Gymnastics for Fabricating
- January 22, 2012
by Shop MT Staff
If you’re a metal fabricator, bending equipment is essential to your shop. No matter how you cut the metal, at some point in the operation it needs to be formed into a product. Like most fabricating equipment, bending technology has undergone significant changes from basic manual machines to advanced CNC fully automated systems that operate within a fabricating cell.
There are many suppliers in the market who sell bending equipment. Some, like Salvagnini, specialize in the technology. Indeed, the Italian company, with North American headquarters in Hamilton, OH, lays claim to being the inventor of the panel bender in 1977. According to company history, Italian native Guido Salvagnini wanted to improve the old style manual press brake bending process and created the P4 panel bender, giving fabricators more flexibility in the fabricating shop.
Shop Metalworking Technology spoke with Salvagnini North America’s president Bill Bossard about changes in bending technology.
SHOP MT: What has been the most significant changes in bending technology in the last decade?
Bill Bossard: When Salvagnini introduced its panel bender in 1977, it was the first time the world had seen a panel bending machine. At that time no one was using computers and the first CNC machines used teletype punch tape. Today, the advent of the Internet, micro processors, advanced CNC controls, 3D CAD/CAM drawing systems and other advances have changed and improved the bending process.
Shop MT: What specific changes have helped improve productivity on the shop floor?
Bill Bossard: There is a lot of magic involved in what bending machines can do today; that’s what I’d call it. The fundamental premise of our bending machines is to eliminate your set-up times. This may sound simplistic and you may think this isn’t a big deal, but in talking with people that run press brakes you see that many don’t recognize how they can make improvements. I was speaking to a group from Canada recently and this company has five press brakes. On a daily basis, it has more than 150 different set ups. I asked them ‘how long does it take?’ And they said ‘anywhere from five to 30 minutes. When you’re setting up, you’re not bending parts. What would happen if you could automate your bending with zero set-up? We can offer this because of the rearrangement of tooling done via the CNC control. The system rearranges the tooling in eight seconds and by the time you’re loading the next part in the machine, the machine is set up with the program and is ready to go.”
Shop MT: Bending machines have evolved in recent years from hydraulics to hybrids and all electric machines. Is one technology truly better than the other or is there a place for each?
Bill Bossard: A lot of precision bending work that is done use exclusively hydraulic machines from 40 ton 80 tons. Electrics are typically faster and more accurate and they are more energy efficient as they don’t have the pump and motor going all the time. But today’s hydraulics are also improved and there are many energy saving cycles incorporate into machines. So during non-use time, the hydraulics will shut off and when ready to go again, they’re up and running. You don’t shut down complete with hydraulics and there is a low volume circuit, but the machines are quick to ramp up again and take less than a second to get back up to full power.
Each type of machine offers benefits to fabricators. Whether its electric, hydraulic or hybrid, the first issue is size and thickness. Biggest with electric machines is 80 ton and if you go with bigger parts, you need to move to hydraulics. Electric machines will beat the pants off hydraulics on pieces per hour [faster] and are more accurate, but they’re designed for low tonnage. If you use an electric machine for high tonnage, the size of the motors, ball screws and reciprocating nuts become too expensive.
Shop MT: What’s the next technological development in bending?
Bill Bossard: There are three areas where I see change. The time factor is becoming more of a focus. People are beginning to understand the process starts in the office when you get the order from the customer. Companies are more focused now on getting the order generated faster to the shop floor using integrated 3D programming to create part drawings. A second focus is automation. Fabricators are asking ‘how do I move my parts incrementally without having to touch them?” And the third issue, particularly with bending, what can you do to eliminate setup and if you can’t eliminate, what can you do to mininize.