Shop Solutions: Skills Champs Train on Peanut Butter
It was just like any nightmarish day at a typical US high-tech manufacturing plant. Give a team of trusted workers eight hours to accomplish what could easily take ten or fifteen, then half way through the day, throw in a curve ball change order that requires them to back track and redo work they have already completed.
That's exactly what a team of three students from the Orleans/Niagara BOCES (Board of Cooperative Educational Services) Technical High School (Sanborn, NY) had to overcome to take first place honors in the National Skills USA Automated Manufacturing Technology Competition last year in Kansas City, MO.
The team was competing against regional championship teams representing 43 states as well as Guam, Puerto Rico, and the Virgin Islands. The competition was all over in a day, but it took months, actually years, of preparation.
Scott Brauer, director of the Orleans/Niagara BOCES machine shop program since 1997, brought a lot of insight to preparing students for the real world of machining when he switched fields from industry to education. He had been supervisor of a 100-man milling department for a local manufacturer.
"I was hiring kids and firing kids out of the same program because they were not prepared to go to work. I came here to update and upgrade the program and get the kids ready to work," says Brauer.
One of his first goals was to modernize the equipment at the facility. He upgraded the manual equipment first, then used his industry contacts to find companies willing to provide a deep discount on excess CNC equipment or even donate it for a tax write-off.
Another objective was to begin to change the perception of the Orleans/Niagara BOCES program at the six high-school districts that feed into it. Brauer began visiting the schools and talking to counselors about the program. "You know this isn't a dirty, stinky trade any more," Brauer would say. "In most shops you would eat off the floor sooner than you would eat off the gym floor."
By changing the look of the program, adding new equipment, and then winning some regional manufacturing contest victories, the program was reborn. It went from barely having enough students to sustain half-day sessions to an overflowing fall enrollment for two sessions a day. All that happened the first year.
Since then, the BOCES program has been well balanced with two sets of 15 students attending sessions in the morning and afternoon. Brauer says the two hours and forty-five minutes he spends with them each day is more than they spend with any other adult in their lives, including their parents in most cases.
The BOCES program teaches critical thinking and essential modern workplace skills, starting with the very basics. Students will ultimately learn to program CNC mills and lathes to manufacture complex parts using advanced CAM software. However, before they do it the easy way, they have to master the basics of writing their own G and M-code machining programs, so that they fully understand why and how high-tech automated manufacturing equipment does what it does.
To understand that equipment is dumb and won't do anything unless you tell it to, Brauer gives new students a lesson in making a peanut butter sandwich. "I don't have anything on top of my desk and I have them write down everything they want me to do to make their sandwich as a sequence sheet. Then I do everything exactly the way they tell me to do it," Brauer explains.
"If they don't tell me to get the bread out, I just stand there and look stupid. If they don't tell me to take the twist tie off the bread, I don't know to do that. They might say spread the peanut butter, but they never say get a knife, so I just dig my fingers in the peanut butter and spread it. If they don't say spread it on the bread, I spread it on the table. It's a fun afternoon in the class," he says.
The deeper meaning of this lesson, which the students will never forget, is the care and attention to detail required to write a good CNC machine program. "And it works great, because they get to eat a peanut butter sandwich, too," Brauer adds.
With this lesson under their belts (so to speak), the students are in the right frame of mind to begin learning CNC machine programming, progressing from basic to advanced CNC programming. Students will learn to be proficient using software that is most commonly used by nearby manufacturers—not only the latest versions but also previous versions, so they are prepared for whatever they find in the workplace.
All of his kids are capable of going to competitions on the state level and doing well. That's why Orleans/Niagara BOCES has won the state competition all but one of the last six years. However, the group of students that represented Skills USA nationals in 2006 were chosen to compete for Orleans/Niagara BOCES because they worked harder than everyone else.
"They took it home with them," Brauer says. "Or they'd say 'Brauer, can we stay late tonight?' So we would stay until 7 or 8 o'clock at night. Those kids are self-motivated. They will be the ones who will be owning shops. Instead of making payments on a souped up car, they will be paying for a CNC machine in their garage, and making $20,000 off the machine. That is literally happening with some of my students right now."
Students are encouraged to take personal ownership of everything they are involved in. A good example of this occurred in April after the students had won the state competition one more time and were preparing for the Nationals.
Brauer trusted his students to choose the CAD/CAM program they would be using. To that point it had been Mastercam ver. 9 from CNC Software Inc. (Tolland, CT). The local Mastercam representative suggested they would have a better shot at winning with Mastercam X. Brauer acquired a demonstration copy and immediately handed it over to the team so they could make their own evaluation.
This was not a trivial decision. It sounded as if there would be many features in the program that could make the students much more productive. On the other hand, the students had received no instruction in the program. They would have to pick it up on their own. If the learning curve was too steep, there was a chance that changing software just before the competition could slow them down.
The new version of the software, Mastercam X, turned out to be very different from what they had been using but it did not intimidate the skills team. "Literally within one class period, the kids were in love with it. They were sure it would give them an edge because it rapidly imported CAD files that didn't have to be cleaned up afterwards, and because all of the programming tools they use most frequently could be arranged in pallets just a click away on the desktop," Brauer says.
"There was no way they were going back to version 9 after seeing how efficiently they could operate in X. They insisted that I buy it for them before the national competition. So I did," he says.
Armed with a new CAD/CAM package they had learned on the fly, the Orleans/Niagara BOCES Team hit the floor of Skills USA eager to compete. Seventeen thousand spectators were on hand to watch 84 different competitions on an auditorium floor about 11 football fields long and seven wide.
The team consisted of Krista Kelly, the CAD person, who created the part design from a quick sketch given to her by the judges. Nick Alitzer, the CAM person, brought in the part geometry from CAD, tweaked the design, and created the cutting tool paths. John Stuart, the CNC machine operator, who also served as the team leader and communicator between the team and judges, performed all the paper work associated with the manufacturing process.
During the day, responsibility for the next critical step in the process shifted back and forth from one team member to another. All the while, the other members took care of essential details that would move the entire process along later on.
"These kids literally worked their butts off the entire time," Brauer says. "They probably got 80–90% of the way through the original task when they were given the revised piece (the curve ball change order). Then they got all the way through that. They had to do a lot of problem solving."
When it was all done, three of 46 state champion teams were standing on a platform. The team from Orleans/Niagara BOCES was in the middle, each smiling member with a gold medal around his or her neck.
Flexible Deburring for Aluminum Die Castings
Flashing on die-cast parts must be removed for operational, safety, and aesthetic reasons. How this chore is accomplished has always come under considerable scrutiny by manufacturing engineers and, more importantly, by Occupational Safety and Health Administration (OSHA) regulators.
For sister Ligon companies, TPi Arcade Inc. (Arcade, NY) and Harmony Castings LLC (Harmony, PA), automatic deburring tools that can work with robotic systems are reducing processing time as well as programming time for robot-held deburring tools.
Harmony Castings and TPi Arcade provide a number of casting services specializing in aluminum V-Process manufacturing. Some of the parts produced for their customers include engine cases, primary covers, and tranny covers for Harley Davidson; alternator housings for Delphi Automotive; snowmobile drive covers for Polaris; and engine oil pans for John Deere, among others.
Manufacturing using the aluminum V-Process is done on state-ofthe-art, computer-controlled equipment to produce castings with finer finishes and tighter, more consistent tolerances. The V-Process provides quick turnaround and high-quality castings that are well-suited for prototyping and low-volume applications.
Some of the advantages of the V-process include:
- Zero-degree draft, which reduces weight and minimizes post-cast machining,
- Ability to maintain thin wall thicknesses of 0.125" (3.2 mm) over large areas and 0.09" (2.3 mm) in small areas,
- Produces tight tolerances as much as twice as accurate as sand casting,
- Results in unlimited pattern life,
- Finishes of 150 RMS finish as compared to 250–550 for sand cast and 200–500 for permanent mold, and excellent molding integrity maintaining repeatability of all casting dimensions.
"With the new, patented Flexdeburr tool we have cleared the hurdle, cutting the deburring time in half and minimizing employee involvement," explains Tom Wittmeyer, TPi Arcade process technician. "The automated tool allows us to robotically remove the flashing quickly and efficiently, while virtually eliminating the operator's manual deburring and exposure to casting dust."
The Flexdeburr RC-660 tool is provided by ATI Industrial Automation (Apex, NC). "We have always looked for ways to implement robots to perform these routine and repetitive deburring tasks," says Wittmeyer. "However, we were somewhat restricted when programming the robot. Typically, robotic programming moves the deburring tool along a path defined by discrete points, and that path may not exactly coincide with the shape or contour of the surface to be deburred due to variations in the part itself, or to differences between the part edge and the exact path the robot has interpolated."
Problematical burrs, residual material on parting lines, and flashing on die-cast parts must be removed for operational, safety and aesthetic reasons. Traditionally, manual deburring operations using hand-held tools were used, but they lead to several health and safety problems, such as Carpal Tunnel Syndrome and white fingers (permanent numbness) when workers are subjected to constant vibration, high contact forces, and the required contorted positions characteristic of hand-held deburring tools. Metal, fiberglass, and other hazardous particles introduced into the workers' environment also pose health risks. In addition, the tedious, manual deburring task often results in inconsistent finished-part quality.
Implementing the Flexdeburr has addressed these problem areas. The patented flexible deburring tool utilizes a unique pivoting motor and spindle arrangement that provides radial compliance that accommodates differences between the part edge and the actual toolpath. The tool is designed to follow the part profile, accommodating surface variations.
Wittmeyer explains that when the aluminum casting comes out of the V-Process there are minor flashings that need to be removed. "We use ATI's Flexdeburr model RC-660 mounted in a stationary position, and a robot to maneuver the part for deburring. We started running the VProcess in 1979 and all of the deburring operations were done manually until we implemented the Flexdeburr a few years ago.
"Our first installation of Flexdeburr resulted in a 90% reduction in deburring operations, and an overall bench-time reduction of 60%. Also, the reduced deburring time significantly lowers the employee's exposure to aluminum dust and other contaminants. This initial success has convinced us to look at other applications that can benefit from robotic-finishing operations."
Robotic deburring has enabled manufacturers to replace manual deburring processes with a sufficiently accurate automated alternative. Robotic deburring and chamfering have typically been difficult to perform with the required degree of quality. The complexity of the part and the robot's inability to generate a path exactly equivalent to the part edge make it difficult for the deburring operations to meet overall quality goals. Also, programming of robot movements depends on the complexity of the part, and complex parts require significant programming time to achieve acceptable robot paths. ATI's Flexdeburr tools were designed to overcome these difficulties and improve deburring quality while reducing robot-programming time.
The Flexdeburr tool is a patented high-speed, air-turbine-driven tool for deburring aluminum, plastic, steel, and other materials, even in tough to reach places. While spinning at high speeds, the lightweight, rotary tool has radial compliance supported by air pressure applied to the shaft, allowing the tool to perform consistently on irregular part patterns. The pivoting motor-and-spindle arrangement provides up to ±0.31" (8 mm) of radial compliance, and maintains a constant deburring force.
Flexdeburr tool is said to satisfy nearly 100% of all robotic and automated deburring applications. Mounted to a robot or CNC machine, its air turbine motor requires clean, dry, filtered, nonlubricated air that can be directly vented into the workplace. High stiffness from its pneumatically adjustable feature minimizes chattering, a common problem in robotic deburring. Deburring can be as fast as 1–3 ips (2.54–7.62 cm/sec) on hard materials and 3–12 ips (7.62–30.5 cm/sec) on soft materials.
The inherent compliance at the deburring tip saves robot-programming time. Programmers can program fewer path points, because the tool compliance will accommodate deviations between the robot path and the part profile. The robot path does not have to precisely follow the part edge. Programming savings are multiplied in applications where multiple passes are necessary to achieve a desired finish.
Process Meets Customer Demand
Meeting customer requirements in a timely manner is critical for manufacturers, especially when the customers are no longer willing to accept lengthy lead times or to pay for an increased level of service. To ensure continued success, manufacturers must reduce turnaround time through increased efficiency, while reducing or maintaining current cost levels.
For one New England manufacturer, the solution to this challenge lies in constantly improving its processes. Founded in 1982, Robohand Inc. designed and built the world's first intelligent sensorized gripper. Today, the company is known as De-Sta-Co Robohand, a division of De-Sta-Co Inc. (Madison Heights, MI), which manufactures clamping, gripping, work transfer, and robotic tooling solutions.
Every major component of the company's wide variety of grippers, actuators, slides, escapements, tool changers, and other modular automation components is produced in a 16,800 ft2 (1560 m2) facility in Monroe, CT.
In recent years, the demand for quicker turnaround has grown substantially. "Customers have gotten to the point where they need products yesterday," says Chris Grohe, manufacturing manager at De-Sta-Co Robohand. "As recently as five years ago, if a customer had an order, a two-week delivery time was acceptable. Today, if you quote a delivery time of two weeks, there's a good chance your customer will be looking to your competition. They simply can't afford to have their operations slowed by the fact that they can't get a part they need," Grohe explains.
Traditionally, manufacturers have turned to inventory systems to increase their responsiveness to customer demand. This action has the unfortunate side-effect of adding to the complexity of an organization. Additionally, maintenance of an inventory system adds to the overall cost of operations.
"Somebody has to pay for inventory, and that somebody is the business maintaining it," says Grohe. "Because of the variety of products we offer, there is substantial cost to stocking a large surplus of parts. Keeping an inventory of this nature means that we would have money sitting on the shelf instead of being reinvested in new technology."
To ensure that the minimum of inventory is necessary, De-Sta-Co Robohand has focused heavily on keeping abreast of technology that provides maximum flexibility and productivity to its operations. In recent years, these efforts have led the company to move a substantial amount of production to HMCs, as opposed to the VMCs that had long been used. This shift has increased the responsiveness and efficiency of operations.
As part of the evolution of its processes, De-Sta-Co Robohand expanded its horizontal machining area by investing in two Mori Seiki NH4000 DCG HMCs in 2005. As work moved from VMCs to the new machines, the value of the investment became apparent.
When De-Sta-Co Robohand purchased the NH4000 DCG machines, it opted for the largest possible toolchangers. Each machine is set up to handle a designated family of parts, with all of the tools necessary for each component stored in the toolchanger. The company also designed its fixtures to accommodate this strategy. As a result, the machines can move from part to part within the same family in 15 min of setup time.
The use of horizontal machines greatly reduces the number of required setups. For instance, one of the NH4000 DCGs is dedicated to producing aluminum bodies for Robohand parallel wide-body grippers. The parts require line-boring of four shafts, along with several other secondary machining operations, all of which must maintain tolerances of 0.0005" (0.013 mm). The parts must also hold a true position of 0.001" (0.03 mm) between operations.
On a VMC, one of the bodies would require six different setups and a total machining time of 45 min. When moved to the horizontal machine, the part could be completely machined in a single setup, and requires just 15 min of machining time. The switch provides a clear boost to productivity, and also makes it easier to hold the needed tight tolerances.
"When you handle a part five or six times, you're introducing a lot of variability into the process, which can open up your tolerances," says Grohe. "When you handle a part once, your accuracy will be as good as your machine. If you invest in quality machinery, you can be much more confident in your ability to hold very tight true positioning call outs and tolerances."
De-Sta-Co Robohand has also formalized its lean production efforts since the beginning of 2006. Multiple 5S (Sort, Set in Order, Shine, Standardize and Sustain) events have been held at the company's manufacturing facility. This lean tool involves revising the layout of a workspace to ensure maximum efficiency. The company's lean programs have also included several value-mapping events, designed to streamline production processes. These types of programs have helped ensure maximum benefit from the investment in new technology.
The flexibility introduced by the NH4000 DCG machines has helped De-Sta-Co Robohand increase responsiveness to customers. Parts are manufactured in lot sizes ranging from 4 to 48, as demand requires. The company keeps turnaround time to three days on core products, and under a week overall. In short, the switch to horizontal machining and other process changes have helped De-Sta-Co Robohand rise to the challenges posed by the market. Future changes are already being planned to maintain the company's competitiveness.
"In early 2007, we'll be receiving another NH4000 DCG, and we're including a Mori Seiki Linear Pallet Pool, or LPP, with that machine," says Grohe. "We reduced the effects of setup times by moving to horizontal machines, but the pallet system will allow us to eliminate them altogether. The LPP will provide lights out machining, allowing us to get even more out of the machine. Global competition has never been fiercer, and if we want to continue to grow as a company, our processes must continually evolve with technology."
In the areas of turnaround times and pricing, customer requirements continue to increase at a rapid rate. De-Sta-Co Robohand's manufacturing operations illustrate how these demands can be met by constantly developing better processes and investing in new technology that allows for their implementation.
Hone Smooths Rough Auto Edges
Many parties have a stake in the results when it comes to the remanufacture and rebuilding of automotive engines and machined components. The economic factors include purchase price, service life, and warranty. And, of course, the interest in competitive performance racing has never been greater.
There are other issues that are becoming more prevalent today as well. They include environmental impact, consumption of fuels and lubricants, and safety. All of those factors can be directly affected by the selection of tools used for rebuilding and servicing engines, brakes, and other wearing automotive components.
From prepping combustion cylinders to surfacing brake rotors, many automotive applications benefit from the deburring, edge-blending, and other finishing capabilities of the fast, economical, and ball-style hone.
This especially applies to the surfacing of metal finishes when honing is concerned. Use of the optimum honing tools can affect all of the above, especially when it comes to the performance and wear life of engines and vital components.
"The ball-style hone has contributed to our engines having a 0.16% warranty claim rate in an industry that averages 6–8%," says Benjamin Baloga, plant engineering manager for Tomadur Engine Co. (Industry, CA).
Tomadur remanufactures 19 different Ford gasoline engines back to OE specifications for dealerships throughout North America. The company uses Flex Hone ball-style hones from Brush Research Manufacturing (BRM; Los Angeles) to finish combustion cylinder bores and chamfers, as well as the cylinder bores for hydraulic valve lifters.
"After we are done with the diamond honing of a piston cylinder bore, there are torn, jagged metal particles partially attached to the cylinder wall surface," explains Baloga. "These are microscopic in size, much smaller than burrs. When we use the ball-style honing tool connected to an air drill, the surface Ra value [roughness average, in microns] goes from 24 to 14. And it only takes five strokes off an air drill to do that."
The ball-style hone creates a clean, partial-plateau surface finish that allows the piston rings to mate more efficiently to the surface of the cylinder wall. This ensures longer ring life.
"If the rings were installed without the ball honing, those rings would have to clip off jagged metal shards [from the newly bored cylinder walls], which would wear down the rings faster," Baloga says. "If not removed, those metal shards and particles could result in piston scuffing problems, and possibly some vertical scratching in the piston wall, which could add to the engine's oil consumption. So, by using the ball-style hone we are able to allow the rings to mate-in much more quickly, and also achieve lower oil consumption."
Baloga points out that by eliminating the potential for piston scuffing, finishing the cylinder bores with the Flex-Hone could also protect against consequential compression losses resulting from galling cylinder walls with microscratches, which could in turn cause pistons to gall. The ballstyle hone also helps Tomadur achieve the proper crosshatch finish for proper lube oil distribution.
"In the end, this simple tool helps to ensure longer engine service life with better compression and lower oil consumption numbers," he says.
Tomadur also uses a Flex-Hone ball-style hone to deburr the chamfer on the bottom of the piston cylinder bore. "On many engines, there is a sharp edge at the bottom of the cylinder bore after machining," Baloga explains. "There is the potential for piston skirt scuffing, because the piston skirt goes out past the bottom of the cylinder walls on some engines. So, we use a Flex-Hone ball-style hone to create a smooth radius at the bottom of the cylinder bore. It takes only about five seconds to do that, and it can prevent a lot of problems."
The ball-style hone is a highly specialized abrasive tool for cleaning, surfacing, deburring, and edge blending of critical metal surfaces. It is instantly recognizable by its appearance, and is characterized by small, abrasive globules that are permanently mounted to flexible filaments for specialized surfacing, including deburring, edge-blending, plateau honing, and deglazing.
Deburring operations cost American companies billions of dollars annually, and it is a production headache that frequently causes bottlenecks in production and refinishing. But in rebuilding an engine or resurfacing brake rotors or other components, deglazing is also a vital function that is performed well by the properly selected ball-style hone.
For example, rebuilders of diesel engines use the ball-style hone to clean the cylinder counterbores after removal of old cylinder liners (or sleeves). This operation is considered critical for the top O-rings to seat properly when the new cylinder liners are installed.
Cylinders are also de-glazed using the ball-style hone when engines are simply re-ringed rather than overhauled. In addition to combustion cylinder work, Tomadur also uses a Flex-Hone tool to create a blended radius on hydraulic valve lifter bores, thereby avoiding scuffing problems on valve lifters.
BRM developed the Flex-Hone for diesel-engine cylinder deglazing and finishing. The tool's design makes it well-suited for just about any application that calls for the use of a resilient, flexible, and soft-cutting honing solution. This ball-style hone's independently-suspended, abrasive globules both self-center and self-align to the bore as well as compensate for wear, all of which facilitates close-tolerance finishing work.
Picking the right ball-style hone depends on many criteria, including the job to be done, the size of the tool required, the type of abrasive used, and the grit/grade. It is for this reason that BRM custom-designs ball-style hones to meet customer specifications.
This article was first published in the May 2007 edition of Manufacturing Engineering magazine.