Grede-Iron Mountain gains edge with 3-D scanning.

Grede's Iron Mountain Foundry, Kingsford, Mich., works year-round producing complex hydraulic valve castings for the agriculture industry, as well as open-faced valves for transmissions in medium- and heavy- duty tracks. These complex castings have hundreds of dimensions to define the intricate geometry. Some customers no longer supply prints of their castings, but instead supply solid models that define the math data used to construct the tooling for the casting.

To check the accuracy of castings made from the tooling, a print must be made from the model to check casting features. The prints take weeks to draw and dimension, costing the metalcasting facility thousands of dollars. Grede-Iron Mountain was looking for a way to expedite the new job start-up process while reducing associated costs.

The solution was the use of a Romer Articulated Arm Coordinating Measuring Machine with Perceptron Laser Scanner and Romer Articulated Arm from Exact Metrology, Algonquin, Ill. The scanner uses software capable of creating a solid model from a casting scan and comparing it to the casting model supplied by the customer.

"We can overlay our own model of the casting with the original model and see very clearly whether we are right on target, going toward the plus side of nominal, or running shy of material," said Bill Collard, manager of metalcasting engineering at Grede-Iron Mountain. "We generate a nice picture or map that anyone can look at and see at a glance if we are in print or out of tolerance."

A conventional dimensional layout analyzes just one point of a part, but the Perceptron scanner analyzes the entire surface. This gives a more complete and dimensionally accurate view of the quality of the part produced. With this accuracy comes simplicity for the engineers examining the models to ensure the part will meet requirements.

"With the complex parts we use, some have more than 1,000 measurement points," Collard said. "No one wants to take the time to look at all that data on a layout report."

After six months of use, Grede-Iron Mountain already has seen the technology's benefits. Layouts that took days to complete now take only hours to scan with the equipment and software from Exact Metrology. Costly, time-consuming prints no longer are required. Tool wear review can capture the entire tool and provide an excellent picture of the tool's life cycle, and the facility has the ability to use it with reverse engineering of tooling.

To check tooling wear, Grede-Iron Mountain scans new and approved tooling and stores the results. Later, after the tool has been used, it can be scanned again and compared with the original file to see how much wear occurred. Stored files also are saved for making new replacement tooling when the original nears the end of its life cycle.

When a tool has had numerous adjustments and changes to "tweak" items into tolerance, it also can be scanned to generate a solid model. This model can be used to create a new tool which is dimensionally accurate from the first cut, saving time and money for adjustments often necessary on new tooling.

Grede-Iron Mountain now uses the laser scanner with almost all new jobs and finds that an increasing number of customers are looking for a scanned model rather than a conventional layout from its metalcasting facility.