By Brad Branham
Rensselaer Polytechnic Institute (RPI) in Troy, New York – the oldest technological university in the United States – is well known for its heavy focus on manufacturing education and research. At least one program in its highly respected School of Engineering, however, offers students something a little out of the ordinary.
In the two-semester Advanced Manufacturing Lab (AML) at RPI, teams of engineering students are assigned a product concept at the beginning of the first semester. The course is unusual, because the students not only have to develop a manufacturing process for the product, but they also have to manufacture it.
“RPI’s AML is a class to give future engineers an appreciation of what it takes to manufacture something using the different systems available,” explains Sam Chiappone, Manager of Fabrication and Prototyping, School of Engineering. “In the first semester, the students get familiar with various processes through a series of lab exercises, such as CAD/CAM, robotics, plastics – the tools they need to design a manufacturing system.
“In the second semester,” Chiappone continues, “students work through the manufacturing and assembly process directly, under the supervision of AML Systems Engineer Larry Ruff. They build a prototype manufacturing system to produce a product within budget, and within a 14-week timeframe. THAT’S PRETTY INTENSE.”
Chiappone notes that AML is popular with students from all majors, even those who do not pursue manufacturing as a career. “It is important for all young engineers to think about manufacturing,” he says. “That forces them to think in terms of optimization, efficiency, and process.”
One recent team of student engineers not only developed a successful manufacturing system, but also won the ASME Student Manufacturing Design Competition with their effort.
“We were assigned to produce a small M1A1 Abrams tank – a model or a toy,” explains Team Leader Alexander Weisser. “We had the use of the Haas Technical Education Center (HTEC) to produce the product, so we decided to build something between the two – not to scale or as detailed as a model tank, but something more than a toy.
“During the AML first semester,” says Alex, “we designed the tank and did the market research. We developed our own CAD models, our own ideas, and eventually a manufacturing plan. By the end of the first semester, we had all the CAD models completed, and even a few prototypes.
“Halfway through the second semester,” he continues, “we had the codes set up, the fixturing done, the molds made, and we were ready to start production – and ready to handle any issues that developed. Our 15-member team produced 400 tanks by the end of the semester, complete with packaging that we also designed and produced.”
The RPI team decided to machine the main tank bodies out of aluminum, and use injection-molded ABS plastic for most other features. Brian Bidwell was the manufacturing manager and CNC programmer/operator. “I used Mastercam® X3 to write G-code for the Haas VF-1 machining center,” Brian recalls. “We chose 6061 aluminum for the tank hull, as well as for the mold cavities for plastic injection molding, and other tooling that required precision machining.
“The tank hull was machined from a billet using solid carbide end mills with ZrN coating for high-speed machining,” Brian continues. “And we utilized the Haas VF-1’s 4th-axis rotary table to minimize work setups. The tanks had many angles and tiny details that required a lot of thought and creativity to produce.”
Tiffany Hu, the team’s financial manager, also worked on the plastic injection molding for the side armor, turret, two different types of wheels, and other components, using molds created on the Haas VF-1. “The wheels were run using a Battenfeld injection molding machine,” she explains, “using 3″ x 3″ molds with cavities for four round wheels and one spur wheel per shot. We needed 9800 good parts.”
Nick DeMartin was the assembly manager for the M1A1 Abrams tank project. “I was involved with planning the assembly process, as well as seeing it through to completion,” he says. “We assembled the turrets using an Adept 4-axis robot manipulator to position the pieces, and a heat-staking tool to weld them together.
“Each tank had 9 axles and 18 wheels,” Nick explains. “We produced 400 tanks; that’s 3600 axles and 7200 wheels. We used a combination of a toothpick-dispenser-style axle feeder and a linear-bearing fixture controlled by a Staubli 6-axis robot with a custom-built end effector [sensor]. The treads and turret were assembled by hand, and the side armor pieces were attached using a press.”
The RPI team worked its way through several real-life manufacturing problems, solving them with reason and ingenuity. They changed process timing, developed custom sensors, and designed assembly fixtures to successfully address some complex issues.
After production, they concentrated on making a presentation for the ASME manufacturing contest, including full descriptions, numbers, explanations, and processes. Finalists in the ASME Student Manufacturing Design Competition must make an oral presentation describing their project (with exhibits) to a panel of industry experts. Then, they must be prepared to answer tough questions at the annual ASME/Manufacturing Engineering Division Conference.
“We cataloged every aspect of the process,” Alex recalls. “We wanted to document all the information necessary to set up another assembly line in a different location. Eventually, we used that data to enter the ASME Student Manufacturing Design Competition in the Manufacturing Systems Management and Optimization category.” Alex traveled to Oregon State University to make the contest presentation for the RPI team project – and won!
The RPI AML Tank project partnered with local industry to help with the materials and other requirements of the undertaking. Project sponsors Ensign-Bickford Aerospace & Defense Company, LoDolce Machine Co., RBC Bearing, Covidien, and Haas Factory Outlet-Allendale provided the support that helped them achieve their success.
“Working on the M1A1 Abrams tank for AML provided great hands-on experience for students with an interest in manufacturing,” says Tiffany. “The knowledge gained from this series of classes was applicable to real-world situations, and gave me great preparation for a manufacturing-related job, post graduation.”
“I am very proud,” adds Nick. “I’m proud of how the tank turned out, and I’m proud of our finish at the ASME contest. But more than anything, I’m proud of my team.”