IN THE LOOP: CUT TO THE CHASE

In the midst of a slowing economy, innovative steel service centers and job shops are chasing business in new markets. To retain their competitive edge, many are turning to advanced sheet metal cutting capabilities that will compliment and drive their lean manufacturing processes and ultimately enable them to reduce their costs of goods sold, revamp their price points and revisit their sales margins.

For example, Willbanks Metals Inc. (Fort Worth, TX) purchased a high-technology Fabricator XRP profile cutting system manufactured by Farley Laserlab Cutting Systems (Rockford, IL) to lower their part costs in ways that could not be achieved by conventional punch/cutting machines. This system, which drills and plasma cuts parts in one set up, is designed for structural steel shops, OEMs and steel service centers.

"We purchased this system to process parts for a new market we are entering. The flexibility of getting several processes done on one table at one time is ideal for us," says Eric Letz, vice president of Willbanks. "Our goal was to cut down material handling. This machine eliminates the majority of material handling, layout and manual processes." New jobs can be set up while existing jobs are being processed.

The system is driven by a PDF-TS CNC special purpose controller that uses a flash memory drive which is more resistant to harsh industrial environments than a hard disk drive. The controller user interface is an easy-to-use touch screen and tactile, with simple screen menus and intuitive prompting that machine operators can learn quickly. The precision of the control assures greater accuracy and better fit-up of parts, with virtually no restrictions on the size, shape or thickness of the raw material.

This system drills hole sizes ranging from 1/8 in to 2-5/8 in, depending on drill type. "We chose the XRP over similar equipment because of its drilling technology," adds Letz. "We also do a lot of contour beveling, and this machine gives us that flexibility." In addition to drilling, the system utilizes HyPerformance plasma, oxy/fuel, plate marking and bevel cutting equipment from Hypertherm, Inc. (Hanover, NH).

The plasma system control automatically transfers all plasma process control parameters when changing material thickness and material type being processed.

Another example is in the electrical components market, where Reuel Inc. (Goldsboro, NC) installed a Mid-Rail Gantry 60,000 psi (4,100 bar) waterjet cutting system from Jet Edge, Inc. (St. Michael, MN). Reuel manufactures molded switchgear components, apparatus bushings and specialty products for medium voltage electrical distribution equipment, along with traction-power substations for mass transit authorities and large-scale contractors.

Reuel added waterjet cutting to its extensive machining capabilities because it is the most effective way to cut GP03 fiberglass, one of the primary materials used in the company's switchgear components for its traction-power substation line. "Waterjet is the best way to cut parts from this material because it eliminates an aggravating fine dust that is created by other cutting methods," explains Jason Stevens, a Reuel project engineer. "This dust can cause accelerated machine wear, especially in machine ways and optical encoders."

With its new system, Reuel can now cut complex parts from virtually any material in an 8 ft x 3 ft work envelope with an exposed tank that accommodates overhead loading. Stevens already has plans to cut steel, stainless steel, polycarbonate and copper. Prior to purchasing the new system, Reuel had outsourced its waterjet jobs. "Now that we have the process in-house, we can control our process, lead time and cost savings," says Stevens.

This system uses a high accuracy ball screw drive and direct-couple AC brushless digital servo motors. Heavy metal covers with flexible lip seals protect the critical bearing components. Sturdy heavy-wall tubular steel construction eliminates vibration and increases longevity. The industrial PC controller can be configured so that all three axes are fully programmable (Z optional).

A 50 hp iP60-50 intensifier pump produces output pressures from 1,000 to 55,000 psi (3,800 bar) with flow rates of 0 to 1.1 gal (5 l) per minute to various cutting, surface-preparation or cleaning tools. It uses a non-threaded high-pressure cylinder with an improved performance check valve and low torque requirements.

Fabricators trying to penetrate niche construction markets should consider the Global Rotator Infinity plasma bevel unit found on the TMC4500ST gantry cutting system from MG Systems & Welding, Inc. (Menomonee Falls, WI). This infinitely continuous rotation contour plasma bevel unit is capable of accurately cutting bevel profiles (non-vertical) on nearly any contour for weld-preparation surfaces or for active cutting edges as used on excavator buckets, backhoe buckets or other earth engagement tools.

Using a multi-axis CNC control, the torch bevel angle may be changed during linear or circular programmed motion to yield a smooth transition from a positive angle to 0 deg, continuing on to a negative angle (as required for weld groove preparation). When the machine is programmed to cut at a bevel angle, the current, voltage and stand-off height are all controlled by the same NC part program.

The bevel angle is automatically set using a combination of A-axis and C-axis interpolation by the CNC. The C-axis may be programmed as a positioning axis or a coordinated motion in conjunction with the X/Y linear axis. When operated along with X/Y motion, the C-axis will maintain the bevel position tangent to the direction of travel. Bevels and land cuts can be created via multiple passes.

The unit rotates infinitely on the C-axis at 50 rpm to reduce cut cycle and programming time. Response time from 0 to 45 deg is less than two seconds. A lateral and vertical torch "decoupler" collision detection device prevents torch damage in the event of a collision. Automatic analog arc voltage controls the torch height with an accuracy of ±.006 in during bevel angle cutting of +45 deg through -45 deg, with corner loops less than 0.394 in without requiring torch start/stop commands.

Suppliers trying to enter the truck/trailer market should look closely at the MAXIMO 2D Laser System from PRIMA North America, Inc. (Chicopee, MA). This very large laser system handles oversize sheet metal lengths with a customer-specified bed up to 10 ft x 157 ft. "This is one of the largest systems of its kind in North America," remarks Thomas Burdel, vice president of sales and marketing for PRIMA Laser.

The system is configured so that the integrated mechanical structure, laser generator, CNC, moving carriages, optical chain and focusing head travel on rails over a fixed working table to process sheets. A flying optics beam delivery system allows the work piece to remain stationary during the cutting process.

High wattage CO2 laser resonators are available in 3-axis and 5-axis versions with 10 ft X-axis longitudinal movement, 157 ft Y1-axis transversal movement, 6 in Z-axis vertical movement and a further Y2-axis that transverses beyond the Y1 stroke, as far as the sheet metal being processed requires.

The advanced control includes a focal axis for automatic and programmable adjustment of the focal position and stand-off height. This allows the cutting of a variety of materials and thicknesses without manual intervention and keeps the process accurate in the entire work area. The head comes equipped with an anti-collision safety device and a rapid lens changing system from 5 in to 7.5 in. The system uses a fast-piercing unit for thicker ferrous material and a laser piercing monitor to optimize thick material processing. Off-line 2D CAD/CAM and nesting software is available.

Despite its size, this system does not require a complete foundation. Thanks to a peculiar patented solution for the main carriage guidance and isostatic support, only two plinths of the same length of the Y2-axis stroke are needed.

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Mike Riley is the editor of Fabricating & Metalworking magazine and the author of Backfield in Motion (Derek Press, 2007). Contact him at 205-681-3393 or [email protected].

Farley Laserlab Cutting Systems (HG-Farley Laserlab USA Inc.), North American Division, 4635 Colt Road, Rockford, IL, 61109, 815-874-1400, Fax: 815-874-1700, www.farleylaserlab.com.

Hypertherm, Inc., Etna Road, PO Box 5010 Hanover, NH 03755, 603-643-3441, Fax: 603-643-5352, www.hypertherm.com.

Jet Edge, Inc., 12070 43rd Street NE, St. Michael, MN 55376-8427, 800-538-3343, www.jetedge.com.

MG Systems and Welding, Inc., N141 W9427 Fountain Boulevard, Menomonee Falls, WI 53051, 262-255-5520, Fax: 262-255-5170, www.mg-systems-welding.com.

PRIMA North America, Inc., 711 East Main Street, Chicopee, MA 01020, 413-598-5200, Fax: 413-598-5201, www.prima-na.com.

Willbanks Metals, Inc., 1155 N.E. 28th Street, Ft. Worth, TX 76106, Phone: (817) 625 – 6161, www.willbanksmetal.com.

Reuel, Inc., 200 West Dewey St., Goldsboro, NC 27530, Phone: 919-734-0460 www.reuelnc.com.