Software innovations help manufacturers eliminate part damage by identifying crush zones around formed features

April 2017 - When it comes to cutting sheet metal, fiber lasers are taking center stage these days, but CNC punch press manufacturers aren’t flustered by that fact. “Punching is not going away,” says Kevin Keane, SigmaNEST product manager for SigmaTEK Systems. “It is still a relevant technology.”

Despite fiber’s star status, laser cutting can’t handle some processes, such as the forming operations required to produce features like strengthening ribs, louvers, lances and hook mounts. Thread cutting and progressive metal deformation also require the touch of a punch press. Production costs are lower and the footprint of a punch press is smaller than that of a fiber laser. 

“Tooling has advanced as well and, in many cases, the CNC punch presses that are sitting on production floors are already paid for,” Keane notes. “Customers aren’t necessarily looking to invest in new capital equipment. They just need to be able to run their existing punching machines better. That’s where continuous improvement initiatives come into play and we believe we offer that.”

The Cincinnati-based company serves customers ranging from job shop startups to large manufacturers with its robust CAD/CAM, nesting and automation software solutions. In addition to its development of SigmaTUBE, Sigma- BEND, SimTrans and SigmaMRP, the software developer’s SigmaNEST program offers smart nesting systems for fabrication operations.

The hits in orange (above) were automatically detected by SigmaTEK's software as a threat to a part feature, prompting it to segregate and resequence hits to avoid crushing formed attributes like the louvers (below).

Continuous improvement

SigmaTEK identified a niche space that wasn’t being filled by other software products on the market. “Our customers were tired of experiencing part damage,” Keane says. “Historically, software relied on experienced programmers with the skills to manually sequence punch hits so that formed features close to a part’s edges were not disfigured when the piece was punched out. Traditional punch users had a job shop background and knew how to do these things. With the skills gap, it is becoming harder and harder for fabricators to find employees with these capabilities. Yet a lot of software on the market still relies on manual programming.  We wanted to solve that problem.”

The company recently conducted field tests on some new features it developed as part of a software upgrade to be released this spring. Pre-Form Parting identifies hits that will come too close to a formed feature before it happens. Punch hits can then be resequenced to avert potential damage to the material.

“If I’m punching a part with formed features such as louvers, the Pre-Form Parting feature allows me to immediately identify the crush zone around that attribute,” Keane explains. “I can automatically detect, identify and segregate punch hits which may damage the formed feature and ensure it remains undamaged.”

The first time SigmaTEK field tested this new capability, beta users were pretty excited about its potential, he says. “We were punching parts that previously required programmers to perform multiple steps to ensure safe processing. It’s a huge cost saver for customers because they aren’t scrapping parts and tooling.” Time savings are also expected to be significant, “particularly time spent programming.”

Automated safety

According to Keane, the conventional approach to punch press programming was time consuming and error prone. “Pre-Form Parting provides an automated measure of safety that until now hasn’t been available,” he says.

Another feature SigmaTEK is readying for launch is automatic machine slow down. “We all know from experience that the moving sheet on a punch machine gets very fragile as the job progresses,” Keane explains. “It is bad enough when parts are tabbed in place, but it can be even worse when there is an automatic part removal device attached to the machine for a stacking system.”

The purpose of this feature is to slow machine speed as it approaches the end of the part without having to run the entire job at a lower speed. The benefits include increased part quality, and improved sheet and skeleton integrity. Users will be able to slow punching via automatic or interactive mode. The ability to reduce punching speed also curbs vibration and oscillation during part processing. 

“Its standard to punch internals and then move to the part’s outer boundaries,” says Keane. “With three sides cut, the punch press has less material to hold the piece with, making it possible for the part to move. We’re able to prevent this by slowing the machine down automatically.”

This ability should help to improve part quality and ensure safe removal of the finished part. This is especially critical with automated systems that may be running unattended. “The technology breakthrough is that we have built this margin of safety into the software as an automatic feature,” Keane says. “This is an advantage for the company with a machine operator or programmer who has less experience.”

Software advances aren’t the only thing fabricators should seek out when trying to improve CNC punch press operations. SigmaTEK’s engineers have a combined 100-plus years of experience. “We are a global company and this means that our engineers have a front-row seat to observe and evaluate the most promising new trends, whether they come from right here in the U.S. or further afield in Europe or Asia,” Keane notes.

Looking ahead

SigmaTEK is monitoring developments with the Internet of Things (IoT) and how this and other components of digitized industry will impact manufacturers. In May, SigmaTEK Academy begins, covering IoT, industrial automation and the smart factory. The three-day event is designed to equip manufacturers to navigate a changing landscape.

The software provider adds that its most valuable assets are its employees and its customers. “On the customer service end, our experience allows us to shorten the learning curve for our customers,” Keane says. “On the product development side we welcome, invite and cultivate customer input. We are a conduit for good ideas. By listening to and working with our customers, we build better software.” FFJ