A helical auger flight, used in a screw conveyor, takes a manual welder 45 min to hard face. The Motoman ArcWorld 1000 takes only 15 min.

Tucker's boosts flexibility by using two identical robot cells, each handing physically demanding work that exposes welders to fumes.

Tucker's Machine & Steel Service Inc., Leesburg, Fla., is a machine and fabrication shop with 50 to 60 people and a high-tech equipment mindset — "We were one of the first companies in Florida to use MIG guns," says Matt Tucker, project engineer. Tucker's product range includes weldments that are cast into prestressed concrete products and a machine that moves concrete with a series of 14-in. diameter, 14-in. tall helical auger flights. Making these parts is tedious. "People get tired and bored welding thousands of the same parts, but robots don't," reports Tucker. So, the company installed two Motoman ArcWorld 1000 robot cells.

The helical auger flights are high-wear items, so the company places a 2-in. wide circular-weave pattern of hard weld the entire length of each flight face. This work is so physically and mind-numbing that employees viewed it as punishment. And because the flux-cored wire used produced hazardous fumes, the parts had to be welded under a cramped fume extraction hood.

The ArcWorld cells reduce workers' up-close exposure to welding fumes and improves their safety. In addition, the cells' fume extractor hoods boosts the entire plant's air quality. Robots also don't get tired and bored. They complete in about 15 min what a welder took 45 min to do, reports Tucker.

Other benefits include weld quality, accuracy, repeatability, and increased production. Tucker explains: "Since many of our products are directly related to the structural integrity of buildings, our welding quality requirements are pretty stringent. Robotic welding gives us the accuracy, repeatability, and high production rate needed to meet customer requirements. Many of the weldments are made from hot-rolled items, such as flatbar and rebar, that have a large dimensional tolerance and vary in size from batch to batch. Because we design and build all of our jigs, we can accommodate the fixturing for these variances."

Motoman customized the workcell's 661.5-lb payload 180° indexing positioners with 72-in. diameter tabletops. The cells also include application-specific EA1400 Expert Arc welding robots with integrated upper arm cabling that reduces interference and helps simplify programming.

"We really liked the Windows CE-based programming pendant used with the NX100 controller. The robots are easy to program and adjustments are effortless," says Tucker.

In keeping with its high-tech mindset, Tucker's says it used metal-cored wire and digital welding power source technology before they became hot topics. "Today, we use Metalloy 76 weld wire for our processes because it has a high deposition rate that allows use to take advantage of the robot's speed. And our two ArcWorld 1000 cells include 450-amp Miller Auto-Axcess digital power sources," continues Tucker.

Motoman Inc.
West Carrolton, Ohio
motoman.com