Delcam's PowerINSPECT software chosen for nuclear casting inspection
Inspection with PowerINSPECT is helping machining and pattern-making shop, J.P. Pattern, with its contribution towards building machines that the contractor, the Auburn University Engineering Department Fusion Laboratory, hope will eventually solve the world’s energy problems with nuclear fusion. Cast and machined components from the company will fit over the ends of the toroidal pressure vessel at the heart of the device.
"We are machining a set of 10 identical aluminium castings whose main function is to guide the windings of the wire that makes up the helical coils, which generate the magnetic field,” said J.P. Pattern President John Puhl. His main concern is making sure the ten castings are exactly to specification so that each set of five will fit together exactly as designed.
"The biggest dimensional challenge is dealing with warpage in the castings due to the forces of machining,” said Gerald "Gary” Puhl, John’s brother and vice president of this family-owned and operated firm in the Milwaukee suburb of Butler, Wisconsin. "Even though the dimensional constraints were not all that tight, these pieces warp from cooling and during rough machining. We also measured the rough castings to make sure that enough stock was there so we could machine to final dimensions. That meant each casting was measured at least twice. Each set of five castings measures nearly 9 feet in diameter and stands about 18 inches high.”ng as measured at least twice. Each set of five castings measures nearly 9 feet in diameter and stands about 18 inches high.”
The dimensional data in these critical measurements was handled by a Romer Cimcore portable CMM fitted with PowerINSPECT . "There were 17 features on each casting to be documented and the winding channel was the toughest and most complex of them,” Gary Puhl said. "The channel is a very complex geometry. It is a U-shaped cross-section that is a partial helix that is bent around a torus or doughnut shape. The distance between the wall surfaces of the U-channel was designed to be a constant value if the helix were unravelled.”
"The software really was a big help to us when we had to verify the dimensions between the walls in the helical trough in each casting,” said Gary Puhl. "Without the 3D CAD file and PowerINSPECT, I don’t know any other way we could have verified those dimensions.”