CaptiveAire Automates Stud Welding Process with Custom Gantry System

In 1976, entrepreneur Robert L. Luddy founded Atlantic Fire Systems in Raleigh, NC, selling automatic dry chemical fire systems. It soon formed a relationship with the co-founders of Golden Corral restaurant chain and expanded by opening a sheet metal shop. This venture led to the formation of CaptiveAire, now a leading manufacturer of commercial kitchen ventilation systems.

CaptiveAire’s ventilation packages include hoods, exhaust fans, and fire suppression systems. With 100 sales offices across the U.S. and Canada and six manufacturing plants, the company employs over 1,300 people.

To improve the labor-intensive stud welding process in its manufacturing, CaptiveAire enlisted the help of Spectrum Design LLC to develop a custom, gantry-based CNC system. This system would automatically position and weld metal studs, ensuring precise alignment and minimizing manual labor.

Stud welding is an ideal method for the food industry, as it eliminates contamination sources and prevents leakage. CaptiveAire has been using capacitor discharge stud welding to produce stainless steel oven hoods. The studs are surface-mounted, creating strong, seamless welds with no reverse side markings.

The previous manual welding process posed challenges, such as difficulties in positioning the studs accurately against the 18-gauge parent material. Spectrum Design’s automated system, with International Welding Technologies Inc. (IWT) as a partner, solves these problems. IWT provided the necessary CNC machines with multiple I/O capabilities to drive the capacitor discharge power supplies.

Isel USA Inc., in collaboration with IWT, developed a Cartesian robot equipped with a breakout board for the gantry system. This robot ensures precise positioning of the studs before welding, reducing the need for manual intervention. Isel’s gantry systems offer two to six axes of motion and are suitable for various applications, including welding, milling, and inspection.

The gantry system used by CaptiveAire boasts high accuracy and repeatability, providing an accuracy of ±100 microns per 300 millimeters and a repeatability of ±100 microns. It achieves a speed of 152 millimeters per second, enabling efficient production rates.

With the implementation of this automated system, CaptiveAire improves efficiency, reduces labor requirements, and ensures consistently high-quality stud welds for its commercial kitchen ventilation systems.