestead, Florida. The snow-shrouded shop could be mistaken for any other factory in a row of commercial buildings that line the service drive of a major expressway leading into downtown Detroit. But inside lies one of the most organized and complete shops in racing.

Don't tell Jack Roush that NASCAR teams must be located in the Carolinas to be competitive. The Roush truck teams have been extremely successful operating right out of Michigan, thank you, with third and eighth place overall standings in the 1998 series, almost identical to 1997. And don't tell Roush he has to purchase his chassis, engines or other components from someone in the South. If it can be done at all, it can be done well by Roush Racing.

Perhaps this formula has been the secret to the success of Roush's NASCAR teams over the last few years. (Roush Racing campaigns five Winston Cup and two Busch Grand National cars, in addition to the trucks.)

Part of the credit, however, must be given to the vast amount of technology used in this operation. Everywhere I looked I saw laptop computers used for reference and data recording. Nothing is left to human memory or the possibility of miscommunication.

The Teams

The two truck teams consist of the No. 50 Grainger Ford, driven by Greg Biffle, and the No. 99 Exide Battery Ford, now piloted by Mike Bliss for 1999.

I was given a shop tour by Matt Chambers, Crew Chief for the No. 99 truck and Randy Goss, Crew Chief for the No. 50 truck. I asked them what it was like, working in close proximity to another team.

"The two teams eat their lunches together and share information and communication. It keeps everybody together," said Goss. "It's an advantage."

"Randy and I work together closely, comparing notes and finding out what works and what doesn't," Chambers added. "It saves us a lot of time." Chambers prefers working in the NASCAR Truck Series rather than the Winston Cup or Busch Grand National cars. He's been on Winston Cup and Grand National teams and thinks the trucks are the best, "especially here with Roush. This is the best team I've been on," he continued, "and I find it's a lot of fun. In Winston Cup, there's tremendous pressure to please sponsors. We know we still have to make them happy,' but the pressure doesn't seem as bad in the Truck Series. We're also very fortunate to have great sponsors, as well as great ownership."

"We still have fun," Goss chimed in. "We race hard and take it seriously, but we still enjoy ourselves. Plus, when we leave home, we know we've got a chance to win. Some teams can't say that, and it takes all the fun out of it."

The huge facility is large enough to house both teams, with plenty of space for several built-up trucks, plus the offices and fabricating and storage areas. There's even a "wall" area for practicing pit stops. Each team has bays to work on five or six trucks that are in various stages of completion. Located in the fabricating area is a machine shop, a shop where oil pans and coolers are made, a shop for making headers, a chassis-building section and a shop to create the steel body shells. Outside, the transport trucks for each team wait to be loaded for the trip to Homestead.

Technology Abounds

I visited with Kevin Caparella, an experienced shock man who builds the shock absorbers for both teams. He creates a computer profile of each track on the schedule, compares it to last year's results and prebuilds the shocks for each truck accordingly. Caparella says short tracks with higher banks, like Bristol, create his biggest problems, because "a lot is happening in a short distance"-lots of bumps and turns. He then prepares several sets of shocks for each of the two trucks, which can then be fine-tuned at the track during testing and qualifying.

Caparella logs the mileage of each component and records the changes on his laptop computer. He inspects the shocks after every race and rebuilds them after three races. He uses a dynamometer that's specially made for testing and proofing the shocks before returning them to action. Again, the dynamics of each shock are recorded on his laptop for later reference.

Brian Hoye builds the transmissions and differentials for the truck teams. He has 22 Jerico four-speed gearboxes in his inventory and prebuilds several boxes prior to each race. Hoye usually prepares a tranny and two spare boxes for each truck, while the parts truck hauls two extra units, just in case. Having eight transmissions for the two trucks gives him the flexibility to rebuild quickly at the track to suit the driver's needs.

Eight-axis CNC turn/mill machines—EMCO Maier, booth A-8540 - Turning Equipment - advertisement - Brief Article

The Hyperturn 645/665MCplus, an eight-axis CNC turning-milling machine with Y and B axes is said to feature an crgonomically designed work area with straight chip drop, fully covered guideways and optimum lighting. According to the company, both dynamic spindles are powered by integrated spindle motors with synchronization and have a wide speed range, high torque and high drive power. The main spindle also has a bar capacity with a maximum diameter of 45/65 mm. The 12-station, upper tool turret Y axis and B axis (Quickmill or Powermill) have 12 driven tools and are for use on both spindles. The lower tool turret, which is also used on both spindles, features VDI quick-change system, 12 driven tools and alignment-free toolholders. The machine's control is a Sinumerik 840D with LCD color monitor.

This B-axis configuration of the Hyperturn QuickMill allows the upper turret to swivel to any position within a 45-degree arc. The combination of axial holder, radial holder and 45-degree holder can reach any angle within a 180-degree range. Its tool-change time is 0.14 second.In the configuration of the Hyperturn Powermill, a milling spindle with hollow-shaft motor takes the place of the upper turret. The B axis travels 210 degrees. The tool carrier is a 24-tool station magazine with Capto-C4 holders (48-tool stations optional). The Y axis of the machine is designed to divide the cutting forces over two guide planes. The result, the company says, is rigidity for all turning and milling operations. Travel of [+ or -]50 mm permits off-center milling and drilling. The company will show examples of its machine tool line. Some additional models on display include the Hyperturn 690 and Emcoturn 325-II.

CNC needs CNC support - computer numerical control machines

Outdated secondary-operation machines were strangling the productivity of a Chicago-area screw machine shop's impressive battery of CNC screw machines. Now, CNC drilling and tapping machines and turning centers are providing secondary machining efficiency that has raised the firm's performance to a level few competitors can match.

When you drive past the building, with its concave front and narrow, close-set, floor-to-ceiling windows, you would guess an insurance firm, or an engineering or architectural firm, or perhaps an association office. In fact, the distinctive exterior pictured in Figure 1 houses the operations of General Automation, Inc., one of the most impressive screw machine shops in the country.

General Automation specializes in, among other things, Swiss screw machine parts, that is, workpieces with high length-to-diameter ratios. The firm produces them on numerous Swiss-type cam automatic screw machines, arranged like spokes on large wheels, bar feeds toward the center. (The arrangement makes the most efficient use of floor space and makes it easier for the operators to load the machines and tend their operation.)

Although cam-operated screw machines have been around for generations, they remain a very competitive method for producing workpieces in large quantities. They can produce workpieces in less time (a shorter cycle) than by most other methods.Screw machine shops are aware of the advantages of CNC screw machines; many have one or two in order to remain competitive on prototype work, short run jobs, and jobs where fast turnaround and/or high quality are critical. However, few shops are in a position to invest in enough CNC screw machines to comprise a separate department.

General Automation is one of the few. The firm operates some 63 Nomura CNC Swiss-type screw machines--the largest concentration of such machines in the U.S. The CNC Swiss-type screw machine offers a number of advantages over the older cam automatic screw machine. As its name implies, the cam automatic's cutting tool movements are controlled by a set of cams specially made for the workpiece being produced.

The CNC screw machine needs no cams. Tool movements are automatically determined by data from the dimensions of the part, fed into the machine's CNC unit. The workpiece can be programmed on the CNC right at the machine. Or, as is more often the case, the program can be prepared on a programming system located off the shop floor, and loaded in the machine's control when required. The control's "memory" is capable of storing dozens of workpiece programs; preparing the CNC screw machine to produce a different workpiece simply involves calling up the program for the next job, minimizing machine downtime between jobs.

Because CNC machine tools handle job change-overs much faster than manual or automatic machines, they are usually thought of as "short-run machines." By contrast, cam automatics, which are noted for their very rapid cycle times, are considered "production machines," ideal for producing large quantities of workpieces over long periods of time.

However, General Automation's CNC screw machines are faster than its cam automatics, so the company benefits not only from fast, easy machine setups, but from fast workpiece cycle times as well. According to General Automation president Max Starr, the CNC Swiss-type machines are frequently the most economical choice for complex workpieces, regardless of the length of the run.

Other advantages of the CNC screw machines are their greater accuracy and piece-to-piece consistency. Both are important to today's product manufacturers who demand parts machined to finer dimensional tolerances--and that those parts be within tight statistical process control parameters.

Another big advantage of the CNC screw machines--important to any job shop concerned about controlling costs--is that operator responsibilities are reduced to monitoring the machines and keeping their bar feeds filled. This enables General Automation to use less skilled operators at lower hourly rates.

Plugging into STEP NC - Emphasis: CNC - CAM software firms offer programs for CNC machines

CAM software companies are offering software programs that allow their users to read STEP-NC files info their existing CAM software to generate the tool path and output for specific CNC machines. These "plugins" make many of the benefits of STEP-NC available to the average machine shop today.

The concept behind STEP NC is simple. It enables a product model database to serve as direct input to a CNC machine tool. No separate files of tool paths. No G or M codes. No post processors.

This is a radically different approach to CNC programming. It has far-reaching implications for the emerging possibilities of "e-manufacturing." Recent developments, however, promise to make it easier for CNC machine shops to make the transition to this technology Without scrapping existing machine tool and CNC programming technology, shops now have a way to implement key aspects of STEP-NC.

Several leading CAM software companies have made it possible for STEP NC files to be used with their own software. This makes their users ready to participate in supply chains that are turning to global data exchange standards to streamline the flow of digital information over the Internet. According to STEP Tools, Inc. (Troy, New York), a leading supplier of STEP software toolsets for application software developers, design firms and manufacturing companies, STEP NC offers significant savings to machine shops and their customers. The company estimates that, by fully implementing STEP NC, machine shops can reduce the time it takes to get jobs onto their machines by 35 percent if they can seamlessly read the 3D product geometry and manufacturing instructions of their customers. Likewise, original equipment manufacturers can reduce the time they spend preparing data for their suppliers by as much as 75 percent if they can seamlessly share the design and manufacturing data in their databases.

STEP Tools also estimates that STEP NC will reduce machining time for small- to mid-sized job lots by as much as 50 percent because STEP NC compliant CNC units will be capable of optimizing speeds and feeds with very little intervention from CNC programmers or machine operators. This factor could make it easier and safer to program high speed and five-axis machines, the company says, making it more likely that they will be used for small- to mid-sized job lots.

STEP NC In A Nutshell

STEP NC is an extension to STEP, the STandard for the Exchange of Product model data. STEP is the international standard that specifies a neutral data format for digital information about a product. STEP allows this data to be shared and exchanged among different and otherwise incompatible computer platforms. STEP NC standardizes how information about CNC machining can be added to parts represented in the STEP product model.

By using STEP NC to capture instructions on what steps to follow for machining the part, the "producability" of this part would not be affected by the availability a certain brand of control unit, programming system or post processor. Figure 1 compares the key features of STEP NC to current conventional approaches to creating CNC machine tool input.

If equipped with a STEP NC compliant CNC, any suitable machine tool could be designated to make the part. Because a product model database can be made accessible through the Internet, this designated machine tool could be linked to this global network virtually anywhere on earth. For manufacturing enterprises participating in a highly competitive global supply chain, this kind of flexibility is crucial. With the Internet acting as a global DNC system, the world becomes one big job shop.

Step Rather Than Leap

The availability of STEP NC software plug-ins for CAM software puts STEP NC within the reach of many shops. Currently, plug-ins are available for Gibbs CAM from Gibbs and Associates (Moorpark, California) and for Mastercam from CNC Software (Tolland, Connecticut). A plug-in for Esprit from DP Technology(Camarillo, California) will be completed soon. With these plugins (or "add-ins," as they are also called), a shop can take in a customer's STEP NC files and produce parts on existing CNC equipment.

A full implementation of STEP NC would involve equipping machine tools with CNCs customized with special software. This software enables the CNC to interpret the STEPNC data directly and use the information to machine the part without a conventional G-code program. This software is currently under development.

Machine tools with PC-based open architecture control systems may be able to install this software to upgrade to STEP NC compatibility rather effectively. The conventional input/output (I/O) structure and the servo system of the CNC machine do not need to be modified under STEP NC.