Above: Versatility and variety of tube profiles cut by tube laser.
Manufacturer finds laser tube cutting both simplifies and amplifies production of fireplace heating elements
August 2015 - A company building Heat-n-Glo gas fireplaces since 1975 has grown to operate the largest North American factory for such products, employing roughly 500 people in two plants totaling 300,000 square feet.
The demand for fireplaces, especially in new construction, has prompted the company to upgrade its tube cutting capabilities.
Hearth & Home Technologies, Lake City, Minnesota, manufactures the Heat-N-Glo, Heatilator, and Quadra Fire brand fireplaces. It forms and cuts tubing and welds it to plate to assemble the natural gas-fueled burner tubes in the fireplaces. The plant produces between 700 and 1,000 fireplaces per day, Product Line Manager Curtis Klein says.
Laser head cutting gas port holes in burner tube.
“Our main runner is 1-inch aluminized carbon steel with a 20-gauge wall [0.33-inch-thick],” says Nate Harnly, H&H’s engineer and hearth expert. “We also use stainless steel at 1-inch-diameter, 0.35-inch-thick wall. The largest diameter used is 1.5 inches, also with a wall thickness of 0.35 inch.”
Burner tube production starts with a raw 10-foot-long tube, which is cut with the laser, moved to a tube bender and followed by a cutoff saw. “Then we have swedging [changing the tube diameter, usually just at the tube end, in order to have it fit into another part] and welding operations. We weld the tube to plates, and run a press brake operation to flatten the tube,” Harnly explains.
“Not every tube undergoes the same process but all do go into the laser cutting system,” which H&H purchased from AltaMAR, Fridley, Minnesota.
“The tube laser allows us to add value,” he continues. “We were using coping tools, but hard tooling is very expensive and requires extensive maintenance. We used to cut a blank, bend it and cope it. But with the laser machine, H&H starts with any and all shapes, cuts and bends and has “a finished product out of the saw, which is much more productive. [Because] the laser is much more concise, we produce less waste.”
Tube auto-magazine loader is set up to run ‘lights-out’ without an operator.
Furthermore, “We are doing things on a fiber tube laser that we weren’t doing before. We have more flexibility to try new things.” The AltaMAR “speeds up the design cycle and can manage a greater variety of designs.”
Before installing the laser tube cutter, “If a designer came in and wanted something done with a hard tool, it would take us a long time. Now we can laser fabricate prototypes quickly for them,” Harnly says.
Klein agrees, noting that although the AltaMAR was installed in the first quarter of 2015, full-scale production is just “kicking off. We are still developing applications. We will grow with it and we will introduce new parts into the system.” MM