At the hub of OEM's success is strategy relying on CNCs.

At the OEM Trailer Business Unit of Webb Wheel Products Inc., a new 100,000-square-foot facility in Tell City, IN, brake drums and hubs are manufactured for heavy-duty trailers. The production strategy is heavy duty as well.

Founded in 1946, the company is a major supplier to OEM trailer manufacturers, serving customers nationwide. At the heart of the Tell City plant are 16 Maus machining centers, used for turning, drilling, grinding, and marking ductile iron and gray iron into the brake drums and hubs. Maus is an Italian machine builder, represented in the United States by the Reich-Companies of Trussville, AL.

In designing the plant, says Webb Wheel's David Link, vice president of manufacturing, great emphasis was placed on the total control of the overall metal-machining process. Webb Wheel utilizes a novel material-handling system--one that is linked to the machining center control panels for integrated part movement.

Webb Wheel's products include cast brake drums in more than 400 styles, ranging in sizes from 12.25" x 6.00" to 18.00" x 8.00"; transit drums, both vented and ribbed design; BTS (Brake Turbine System) drums up to 16.50" x 8.62" for use with Lynnfin brake turbines; trailer, drive and steering axle hubs; standard and ABS rotors; and spoke wheels of many types. The Tell City plant, opened at the end 2004 and headed by president Kent Finkbiner, manufactures hubs and drums to suit the high-volume requirements of Webb's OEM business. The facility is organizing to achieve ISO 9001:2000 certification.

The Maus machining cells are all controlled by Siemens SINUMERIK 840D CNCs, each of which is used to monitor axis movement, spindle movement, rotary table positions, transfer lines, ancillary robotics, CMM probing, and laser detection orientations.

Control is everything

The 840D is a sophisticated CNC system that offers a wide range of specialized functions for milling, drilling, turning, grinding, and material-handling technologies. Its control capabilities also include nibbling, punching and laser-machining processes. The SINUMERIK 840D offers users innovative features that increase productivity on the manufacturing floor, especially the challenging segments of high-speed and five-axis machining. These features include the ability to assign various axes and spindles to one CNC in sequence and link to multiple inline operator panels. In addition, a Windows XP or Windows NT operating system can be utilized. The CNC can run ancillary robotics, transfer lines, even unattended, lights-out mode laser detection devices.

At Webb Wheel, each machining cell can be programmed with the entire work cycle for the particular hub or brake drum being produced. When a changeover is required, the process has distinct advantages in time and movement efficiencies, says Sandra Selwan, marketing manager for Maus.

"When we change production on the cell, we simply create screens for the operator," she explains. "On these screens, the operator can answer yes or no in most cases. The standard program on the Siemens CNC interprets the answers and predisposes the cell for the new part."

In terms of logistics, Webb Wheel's Link makes special mention of the remote controller, which is used with the CNC. "The Siemens HT6 handheld device allows the operator to interact with the host control panel from various locations on the cell," he notes. "This is extremely helpful."

Thumbs up from Maus

Webb Wheel utilizes both the Maus MTV high-volume machining cells and the Maus MTC vertical turning centers with 36-position tool changers for its hub and brake drum production. According to Webb Wheel sources, this gives the Tell City plant great flexibility while reducing its response times for special orders.

"The large, user-friendly control panels are a real plus for our operators," Link says. "The SINUMERIK 840D gives us great versatility for advanced programming right at the control and the large memory capacity is ideal for managing the multifunction work cells especially. We utilize a gantry system to move product from one operation to the next in our work cell. The Siemens CNCs are controlling and calculating the functions of both the work cells and the material handling system."

Link also notes the end-user support Webb Wheel received onsite from Siemens. "It has proven very instrumental in the development of our Tell City work force," he says.

Webb Wheel uses other controls on the machining cells and work centers in its other facilities, but chose Siemens after a thorough review done in partnership with Maus. Maus vertical lathes are built as single-station, dedicated-operation machines, intermediate work cells and turnkey production lines. The builder currently utilizes Siemens controls on all machines built. Maus was founded in 1986 and also supplies fettling machines to the foundry industry, as well as special-purpose equipment of many types. Siemens Machine Tool Business, www.rsleads.com/511tp-150