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Shop Solutions: Focus on Automated Five-Axis Machining


A strong sense of mission and a firm focus on five-axis machining and automation have propelled Turbocam Automated Production Systems (TAPS; Barrington, NH) into a leadership position globally in the high-volume production of machined impellers and blisks from wrought alloys to replace cast components.

TAPS is a division of the Turbocam Group, a turbomachinery parts manufacturer with the capacity to produce 250,000–300,000 impellers a years from wrought aluminum, stainless steel, and titanium. It owns designs for some 400 unique bladed parts for compressors, blisks, turbines, and pumps.

Once a visitor reads Turbocam's mission statement, it's obvious that this is a different kind of company, founded by a man of deep religious conviction and commitment to satisfying the needs of its customers through integrity in its practices and personal relationships.

The man who wrote that mission statement is the founder, CEO Marian B. Noronha, a native of India who studied aerospace engineering and immigrated to the US in 1979. Noronha had a keen interest in energy conservation and focused his avocation into the study of wind technology, volunteering at a windmill company in Vermont in the hope of one day becoming a paid employee. The company hired him, but shortly thereafter the US was plunged into an economic recession and within a year he was out of a job.

Noronha wasn't a US citizen yet, and therefore had difficulty landing a job, particularly in the aerospace industry. He ultimately secured a position writing software for a CAD/CAM company, and two years later, in 1983, started his own company.

"I knew very little about machining, and in 1985 I received a very difficult job assignment to make a prototype turbocharger," says Noronha. "I bid one month's pay on the project. Three months later I was still struggling with it. I was renting time on a five-axis machine. No one told me it was impossible and that no one else in the world could do it, so I didn't know any better. With God's help and tenacity, I finally figured it out."

Over the years, he became a specialist in turbomachinery parts, and so named the company Turbocam. By 1989 he had five employees and a small shop of mainly five-axis Bostomatics.

Jump ahead 17 years and the company now employs 225 at seven locations around the world, and is renowned for its quality, fair prices, and exemplary business ethics among automotive and aerospace manufacturers. Among its employees, most of whom are salaried, it's regarded as the company from which they will retire.

"Loyalty is unmatched here," says Noronha.

The company is completing its move into a new world-class, energy-efficient 110,000 ft2 (10,219-m2) facility on 28 acres (11.3 hectares) in Barrington, NH. Employees have managed the $5 million expansion rather than an outside builder. "That's the kind of ownership that people take here," says Noronha.

The TAPS automotive group has been producing precision parts day and night seven days a week and in untended operation on Sunday in the new facility. No Turbocam employee works on Sunday, but the machines do. At the core of the TAPS operation are 28 automated machining cells that include machine tools supplied by leading machine tool builders in partnership with Turbocam.

The newest additions to its five-axis machining capability are five cells, each of which comprises two FZ08KSM machining centers from Chiron America Inc. (Charlotte, NC). Each pair of Chiron machining centers is served by an articulating robot from ABB Inc. Robotics Div. (Auburn Hills, MI) and a 250-workpiece capacity carousel.

"We introduced the Chiron five-axis machines because of their speed and reliability," says Noronha. "Once we automated them we became extremely competitive on quality, delivery, and price for these turbocharger impellers. We make over 200,000 of these parts annually."

The driving force behind demand for the parts became apparent to Turbocam in 2002 when the EPA lowered the particulates and nitrogen oxides emissions for heavy-duty diesel truck engines—starting with the 2003 model year.

"To accomplish that, we had to make the impellers out of forged aluminum and titanium instead of cast, so that we could offer a variety of blade designs and improve the thermal properties," says Noronha. "Casting is less expensive, so we had to find a way to machine from a solid material efficiently. The trick is to go quickly, go accurately, and go reliably. The five-axis machining approach with automation is the answer."

The Chiron FZ08KSM machines used in the cells feature a chip-to-chip time of 1.9 sec or less, tool changes in 0.8 sec, feed rates of 75 m/min., acceleration to 2g, and a compact footprint of 2.3 m2.

Programming, the first step in the process, is accomplished off-line on TAPS' engineering manager Andrew Hussey's laptop. Typically, an IGES part model comes in from the customer, and Hussey checks for surface integrity, design continuity, and proper curvatures for tool and axis control, and then he recreates the surfaces in a CAD/CAM program.

"In essence, I go through several iterations as I clean up the data and make it suitable for machining," Hussey explains.

Subsequently, the program filters through a proprietary version of TruePath software from CAMplete Solutions Inc. (Waterloo, ON, Canada), which takes the CAM data and creates the five-axis toolpaths. A 3-D view ensures the run will be collisionfree and robust. The program is then electronically downloaded to one of the Siemens Sinumerik 840D controls on the Chiron machines. Hussey and Rob Bujeaud, vice president-manufacturing engineering, review the process and, if necessary, refine the program further before running the job.

In operation, the workpiece starts out as 2618 T-61 aluminum bar, approximately 4"(101.6-mm) in diam. It is rough turned on a lathe, leaving plenty of stock for processing in the cell. Workpieces are loaded onto carousels strategically positioned in the cell for the robotic handling system.

"The first function in the cell is load and unload—unload the finished piece and load the new fresh blank via the robot into the machine work area," says Hussey. "Pneumatic fixturing secures the part onto the rotating trunnion table. The Chiron begins with a roughing operation to remove the majority of the material from the plate cavities. Next it performs a finishing operation to profile the blades to a ±0.005" (0.127-mm) tolerance.

"The floor of the deck part is then milled and a fillet pass creates the geometry between the blades. All the while, the table is tilting and rotating to present the part in the proper orientation. It sounds simple verbally, but it's highly sophisticated and complex. The cycle time is proprietary, but I can tell you we are gaining 20% in productivity with the Chiron cells," Hussey explains.

The final part size is about 4 x 4" (101.6 x 101.6 mm). Laser position detectors, vibration monitors, and spindle accelerometers on the machines help maintain accuracy. Turbocam's staff engineered a special flushing and cooling system to keep the work area free from swarf, which is imperative, particularly during production at night when maybe one or two people monitor the entire production floor.

The coolant system has an added function, too. In keeping with Noronha's penchant for energy conservation, the heat is extracted and fed into evaporative coolers outside the building, keeping the building cool in the summer. For the frigid New Hampshire winter months, the captured heat warms up the offices, and melts walkways and parking areas, keeping shoveling, plowing and sand tracking into the building to a minimum.

"There are many, many creative things one can do if you aren't stuck in a particular business model," Noronha says. "It's sometimes an equation of time and money at the outset, but proven to pay back, whether it's installing new machining technology or the most efficient energy systems available, or taking care of your employees."

Since Noronha wrote Turbocam's mission statement in 1993, it has guided the company policies and its behavior as it has expanded from 25 people in 1993 to over 225 in 2006. Noronha displays the Mission Statement prominently around the plant.

"There are many ways to achieve success in business," says Noronha. "I have learned that for me in business, God comes first. God has blessed our efforts and made us a growing company with dedicated employees, loyal customers, and many suppliers who enjoy being associated with us."

        

How Riverside Measures PCD Up

Walking around its shop full of CNC grinding machines, CNC machining centers, and Vollmer sawsharpening machines, you would guess that if any company could find a way to make high-quality cutting tools efficiently, it would be Riverside Tool Corp. (Elkhart, IN).

Founded in 1989, Riverside Tool produces carbide and polycrystalline diamond (PCD) tools to shape wood and plastics and composites (including solid surface material and exotic species of wood). The company brazes the PCD tips onto cutter heads, router bits, and saw blades. Selling to distributors and end users nationwide, Riverside also services a broad range of cutting tools and manufactures insert tooling in the form of cutter heads, router bits, and custom applications.

PCD is the hardest man-made material in the world. To shape PCD tools, Riverside purchased a QWD 750H fully automatic wire EDM machine from Vollmer of America Corp. (Carnegie, PA). The QWD 750H can machine tool edges in five axes, simultaneously.

Like all high-tech machines, it is best to keep the Vollmer EDM busy producing parts, and not waiting for material or setups. Shortly after Riverside decided to invest in the Vollmer machine, the manufacturing staff made a case for acquiring a smarT check tool measuring and inspection machine from Zoller Inc. (Ann Arbor, MI).

Their rationale was that inspecting and measuring tools on the Zoller machine instead of on the Vollmer would save costly machine time for productive CNC tool shaping rather than tool checking and setups. The objective was to maximize the productivity of the Vollmer.

Riverside realized immediate cost savings in the form of reduced machine time on the Vollmer. After the installation of the Zoller, the total production time was reduced by more than 50%, because there is no need to create CAD drawings, and the profile information can be directly transferred to the Vollmer machine.

The smarTcheck features Zoller's saturn 1 vision system. It uses a 90° incident light camera with a swiveling optic carrier to measure in radial and axial directions to check parameters such as rake angle, helical pitch, land width, and other features. Cutting edges are displayed in transmitted light, permitting measurement of every tool contour parameter.

Zoller also provides software with the smarT check to measure tool characteristics such as radius, contour-cutting angle, clearance angle, chamfer width, and concentricity. Displaying cutting edges in incident light also permits close-up tool inspection to detect wear and chipping. Machine functions are controlled with a mouse or keyboard, requiring no special skills.

"The smarTcheck also allows us to fully inspect the tools we make—PCD tools as well as insert tools," says Ron Migedt, Riverside's owner. That's important because the cutting edge imparts a surface to the material, and those cutting edges need to be smooth.

"In our industry all tools are designed with hook and some with shear," Migedt explains. "So what you see on the tool edge is not what you may see on the wood. Years ago, the only way to see what you are going to get on the wood is to run a wood sample. A lot of shops today have a shaper set up to test cut parts. That's really not a very safe or accurate way to inspect our tools, simply because our guys are not woodworkers, and are not prepared to set up all the various tools," Migedt explains.

"The Zoller inspection machine, on the other hand, allows us to effectively test-cut every tool through the camera system, and duplicate what the user would see on the wood. We can then extract the resulting DXF file, and compare it to our drawing file to see how accurate the tool is. We preset all the tools, adding or adjusting shims, if necessary, on the Zoller before shipping them to the customers. If we do that and if there is minimal machine runout at the end user, the tools run perfectly every time," Migedt says. "And that's good for customer confidence and repeat business."

The lasso function of the Zoller allows Riverside to measure thousands of points on a tool within seconds, and compare actual or nominal dimensions using the best-fit and DXF interface without writing programs. Data get printed in a test log or saved for reference and quality assurance.

The smarTcheck helps Riverside assure tool quality. It also has reduced the machine time needed to produce the tools. "Because we can inspect the tools for damage," Migedt says, "we can produce a correct tool, save material, and reduce total production time by as much as 50%. With the camera, we can see any chips or damage and measure precisely how much material to remove to restore the tool edge," he points out.

"With a comparator, we would machine, remove the tool to the comparator, look at it, and return the tool to the machine for more machining. This could happen several times. And when you consider that it takes a long time to machine PCD—because it is so hard—you're talking a lot of time potentially wasted," Migedt says.

The Zoller machine has given Riverside a level of assurance with its tools before they are shipped. The company is positive the tools are within tolerance and runout, before shipping, and that even includes its insert spiral molder heads and other surfacing heads.

"It helps us ensure that each insert in a head is operating in the correct cutting plane and is in balance. Otherwise, the end user would see lines in the material, and that is unacceptable. With the Zoller we can inspect the entire cutting plane as the tool rotates in the Zoller precision spindle, and we can see if we have a section that is out of alignment. This allows us to guarantee that our tools will operate line-free in a properly qualified machine," Migedt says.

"Without the Zoller, even if you hit the machine setup numbers on the money the first time, which is unlikely, you would still take up to twice the production time without the Zoller. With the proper inspection, you can reduce the machine time to grind a tool by half. The smarTcheck helps us make better use of the Vollmer," Migedt points out.

Riverside also uses the measuring and inspection machine to document incoming tool condition, then shares that data with the customer. "With the Zoller, we inspect every tool that comes in the door for damage," he says.

"At that point, we take a picture and show the customer the proof of what we recommend. Also, if the tool needs to be reset, the operator can pinpoint precisely how much a tool tip needs to be moved or replaced in brazing."

After brazing, tools go back to the Zoller to be set up on the toolholder for all measurements and parameters to be input for the Vollmer. Tool and holder are chucked in the Vollmer, the tool edges are then machined, and the tool is returned to the Zoller for confirmation. Riverside also generates a list of the new tool measurements with the smarTcheck so the end user can input them into his CNC router or other cutting machine.

The company also uses the Zoller's tool inspection capability to reverse-engineer tooling when necessary. "A number of the tools we are asked to produce do not come with a CAD file, so we examine prototypes or older tools to be able to gather the tool profile data that we can use to produce the tools with our CNC machines," Migedt says.

        

Software Supports A Good Ride

Getting the perfect ride in a car has always been a compromise. If the suspension is stiff for responsive handling, it jars your teeth. When the suspension is soft for comfort, the car takes curves and turns like a boat wallowing in the surf.

There is a better way to eliminate this handling compromise. That's where Air Ride Technologies (ART; Jasper, IN) and its founder, Bret Voelkel, come in. Ten years ago, Voelkel, a car enthusiast, designed an air-ride system for his 1970 Mustang Mach 1. He wanted a suspension that would handle drag racing while giving him a comfortable street ride. The air-ride suspension he developed was successful, so successful in fact, that while working in his garage, he started advertising the system and began installing them on customers' cars.

Air Ride Technologies soon outgrew Voelkel's garage and eventually moved into his current building. The metal-fabricating shop grew so much that he bought the building next to it and started a body shop to do hot rod restorations and auto body work. Voelkel's three businesses, Air Ride Technologies, Concept Design and Fabrication (a metal fabrication shop), and Precision Coach Works today employ 42 people and currently occupy 28,000 ft2 (2601 m2), among all the buildings.

Air Ride Technologies produces suspension components for a large cross-section of cars. For instance, one of its new products, the AirBar, is a four-link rear air suspension that will bolt directly into OEM leaf-spring mounts of muscle cars from the 1960s without any frame cutting or metal fabrication.

The car's ride height is typically lowered by about 2" (50.8 mm). The fully deflated height is usually 5–6" (127–152.4 mm) lower than stock height. Instead of a wallowing soft ride, the car has a crisp, controlled handling. Other products include control arms, four-link suspensions, and the patented Shockwave, which is a combination air spring and shock.

The manufactured components are not the most intricate to manufacture, but designing a full suspension kit or specific components for the various vehicles can prove a challenge. Parts are usually designed to be installed without cutting or welding the car's suspension, body, or frame. Only hand-tools are needed for mounting.

Air Ride Technologies manufactures the machined components for the air springs, such as the cap that is on top of the air spring, and the piston on the air spring's bottom end. The company uses five CNC lathes and two VMCs to machine the aluminum parts. The primary rubber components for the shocks and struts are produced by Firestone.

"I would say 80% of our parts are aluminum; 20% are steel," says Beau Anderson, CNC-machine-tool computer programmer. "Some of the components inside are steel, such as the shaft that goes through the shock, but the majority of it is 6061 T6 aluminum. We have four or five varieties of caps and pistons, depending on which air spring is used. A majority of our milling work is aluminum also."

Steel parts produced from 1018 steel or tubing stock include bushings and sleeves for the four-link suspension system. Parts produced using the lathe are about 4–4.5" (101.6–114.3-mm) diam, and roughly 1 ¼" (31.7-mm) long, while the pistons are 3" (76.2-mm) diam and 3–4" (76.2–101.6-mm) long. Bar feeders can handle stock from ¾ to 2" (19–50.8 mm) and from 1 to 3" (25.4–76.2 mm).

"I won't do anything under 200 pieces with a bar feeder because of the setup time involved," says Anderson. "On the caps and the pistons I usually do about 500 pieces per lot, which is about our smallest run. We probably do about 1000–2000 pieces on some runs."

On its mills, ART sets up parts to do multiples using dedicated fixtures or vises that can handle numerous parts. Most of their parts are simple to produce, but they use a C axis on one lathes to etch the company's logo onto the strut/shock cap.

"We'll etch our logos onto the caps, so that's somewhat intricate, and some of the parts have tight tolerances. Because these parts aren't that long and you're not holding onto much stock in the lathe, we have to watch how fast they're turned, the feed rates, and how much stock is taken off," Anderson says.

Component tolerances are tight for some parts, anywhere from 0 to ±0.002" (0.05 mm), but others have a tolerance of ±0.005" (0.12 mm). On average they hold ±0.005 (0.12mm) on most of their parts.

For programming toolpaths and fixturing, Air Ride chose Mastercam CAD/CAM software from CNC Software Inc. (Tolland, CT). "After the parts have been researched, developed, and drawn up, they'll be brought to me in a print form, and I'll program them in Mastercam and download them into the CNC machine," says Anderson. "Then I'll set the machines up and produce the workholding fixtures also using Mastercam."

Programming a part's toolpath can be tricky when the C axis on a lathe is used. Anderson says that Mastercam X (the latest Mastercam version) lathe software has made it simple. Mastercam's ease of use was evident when Anderson joined the company and started using it by trial and error after a few lessons from another programmer at the company. Later he took the Mastercam Mill class, C-axis classes, and lathe lessons.

Another feature that Anderson likes about Mastercam is its ability to make changes. "If you know how to write longhand, you can go to the machine tool and make simple changes off the G-code that Mastercam uses, which is helpful." Anderson also likes the Backplot function, because it gives him an estimated amount of time to produce a part. "It allows us to try different things with toolpaths to make the part faster, if you think you need to run the part quicker or need to make a better time with it. The Verification function is great too, because if you have any possible crashes, it will show them.

Sometimes Anderson will use the Backplot function to help price a part. "If we haven't actually built the part, just prototyped it, and we need to estimate it, we will use Backplot to get a rough estimate of how long it's going to take to machine it. We might add a little bit to the production time just for tool changes, and for loading and unloading the part into the machine."

Anderson also uses Mastercam to help build the fixtures for the parts. "I just did a fixture for one of my parts, and it was nice to go from my jig back to my part and merge them together to make sure that once I made my jig and part program, they would fit together," he remarks.

Air Ride is constantly adding new car models, street rods, and hot rods to their part roster. Each vehicle will have a different bushing or cross shaft that will be used to mount the suspension system to the car.

 

This article was first published in the February 2007 edition of Manufacturing Engineering magazine. 


Published Date : 2/1/2007

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