Federal Products Formscan Optional Piston Software Benefits Interfaces with Formscan 3300 or 3600 circular geometry gages Ovality parameter with changeable angular offset Radial accuracy to ±1 min. Continuous 360-degree measurement www.fedgage.com

Piston Maker Fires Up Specialized Geometry Software

Great drivers don't move from the interstate to the NASCAR/Winston Cup circuit with skill and determination alone; auto-racing success also has a great deal to do with what's under the hood.

 Federal Products Co., maker of precision dimensional gaging solutions, does its part to improve manufacturing accuracy and quality control for high-performance engines with its Formscan circular geometry gage with optional piston software. This software package, designed specifically to measure the unusual geometry of pistons, efficiently analyzes such features as piston ovality and skirt profile.

 JE Pistons Inc. of Huntington Beach, California, has embraced the Formscan software packages. JE Pistons develops and manufactures automotive racing pistons (many of which can be found in many top NASCAR circuit cars) and marine racing pistons, but has found conventional tools to be less than ideal for measuring these parts. Whereas other parts are generally nominally round and straight-sided, pistons for reciprocating engines are deliberately engineered out-of-round and barrel-shaped. Unfortunately, most software reports these essential geometric contours as deviations. JE Pistons clearly needed software that would allow it to define ovals and barrel shapes as nominal specifications and measure parts for conformance to these specifications.

 JE Pistons found what it required in the optional piston software, which is available as an add-on to Federal Products' Formscan metrology software package. The piston manufacturer uses the standard package to measure such parameters as ring groove flatness, but the added software takes over for measurements specific to piston manufacturing. It allows users to specify and measure an oval piston's change in radius, or "cam drop," at a selected angular increment. The longest radius is usually 90 degrees from the wrist pin bore centerline, but the piston software lets users select a different angular offset for the high point and specify tolerances for asymmetrical pistons whose front and rear profiles differ. Whereas a coordinate measuring machine takes discrete measurements, often generating results that conflict with the measurements of piston customers, this specialized software offers continuous measurement, taking 4,096 data points in one 10-second, 360-degree revolution.

 The optional piston software can operate on a 3300 or 3600 model Formscan circular geometry gage. Both models offer user-friendly touch screens, eliminating the need for operators with extensive geometry knowledge. JE Pistons uses the more affordable benchtop-configured Formscan 3600 system and piston software to develop new cam and skirt-profile designs, creating them in computer-aided design (CAD) and downloading the data directly to computer numeric controlled (CNC) lathe controllers. The lathes are specially designed to turn pistons, but according to Eric Nessa, vice president at JE Pistons, "the ability to cut an oval cross section on a lathe has an element of uncertainty." To ensure that the cut parts conform to the design, operators measure the parts on the Formscan gage and use the piston software to analyze them. The process is often repeated and used to fine-tune the CAD file or the CNC programming to attain the desired piston shape.

 JE Pistons also applies Formscan equipment as a quality inspection tool, especially on its highest-end product line. Not only can the piston manufacturer use the software to check cam drop and skirt profile, but also to monitor timing, which Nessa claims is "absolutely critical." The Formscan gage and software is a practical means to inspect the top and bottom faces of ring grooves for flatness and parallelism on a production basis. The software can also confirm the geometry of forgings that manufacturers receive from suppliers.

 In addition to their new prominence at JE Pistons, Federal Products' Formscan metrology software packages and gage systems are employed by other major automotive and off-road engine manufacturers, bearing manufacturers, and fuel-injector manufacturers. End-users have found a place for Federal Products' gages and software, as well: One top NASCAR/Winston Cup racing team uses a Formscan gage to double-check the geometry of the pistons it receives from its supplier and to experiment with its own geometry developments.