Making robotic bending work for the job shop

Robots found in front of press brakes are not a totally unique sight. Some job shops have found the right mix of products and volumes to justify their use.

A majority of job shops are still leery, however. They are concerned about the time it takes to program the robot and how it might fit into their high-mix, low-volume world of manufacturing.

Steven Lucas, LVD’s international product manager for press brakes, said his company recognized these concerns and has spent the last couple of years trying to address them. The result is the Dyna-Cell, a 16- by 16-foot robotic press brake cell that will make its North American industry debut at FABTECH, Nov. 11-14, in Chicago.

“We have worked to eliminate the need for knowing how to program a robot,” said Lucas at the company’s Technology Day event at its North American headquarters in Akron, N.Y., on Sept. 17.

Programming has always been a turnoff for many fabricators, who either don’t have a lot of experience with robots or who know well just how long it could take to program a robot to complete one task. Lucas estimated that a fabricator could spend from one hour to 90 minutes programming a robot for a typical press brake job. That sort of time span can really affect the cost-per-part scenario for a job. The more time assigned to a job that doesn’t actually involve making the part, the more costly it becomes.

Lucas said that LVD has achieved its goal of creating a robotic bending cell that takes less than 10 minutes to program and less than 10 minutes to set up and produce the first part. He estimated that it takes about two minutes to load a file into the company’s CADMAN-SDI software, which takes the files and stores them as Open Sheet Metal in the software’s database, and create the program in the bending software, CADMAN-B. Another eight minutes is required to program the robot, which is also done in the bending software. The remaining 10 minutes is spent setting up the tooling and proving out the first part, which should go smoothly based on the software’s 3D simulations.

“No robotic knowledge is required to run this cell,” Lucas said.

The cell comes with a Dyna-Press Pro 40/15 press brake with 40 tons of bending force and a 59-in. working area. It can bend parts at speeds of up to 1 IPS, according to the company. A Kuka robot with a 26-lb. payload also is included.

Lucas said that LVD engineers focused on designing a “universal” gripper that could work with as many parts as possible. This was important because, again, time can be eaten up with a robot having to switch gripping tooling between small-volume jobs, which is time that the robot actually could be bending parts.

The robot’s gripper bends on three different sides of a part without regripping. Suction cups are activated according to part size. The gripper is designed to handle part sizes from 1 in. by 3.9 in. up to 11.8 in. by 15.7 in. and up to 6.6 lbs.

Steven Lucas of LVD Strippit demonstrates how a file is imported into the CADMAN software and how it is then used to program the robot and press brake in the company’s Dyna-Cell automated bending cell.

In the event a fabricator finds it much quicker to bend a part manually, the robot can be depowered, and an operator can gain quick access to the front of the press brake for the job.

Matthew Fowles, LVD’s group marketing manager, said that future editions of the Dyna-Cell will include the company’s Easy-Form® bending correction technology, which uses a laser to check in-process bend angles and adjusts the ram and punch positioning to deliver the correct form. LVD also is considering this automated approach for larger press brakes, but will commercialize the technology only if it is cost-effective enough to compete with manual bending of larger sections.

The robotic arm presents the metal part to the press brake’s backgauge as it works its way through one of three different jobs demonstrated for visitors at LVD Strippit’s Technology Day on Sept. 17.