Two Kuka robots are positioned on either side of a stator core.

Emerson Motor Co. (www.emersonmotors.com) needed to automate the welding system used to produce the stator cores for motors manufactured at its Mena, Ark., plant. It asked Encobotics (www.encobotics.com) to review its welding system, and to develop a more efficient automated cell.

The old welding system used hydraulics without automation to position the welding machines. After a core was brought into the cell and positioned, the welding machines dropped into place, took one "shot," then the core was repositioned for the next shot. This process was repeated until the welding was completed.

To eliminate this inefficiency, Encobotics (www.encobotics.com), a robotics integrator, developed a system that includes two Kuka KR6 Arc robots working in tandem.

In the new system, an overhead hoist brings a core to the cell, where an operator manually positions the core on the welding table. Then, as one robot reads the barcode on the documentation that follows each core through the manufacturing process, the other robot measures the diameter and height of the part to determine if it matches the barcode information and is the correct part.

Once the part is verified, the stator core is matched with the correct welding procedure in the company's main computer network, and the robots proceed with their tasks.

Each robot is equipped with a plasma torch and a gas metal arc welding (GMAW) torch. The plasma torch cuts a groove on each side of the core, then theGMAW completes the procedure on the core.

Emerson estimates that the new system doubles production by completing stator cores in about half the time it took with the old process.

Further, Emerson gained another advantage by using PC-based Kuka robots: Encobotics engineers were able to write a program that includes all 2,000 Emerson parts. If the wrong-sized stator core is on the welding table, the robots can search the database and find the correct weld parameters to match the core's dimensions, and can proceed with their tasks to reduce rejects and improve production time.