Rick Denny started working in a shop in 1965, and learned NC programming in 1970. Moving forward, he worked at large and small job shops, in machining, engineering, and management, never straying from NC programming. With experience from shop floor to front office, he launched his own company in 1994, recruiting stepson Mike Andersen as equal partner. A home equity loan funded the start-up, enabling the purchase of a Fadal VMC. “Then we rented enough space from another shop to have two feet on either side of the machine,” says Denny, “and we took the plunge, to create Blue Chip Engineering.”
Autodesk Mechanical Desktop model of the sphere and ripple pattern supplied by Tom Shannon. GibbsCAM imported the model, which Blue Chip used to develop and program toolpaths.
Initially, Denny worked part time, while Andersen worked full time, gaining the experience that enables him to run the shop today. Within a year, the duo built a rotary axis for the Fadal, and began to build their chip-making arsenal. By 2003, the company included 20 employees and 10 CNCs, including two 5-axis VMCs, one lathe, and a programmable CMM, all housed within their 4,600 square foot facility in Ramsey, Minnesota, just northwest of Minneapolis.
From an 8-inch diameter billet, a CNC lathe formed the inner surface of each hemisphere, roughed the exterior, machined a flange to mate the halves, bored 8 holes on the flange for locating pins to achieve registration between the two identical hemispheres, and tapped 8 holes for 10-24 screws.
GibbsCAM visualization module Cut Part Rendering, showing toolpaths. The machined pattern cut on hemispheres appears continuous on assembled sphere.
Each part was bolted to a mandril with the threaded holes, and fixtured for surface machining. Because the weight requirement was so restrictive, the wall thickness had to be reduced to .040″. Finally, the triple pattern was cut into the surfaces such that the design appeared to be machined as a one-piece sphere, continuous and perfectly matched when the hemispheres were mated. For a good finish, they used a 1/4″ poly-crystalline diamond ball end mill and polished the surface to a mirror finish.
Blue Chip made the hemispheres, and sculptor Tom Shannon mounted rare-earth magnets inside, assembling them into spheres, which he floated on magnetic bases of his making to create the sculptures. An .018 diameter, metal cable “tether” centered each sphere above its base to prevent its wandering away from the magnetic field and falling if bumped.
GibbsCAM screen shows the toolpath being cut by the ball end mill, using the Two-curve Flow Option, where the first “curve” is a point and the second, a circle.
The sculpture was first awarded in 2005, the first of 3 recipients being Bono, the Irish rock star, for his continuing humanitarian work in Africa. Blue Chip also machined the TED awards again for 2006 and 2007. This year the award was given to President Bill Clinton, war photographer James Natwey, and scientist E.O. Wilson.
In having the first sculpture machined by Blue Chip, Shannon learned that he could cut time off his design stage, and has since directed additional work to the shop. He usually sends a sketch, from which Blue Chip develops a CAD model in SolidWorks, returning screen images for review. Then they proceed with any desired design and NC programming iterations, sending GibbsCAM Cut Part Rendering images to Shannon before machining.
The area between the circular pattern was machined using a point and a triangular sector as boundary.
Denny says that Blue Chip owes its survival to GibbsCAM and other leading edge technology. “If we hadn’t invested in something like GibbsCAM, we would be out of business. GibbsCAM, SolidWorks, 5-axis machines, and our Zeiss solids-programmable CMM will keep us competitive and growing.”
“But we also need to keep employees trained and up to date on the technology,” he adds. “My daughter Paula, for example, is the primary programmer of the Zeiss CMM, uses SolidWorks, and recently completed basic training in GibbsCAM.”
The sculpture completely assembled, with the rippled sphere magnetically levitated above its base, kept from being knocked away from the base’s magnetic field by a .018” cable tether, displayed as presented to rock star Bono, president Bill Clinton, and other TED Award recipients.
The shop will be machining Shannon’s sculpture for the 2008 thru 2010 TED awards. In the interim, they’ll be working on other Shannon projects and doing difficult machining for other industries. Long past the threat of failure, their wish list includes a return to profit sharing for employees, another Mori-Seiki with 4th and 5th rotary axis, and another seat of GibbsCAM. Apparently, the backrubs can wait.
High Tech had not moved beyond the 2.5-axis Basic Milling GibbsCAM software, so the part’s radiused cut on a taper required custom tooling. However, none of the setups were sufficiently rigid because the parts were supported with dovetails. “It was a complete nightmare,” Johnson says. “After all that trouble, we purchased the GibbsCAM SolidSurfacer and Advanced Mill modules, which gave us many more options for tackling that part.”
They had tried making the part with 2.5 axis, in four operations. Advanced Mill and SolidSurfacer allowed using a fixture on a vertical mill, and doing it in four-axis and two operations, but this lacked rigidity, so they returned to 2.5 axis with a different setup.
seleziona la lingua