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Robotic Welding Cells Raise Capability, Productivity at Truform

April 1, 2022
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Efficiencies gained in automated fabrication key production gains while allowing the Tennessee manufacturer to expand its automotive and appliance work, and add commercial-product fabrication.

In a late-2017 visit to Truform Manufacturing LLC in Dickson, TN, MetalForming reported on installation of a 660-ton Stamtec mechanical press to take on new automotive work. Following soon after came the install of two more Stamtec presses (another 660-ton as well as a 330-ton model) to provide additional capacity and redundancy in stamping operation, ensuring that automotive and appliance customers receive the parts they need when they’re needed.

1-Arc-Welding-Truform-overhead-robotic-cells“For every piece of equipment here, contingency backup is important to us,” says Paul Beaton, Truform vice president. “All through the COVID pandemic, we’ve been able to avoid customer disruptions of any type and have maintained 100-percent-on-time shipping. That’s saying something, and it’s all due to the dependability and interchangeability of our equipment.”

With this compatibility and interchangeability in its stamping department, Truform has moved to do the same for welding operations, according to Mart Rowe, Truform general manager, through the addition of 12 ABB FlexArc robotic gas-metal-arc-welding (GMAW) cells. This led to another MetalForming visit this past February. Truform installed its first FlexArc cell in 2003 and replaced that in late-2017 and 2018 with eight cells, moving beyond the initial cell and manual welding to meet high component volumes for automotive contracts. The company added four more cells in 2020.

2-Arc-Welding-Truform-robotic-cell-closeupThe robotic-welding addition signifies Truform’s evolution in size and product mix. Formed in 1999 with two 200-ton stamping presses in a 20,000-sq.-ft. plant, the company set about expanding, most notably after its purchase by Sisler Manufacturing Group in 2012. Then, owners Jon and Brett Sisler, experienced in the appliance industry, turned Truform from a 100-percent automotive-supply business to half appliance, half automotive by 2017, operating in nearly 100,000 sq. ft. under roof in adjacent buildings. Capabilities grew, too, with about 175 employees across two shifts providing progressive-die stamping, welding and assembly. The presses installed in 2017-18 supported new automotive work that boosted the company’s automotive production share to 70 percent.

A production snapshot today reveals further company growth, as Truform produces to the tune of 40-percent automotive and 40-percent appliance in 137,000 sq. ft. of space in two adjacent buildings. The remaining 20 percent dedicates to a new stream: fabrication of hospitality foodservice and pool equipment, according to Beaton. Here, Truform has invested heavily in assembly operations and lines for appliance hinges and the like, and in a full all-Amada fabrication shop with sheet metal fiber laser-cutting and punching machines, and press brakes.

3-Arc-Welding-ABB-MIller-Truform-Power-Supply“This includes huge volumes of pool heaters, smoker bases, griddles and fryers,” he says, listing just some of the end-use products from parts and assemblies produced in the company’s new fabricating and assembly operations. “This gives us a hedge against the rollercoaster nature of automotive supply. Our footprint expansion results mainly from the newer fabrication operations, and we’ll be expanding again to handle increases in orders for commercial appliances.”

Cell Features Aid Productivity

Let’s return to robotic welding, which Truform uses to meet automotive demand. In each FlexArc robotic welding cell, which can work with equipment from a variety of vendors, ABB robots interface with Miller Electric weld controllers.

4-Arc-Welding-tool-fixtures-Truform“We have tried others over the years,” Beaton offers, “but have experienced the best results with the ABB-Miller setups.”
The high number of welding cells added at Truform obviously boost productivity, but so, too, do cell features. For example, the FlexArc configuration allows an operator to load or unload components on one side of the cell while the robot welds on the other. Another productivity aid: the “bullseye,” as Beaton calls it.

“This feature calculates the tool centerpoint,” he explains. “As someone performs preventive maintenance on the cell—changing tips or nozzles, for example—the welding end point can shift. But using the smart bullseye routine, the robot calculates the correct centerpoint to properly run the job without requiring reteaching. That’s a key feature for us.”

Such features enable more work, and with so many jobs running through the cells, the ability to switch from one to the next efficiently becomes paramount.

5-Arc-Welding-Truform-Amada-fabrication-press-brakes-laser-cutting“Just like with our stamping presses, we’ve set up our robotic welding cells with quick changeover,” Beaton says. 
To accomplish this, Truform designed custom welding fixtures for each job, with quick-connect/disconnect electrical and pneumatic connections.

“When we plug in those connections from the fixture decks,” he explains, “the robot control knows which welding program to call up.”

And, each robotic welding cell can accommodate any fixturing.

“We can place any fixture deck on any robot out there,” says Jody Crumpton, Truform manufacturing manager. “We don’t run every job on every robot, but for redundancy and contingency, we have that ability.”

Plant-floor operators, too, demonstrate flexibility and contingency capability through common platforms and Truform’s cross-training efforts.

“Our workforce can run any one of our 14 robotic welding cells (the 12 ABB cells and two other cells, one each from OTC Daihen and Yaskawa Motoman),” Beaton says. “The robotic welding cells feature common controls and common tooling decks. And, brought about due to the pandemic, our team is cross-trained to run commercial-appliance and assembly operations as well.”

While operators and tooling decks can run on any robot, Truform tends to partition its robotic welding work according to the type and size of welding wire needed, with 40 percent of the robotic cells dedicated to welding mild steel, for automotive steering members, and 60 percent to stainless steel, for exhaust components.

Focus on Mistake-Proofing

Parts stamped at Truform represent the vast bulk of nourishment for the hungry robotic welding cells, with poka-yoke mistake-proofing and error-proofing mechanisms helping to ensure quality throughout welding operations.

“Poka-yoke is very big for us,” says Beaton. “We try to incorporate poka-yoke mechanisms in our weld tooling as much as possible to enable in-process inspection. Sometimes, heat generated by welding prohibits the use of sensors, so we have employed vision systems on occasion, which have worked well.”

Inhouse Capabilities with Integration Assist

With a fully stocked toolroom and experienced tool designers and builders, Truform fabricates a good portion of its weld fixturing inhouse depending on capacity and workflow, according to Beaton and Crumpton.

“Our tool designers can design the fixtures using 3D CAD programs, then our machine shop uses our wire-EDM, CNC mill and conventional NC machines to build them,” Beaton says. “Our inhouse CMM then verifies everything. From there, controls engineers wire up the interfaces and teach the robots to the new fixtures.”

While Truform often integrates new welding fixtures with the robots, the robot cells themselves initially are installed turnkey, already integrated with GMAW setups and power supplies.

InMotion LLC, an ABB system-integration partner, has supported design, installation and operation of the welding cells at Truform, dating back to the initial FlexArc installed at the company in 2003. Besides assisting with Truform on the weld fixtures, InMotion also performed weld-cell wiring hookup and weld programming.

“Designing all of the fixturing as well as its quick-change capability was the main challenge,” recalls Bryan Brewer, InMotion partner. “Each fixture contains different numbers and types of sensors, switches and valves, so it’s challenging when switching from one fixture to another in a weld cell to ensure that everything works well together controls-wise.”

Beyond just the controls, Truform has invested to ensure that everything works well together, with smooth routing of material and parts through stamping, welding, fabricating and assembly operations, and with in-process inspection ensuring that quality parts and components leave the company’s plants on time. MF

Industry-Related Terms: CAD, CNC, Fixture, Lines, NC, Point, Run, Stainless Steel
View Glossary of Metalforming Terms

 

See also: ABB Press Automation Solutions

Technologies: Pressroom Automation, Stamping Presses, Welding and Joining

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