API Services, the metrology services arm of API Metrology, used a portable CMM scanning arm to inspect 1,500 diesel engine castings for Tupy after a mold shift threatened to send the entire production run to scrap. Working with Tupy and its customer Cummins, API Services validated more than 80 percent of the blocks as usable, avoiding what the companies described as costly rework and downtime.
The castings came from a machine shop Tupy acquired in Mexico to supply pre-machined blocks for Cummins diesel engines. During the pour, the lower casting mold shifted, leaving some blocks short on material and others with excess in undesirable spots. Tupy's shop made adjustments before shipping the blocks, but Cummins wanted to scrap the entire run rather than risk installing out-of-tolerance parts.
Tupy first sent quality controller Matt Bommarito to Cummins' Indiana facility to measure the blocks by hand, but manual gauging couldn't keep pace with 1,500 units or catch every discrepancy. What's new here is the shift from manual gauging to an automated scanning workflow that measures a full engine block in six to seven minutes. Engineers who manage supplier disputes over casting tolerances will recognize the value of a third-party inspection both sides can trust.
API Services built a 40-feature inspection routine covering crank bearings, piston bores, water jackets, oil rifles, and other casting areas, tracking four separate machining phases from raw casting to Cummins-finished block. Tolerances on individual features ranged from plus or minus 0.150mm to plus or minus 1.5mm depending on criticality. The team paired the arm with reverse-engineering software to automate measurement and reporting, and set up an assembly-line style loading and unloading process to cut inspection downtime further.
With inspection reports in hand, Tupy and Cummins settled the dispute over which blocks met tolerance, sparing the bulk of the 1,500-unit run from scrap. API Services runs similar arm-based inspection work across its lineup of Radian laser trackers, scanners, and machine tool calibration systems, typically called in when a supplier and customer disagree on whether a manufacturing error actually compromised a part.
