Production Machining

JUN 2018

Production Machining - Your access to the precision machining industrial buyer.

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Mr. Wiltsie has also spearheaded pick-and-place automa- tion for loading and unloading for both lathes and mills on the shop floor. Basically, these units were mechanical shuttle loaders/unloaders designed to relieve the monotony of using an operator to perform the tasks. ey were pretty much fixed automation with little flexibity. Robots represented a logical move forward for Vanamatic. After seeing a cobot (a robot with proximity sensing capable of safely working next to a person) being demonstrated at a trade show, Mr. Wiltsie could see the technology had caught up with his shop's need. A six-axis articulated arm, working next to an operator, without the need for a safety cage was perfect. And Rich Lindeman's assembly station was a perfect place to start. Vanamatic's first cobot was Ethel. She was named by her handler, Mr. Lindeman, who recently celebrated 50 years of full-time service with the company. For the assembly opera- tion that Rich and Ethel were paired to do, perhaps Rich saw himself in the roll of Lucille Ball and his cobot as her stalwart friend, Ethel Mertz, working the chocolate candy conveyor. e assembly task that Mr. Lindeman would have performed is an eight-step process that starts with a pallet of 144 parts. Mr. Lindeman picks up the part, checks a critical length measurement on a gage, assembles a small O-ring on the end of the part, blows out the ID, pushes a spacer over a set of threads to seat against a hex, verifies the assembly and places it in a package for shipping. According to Mr. Wiltsie, Vanamatic's plant manager, "Rich has no problem doing this and has successfully done this job for some time. It's not a matter of performing the task once; it's a matter of performing it 500,000 times, which was the order quantity for this assembly," he says. "It's a line-ready part for a fuel injection system and has to be right. I'm only 40 years old and did the assembly myself. I was achy after a few thousand and with less than perfect quality. Meaning no disparagement of Mr. Lindeman, assembly for this particular order was not intended for a human, and as I found out, was not humane, either." :: Vanamatic's first cobot, Ethel, was installed at this in-house designed and built assembly workstation. Ethel is a UR3 model built by Universal Robots. It's the smallest cobot UR makes and has a range of motion that is almost equivalent to a human's. e payload is 6.6 pounds, radius reach is 19.7 inches and the footprint for the unit is 5.9 square inches. However, for Vanamatic's fuel injector assembly application, the robot was only the beginning. Ergonomics are an important consideration for arranging a workspace for a human worker. Considerations include where the work enters the activity zone, placement of ancillary equipment such as measurement gages for this assembly operation, where the O-rings and spacers are placed in relation to the assembly activity and orientation of the machined parts as well as the location of the outbound packaging. While ergonomics are important for Mr. Lindeman, it's of critical importance for Ethel. She is smart, but lacks the ability to make subtle motion change decisions and the intelligence to adapt beyond her programming, even though she does include subroutines to deal with missing O-rings or spacers. at will be solved with vision systems in the future. Meanwhile, the use of "poka-yoke" for the incoming trays is a simple, reliable means of making sure Ethel's program gets off to a good start in the right spot every time. :: This completed assembly is used in a fuel injection system. In-House Integration productionmachining.com :: 33

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