By Clare GoldsBerry, associate editor

Water jet cutting has its place, and is the right choice for multi-layered applications.

Plasma arc (on the left) and gas tungsten arc (TIG) cutting torches are options to make the right cut in the right way.

Demand has increased for laser cutting because the technology provides highspeed cutting with a high-degree of accuracy and good control over the amount of heat that is conveyed to the metal being cut. The good heat control allows metals to maintain the characteristics for which they were designed and produced.

With a laser beam that typically has a 0.2 mm diameter at the cutting surface and power of 1000 watts to 2000 watts, laser also can cut complex exterior contours on metals.

One of the largest producers of fabricating machinery including state-of-the-art laser cutting machinery, Trumpf Inc. (www.trumpf.com) has introduced several cutting-edge changes to its line of flat sheet laser cutting machines with integrated automation. Two of the most notable changes are the company's new, compact enclosure that is 75 percent smaller than a conventional enclosure and its options for working ranges.

"Compact features always have been an advantage of this machine," James Rogowski, product manager for laser cutting machines and automation at Trumpf, said. "This new cover is just one-fourth its original size, which offers advantages for fabricators."

Rogowski said the key benefits of the new design include faster installation, easier accessibility, and facilitated material exchange. Additionally, the machine now is made with an easy-to-use freestanding control that is similar to the control on the company's punch machines.

The new working range options that are available for the machine include 5-foot-by-10-foot and 4-foot-by-8-foot alternatives to its original 4-foot-by-10-foot standard range..

Trumpf continues to expand its line of laser cutting machines with integrated automation to meet a wider variety of customer requirements for the global economy, Rogowski said.

Paul Grimes, president of Anderson Tool & Die (www.atdmachineshop.com) said his company recently purchased a Trumpf laser cutting system, and has used it to increase its production capabilities and to reduce its cutting time.

Amada America (www.amada.com), a producer of a wide number of products used in the fabrication industries, introduced a laser cutting system that combines the advantages of high speed and flexibility with a laser that can be powered to 4000 watts for high-speed cutting. The company says its EML K3610NT has the advantages of servo-electric punch press for high speed production of short run sheet metal parts and a laser cutter. The company said the machine can be considered a turret punch press with minimum setup or a laser with high-speed cutting and forming capabilities.

Meanwhile, GE Fanuc (www.gefanuc.com) has upgraded its Cincinnati CL-6 precision laser cutting system to increase its performance. The upgrade includes the GE Fanuc C200E "Level UP" resonator. A GE "Ecomagination" development, the resonator puts out 2500 watts of power for high cutting speeds at the same price as the company's previous, 2000-watt model. However, GE Fanuc points out that the C200E resonator uses the same electrical input and chiller load as the previous model, and allows the Cincinnati CL-6 to cut thicker materials faster without an increase in operating costs, and improved accuracy for high-quality parts in short or long runs. the company said the Cincinnati CL-6 requires few hours for installation.

The machine is designed to cut a variety of metals, and its standard, non-contact heads maintain exact standoff from conductive materials. The company said that enables a user to cut sheets precisely, even if they are not perfectly flat. The machine is equipped with a Windows NT control and Ethernet that permits direct downloading of part programs. GE Fanuc said CAM programming and nesting software from Cincinnati converts 2D CAD files into machine code that uses the entire range of capabilities inherent in the machine, while optimizing productivity and part quality.

Waterjet Cutting systems
Waterjet cutting systems are versatile and can cut almost any shape in a single step, and they provide edge quality that typically does not require secondary finishing. Those characteristics make waterjet cutting an attractive for speed and cost reductions. Additionally, costly tool changes are not required to change to different materials from job-to-job.

Abrasive waterjets cut with erosion, rather than shearing or heat, so they produce exceptional edge quality and do not induce heat-affected zones or mechanical stresses into the cut metal or other materials.

However, there are some challenges to waterjet cutting. Errors can be caused in the geometry of the cut -part geometry by the bending of the stream.

Flow International Corp. (www.flowcorp.com) says the faster that a waterjet cuts a material, the more the stream exit point – at the bottom of the cut – lags behind the entrance point at the top of the cut. Also, as the cut speed increases, the "V" shaped taper become greater.

To solve this problem, instead of slowing down the cut speed, engineers at Flow International designed and developed a cutting system that tilts the cutting head. The company said its Dynamic Waterjet produces parts with improved accuracy at higher cutting speeds.

The Dynamic Waterjet's cutting head is not fixed at a 90-degree angle to the plane of a flat plate. The cutting head is programmed to tilt at correct angles that depend on the material being cut and on the part.

That tilting action is powered by software that controls the wrist. Flow International said its the Dynamic Waterjet can cut parts as much as four times faster than traditional waterjet cutting machines, while also eliminating taper.

Plasma Cutting
Plasma Arc cutting uses open arc that is constricted by a small nozzle, or orifice, that combines with the electrode to forms the plasma to the correct shape to cut the workpiece. The gas used in plasma arc systems typically is air. The gas is combined with an electrical current to create a high temperature plasma arc. When put into contact with an electrically conducive material, the arc passes through the metal, melting a thin area, and the force of the arc pushes the molten metal through the workpiece to sever the material.

The plasma process can cut any type of electrically conductive metal including brass, copper and titanium and it can cut galvanized metals. Also, it is a fast process, and can cut as much as75 in. of metal per minute on 3/8-in. steel. Plasma arch cutting also is clean, and produces a small and more precise kerf with well-defined, and straight edges.

Late last year, Miller Electric Manufacturing Co. (www.millerwelds.com) introduced a lightweight plasma cutting, the Spectrum 375 XTreme that has multi-voltage plug technology.

The cutter weighs 18 lbs., and the company said it is well suited for HVAC and other industrial applications, and light auto customization work. Information and specifications about this and other plasma cutters can be found in Miller's Plasma Cutting Guide, an eight-page guide that includes basic instructions on plasma cutting, information about equipment operation and plasma safety guidelines. A copy of the guide can be downloaded from the company's web site or ordered through the company's toll free phone number (1-800-4-A-MILLER)

Hobart Welding Products (www.HobartWelders.com) introduced a plasma cutter, the AirForce 250ci, that features a built-in air compressor and lightweight inverter technology. This unit offers powerful cutting abilities and weighs 27 lbs., half the weight of the previous model. This plasma cutter is powered by standard 115-volt, alternating current (AC)household current.

The AirForce 250ci is designed to cut 1/8-in. mild steel and to server 1/4-in. steel. It allows cutting with an arc that can be as long as 3/16 in. That arc is as much as three times longer than the arcs on other plasma cutters, and Hobart said that it helps to improve results when cutting freehand. The AirForce 250 ci is designed for light-duty work, and replaced the company's 250 A plasma cutter, and is the only model that the company sells that has a built-in air compressor.

Caleb Krisher, manager for Hobart's plasma cutting products, pointed out the machine's multivoltage capability that offers the convenience of running from a 115 volts outlet in a home setting or a 240 volt outlet in an industrial setting. The higher voltage doubles the machine's cutting performance, Krisher said.

Portability means a lot to users of the smaller, more lightweight plasma cutter, Krisher said. "We took what had been a transformer product that weighed more than 50 lbs. and took that down to 27 lbs., replacing the transformer with inverter technology," Krisher said. The weight reduction also improved portability for the unit.. And, some users appreciate the built-in compressor feature that allows the AirForce 250ci to be used in settings in which a compressor isn't available. Also, its versatility allows it to be used by the home hobbyist who needs a plasma cutter in car restoration, and for light industrial applications.

Welding equipment manufacturers have competed to develop a plasma cutter priced below $1,000, and Hobart's AirForce 250 ci is the first, with a manufacturer's suggested retail price of $839, Krisher said.