Flexibility and efficiency are making punching a popular choice for fabricators

April 2013 - Whether you tweet, text, email or talk, a recent Time magazine mobility poll reveals 84 percent of people in eight countries surveyed can’t go a single day without their mobile devices in their hands. Convenience and the promise of greater efficiency make the temptation to constantly stay connected compelling. Instead, a growing number of businesses and consumers believe the technology boom that birthed these devices is stealing time while pushing society to move faster than ever.

Manufacturers also are feeling pressure to pick up the pace in the face of shrinking time frames. Customers require shorter turnarounds, faster deliveries, tighter tolerances and higher part quality with zero or just-in-time inventory, leaving many fabricators scrambling to find more efficient capital equipment solutions. In the face of post-recession market demands to cut costs, punching is gaining in popularity because of its flexibility and the introduction of some recent technological developments. 

Trimming time

“Most of the effort in the industry has been focused on making machines go faster to reduce cycle time,” says Robin Barbero, vice president of sales and marketing for Haco-Atlantic, Franklin, Mass., “but that’s just one part of the equation. Improving features in the machine that can save time across the entire sheet significantly raises the level of efficiency and optimization fabricators can achieve—factors that directly impact a company’s bottom line.” Haco Worldwide builds advanced fabricating equipment including punching machines, press brakes, CNC plasma and laser cutting machines, shears, ironworkers, mechanical and hydraulic presses. 

“A punching machine is the most economical way to produce parts,” Barbero says, “but the advantage it has over technologies like plasma, laser and waterjet is that you can do more than just cut shapes. You also can form, tap, bend and roll, which eliminates secondary operations and helps reclaim lost production time.” 

Punching 101

Most CNC punch presses are turret-type machines with three basic assemblies: a powered press turret, a main work bed capable of 2-D movement and a set of computer-driven controls. The key difference is between a CNC punching machine that uses tools stationed inside the turret and one that changes the tool from the turret into an
indexing punch head, says Andy Raedt, senior product manager for Haco Worldwide.  

A tool change with a turret machine takes just a few seconds but also requires a complex turret station to house tools of different sizes fitted to pre-specified positions. Tools and turret holders are costly and only a few tools can be rotated with the help of a low-speed index mechanism. Forming is limited along with the ability to provide parts with a non-scratch surface. “These things can bleed precious production minutes from a fabricator’s operation and reduce the value-add of the part itself,” Raedt says. Tool movement inside the turret creates friction, leading to wear and tear. The machine also requires frequent tool station realignment and tool spring replacement—activities that add to the cost of operating the equipment.

“Fabricators want to be able to change tools with minimal downtime, but they also need equipment that allows them to adopt new tooling styles,” says Raedt. “Tooling manufacturers are inventing tools for a wider variety of applications such as manufacturing steel doors, construction of electrical cabinetry, panels, covers, brackets, prototyping, HVAC, appliance and metal furniture. We knew we needed to develop a punching solution that could address these issues.”

A different approach

Haco engineered its Q series punching machines with a round automatic tool changer that can accommodate any size tool in any station and a single punching head with a high-speed auto index system. The machines are offered with an 18-, 22- or 30-ton hybrid servo hydraulic punching head, 60-in. Y-axis and rotation axis for all tools. Tools are turned at a rapid rate by high-speed, maintenance-free torque motors. Able to form large parts, the machine’s design eliminates turret wear due to off-center loads and can provide parts that are scratch-free. The system’s new Wilson 241 or Mate NEXT tooling systems eliminate the need to align tools and reduce tool prep time to less than 60 seconds. The ability to rotate tools also reduces the number of tools a fabricator needs by 40 to 70 percent. Instead of purchasing additional tools to accommodate a redesigned part, an engineer can simply program a different tool angle.

“When it comes to reducing punching costs, fabricators need to consider how they can reduce the price of the final end product,” says Hanif Esmail, general manager for Haco Canada. “To reduce price-per-part, fabricators need to put as many parts on a sheet as possible but also consider technology features that can reclaim production minutes and reduce maintenance.” Positive tool clamping eliminates the need for retractor springs and the added costs of replacing them. Programmable clamps allow an operator to reposition a piece without material waste. Intelligent software permits auto-nesting while tool indexing allows programs to be rotated to any angle during nesting for maximum sheet usage and reduced scrap.

The ability to create a full sheet design without impacting sheet metal integrity attracted the attention of Riverina Allweld. The fabricator, based in Deniliquin in southern New South Wales, Australia, produces toolboxes for utility vehicles, framework for relocatable buildings and supports local general engineering projects. Government contracts make up the bulk of Riverina’s work. The fabricator installed a Haco Q3 punch with a round automatic tool changer and indexable punching head, as well as the company’s offline software for 3-D modeling. 

“We needed the ability to perform variable depth punching, as well as tap holes and louver vents for our toolbox designs,” says Simon Thomas, owner of Riverina Allweld. “We weren’t able to make these parts with a plasma or laser cutter because they are three-dimensional. The Haco Q3 punch offered us the versatility to perform different operations. The software took into account sheet metal integrity and helped us maximize strength while creating a full sheet design.”

Flat and 3-D forming

Riverina designs its products in-house with the software, which provides 3-D modeling allowing the designer to flatten and unfold a drawing for use in both the CNC punching machine and a Haco press brake. “The software supports the accuracy we need to produce our components,” says Thomas. “The 3-D capability also allows an operator to form fully finished three-dimensional parts,” says Kyle Siebert, sales manager, Haco Canada. “With this type of forming, a fabricator can decrease material thickness by up to 20 percent while retaining material strength.” 

With the punch’s auto-indexing, Riverina can rotate all of its tools. “It takes just 120 milliseconds for a 90-degree rotation,” says Thomas. “This allows us to increase the use and flexibility of our tooling and we’ve been able to significantly reduce the number of tools we need to make a finished product.” Lack of movement and deflection in the automatic tool changer along with direct positive clamping allows fabricators like Riverina to achieve better cuts, fewer burrs and longer tool life. 

Intelligent software helps fabricators in the U.S. cope with the current shortage of qualified, experienced workers. “Haco took the skill set of a highly trained operator and integrated them into its software and hardware to simplify operations,” Barbero says. “Our software offers programming that can automatically optimize punching sequences and assign the proper tools for the job. The operator doesn’t need to have an understanding of the tools relative to the geometries. The software calculates path optimization and stroking sequence.”

Helping fabricators reclaim production time, trim costs and build a better bottom line continues to be the objective behind Haco’s development of technology solutions. “Having a machine with a flexible tool system leads to tangible cost reductions at the end of the day,” says Esmail. “But paying attention to all aspects of the production process can add to those cost reductions. It can be as simple as using a loading and unloading system so you aren’t tying up multiple operators to manipulate big sheet sizes, or making regular use of automatic tool lubrication on the machine and tool grinding to dramatically increase tool life,” he continues. “Our job is to assess a fabricator’s requirements and help them understand how technology can take care of the details while they focus on the jobs coming through the door.” FFJ

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