Smaller batches, faster turnaround, a wider mix of products and more complex applications are the reality for manufacturers of all sizes. In a marketplace that is fiercely competitive, getting the balance of quality, cost and throughput is a common challenge.
Technology like the punch-laser combination machine, therefore, helps improve a shop’s flexibility and overall efficiency. Using a combination machine, manufacturers can cost-effectively handle short run quantities, quickly turn around a range of jobs, and reduce secondary operations and material handling.
The “one machine, one footprint” concept is attractive to those who don’t want to make the investment in two separate machines. Beyond the saved investment dollars, users benefit from putting work on a single machine that can punch, form and cut.
Combo rewind
At IMTS 1978, Strippit introduced punch-laser combination technology to the sheet metalworking industry with the debut of the Lasertool. The Lasertool joined a 30-ton Strippit Fabri-Center NC turret punch press and a state-of-the-art Photon 500-W CO2 laser. The patented design was promoted as delivering the utmost in flexibility, a combination that would reduce setup time and secondary operations, process metals and non-metals, cut intricate shapes without the need for special tooling and slash material handling time in half.
The laser added a “soft tool” to the numerically controlled punch press, which was the leading sheet metalworking technology of the day, expanding the capacity of the Fabri-Center 1250/30/1500 20-station turret machine without the need to invest in additional hard tooling. With the Lasertool, a fabricator could process a wider range of material thicknesses using less tonnage and cut more complicated geometries without special tooling. This opened up an entirely new world of application possibilities and made it possible to process short runs and prototypes more quickly and efficiently.
While the punch-laser combination machine seemed an ideal all-in-one solution, the cost of ownership (higher because of the two technologies) and the learning curve (considered significant) kept the sales of this machine tool limited mostly to a small group of fabricators willing to embrace the innovation simply because it was new, cutting-edge technology.
Four decades later, the punch-laser combination machine is a more practical solution for today’s manufacturers. Combination machines accounted for almost 30 percent of all punch press sales in 2019 and sales for this technology are trending up.
Today, a broader range of fabricators are giving this technology another look thanks to two key drivers: with high-mix, low volume the norm, fast turnaround and flexibility are more critical than ever, and advances in technology – namely the emergence of fiber laser and enhanced forming capabilities on the punch press – have broadened the scope of what’s possible with a punch-laser combination machine.
Purpose-built
The Lasertool was born from a punch press with a laser source added to it. In the late 1970s, laser cutting was just beginning to be used to process metals so the technology was more of an enhancement or secondary feature of the Lasertool. Punch-laser combination machines that use a stationary (added-on) cutting head compromise the full capability of laser technology because of restrictions caused by the dynamics of the positioning system.
The modern combination machine, like LVD Strippit’s next-generation Strippit PL, is designed as a punch, laser, form and bend center. Because of this, it delivers the advantages of punching and laser cutting technologies in an optimal way. The table of the Strippit PL is designed so that the machine is able to process a 5-ft.-by-10-ft. workpiece without repositioning for both punching and laser cutting. This saves on production time, material usage and material handling as it takes a job from start to finish. Material utilization is increased by using the laser to separate parts from a nest.
The Strippit PX-1530-L model featuring a single-head punch press and 3-kW fiber laser is able to punch holes in material up to 1/4 in. thick, produce bends up to 3.5 in. wide and laser cut materials up to 0.390 in. thick. Forms can be made up to 3 in. high and every tool is indexable.
Fiber advances
The advancement of solid-state fiber laser technology has changed the story for the combination machine. The metalworking industry is dominated by the fiber laser, which has proven to be a stable tool. New higher power fiber lasers make it even faster and easier to process thin to thick materials, as well as a broader range of materials, including aluminum, copper and brass. Early CO2 lasers used on combination machines were in the 500-W to 1,700-W range and, therefore, limited in their cutting capabilities. Modern combination machines typically use 3-kW or 4-kW fiber laser sources.
The speed and efficiency of the fiber laser and the fact that a fiber laser requires significantly less maintenance than a CO2 laser source makes it a highly productive tool. Because the fiber laser is so efficient and economical to use, the operating cost of the punch-laser combination machine is less, and the cost of investment in a combination machine is also reduced. As more fabricators become comfortable with fiber laser, its use in combination technology has greater appeal.
The modern punch press also has more forming, etching and marking capacity than ever before. A range of forms such as louvers, tabs, coining, embosses, knockouts and flanges can be produced on the punch press. Forming on the machine adds value because it reduces or eliminates secondary operations. The combination machine can now produce high forms on complex geometries.
The fiber laser delivers a high edge quality and the punch press’ forming capability means the entire operation can be handled on one machine. This is especially attractive to manufacturers who need to reduce labor costs or who don’t have the time, personnel or floor space to transfer jobs back and forth to different machines.
In addition to forming, tapping can also be handled by the punch press and is another secondary operation that can be eliminated using a combination machine.
Control and software technology have also changed the landscape for the combination machine. The Lasertool allowed the user to laser cut virtually any geometry that the operator was able to program. The problem was that programming the job and setting the application parameters, including speeds, feeds, power levels, assist gas pressure and types of assist gas, was no easy task. This information was input and plotted manually and required knowledge of trigonometry and some geometry. Today, macros built into the machine and user-friendly CAM software make programming and job setup virtually automatic.
Furthermore, when the Lasertool was launched in the 1970s, automation was not part of the conversation. In 2020, automation is often a discussion point. Most combination machines offer the same automation options as a standalone punch press or laser. The Strippit PL is equipped with a 16-in.-by-60-in. programmable part chute for the offloading of laser cut parts. It offers an optional compact tower for loading, unloading and storage of raw materials, skeletons and finished parts as well as an optional flexible automation system for loading, unloading, part picking and stacking.
Overall, the punch-laser combination machine has changed significantly from the Lasertool that debuted in 1978, but the motivation behind using combination technology remains unchanged. The need to have more flexibility in producing a high mix of jobs in small lot sizes or full production runs, to minimize material handling time, to produce high-quality parts faster in a shorter time frame, and to improve process flow are reasons why combination technology is experiencing a resurgence.
A large job shop with a constantly changing workflow is an ideal candidate for the technology, but so too are fabricators looking to keep ahead of what their customers demand.
