Above: Central Tube and Bar recalls stored programs, making repeat cutting jobs fast and efficient.
With BLM Group’s technology, tube processor perfects motorized electric shopping cart design
October 2013 - Some might call it a textbook case of reshoring manufacturing. But when Assembled Products Corp. began rejecting defective tubular parts from its supplier in China—to the tune of 20 percent—quality control was the company’s real concern. Problems with the processed parts ate into cost savings that originally made outsourcing to China sensible. Even when problems were supposedly ironed out and quality control improvements were made, they proved temporary.
Of course, APC isn’t the first U.S. manufacturer to outsource work. Plenty of material, equipment and cheap manpower have made China a manufacturing powerhouse. China offers enormous cost savings that make long lead times justifiable. It makes sense, and works out great for companies. Except when it doesn’t, as APC was learning.
Based in Rogers, Ark., APC’s best-known product is the Mart Cart, the electric motorized shopping carts used by customers who have difficulty walking up and down grocery store aisles. The company’s founder, Bill Sage, came up with the idea in the 1980s after noticing how grocery shopping had become increasingly hard for his grandmother. Today’s Mart Cart chassis, seat, basket supports, rear bumper and gooseneck steering column are assembled from steel tubing into a frame. Tubing keeps the carts strong, lightweight and reasonably priced, but with intricate bends, lengths and angles, the tubes need to be precisely formed and fabricated.
Initially, APC contracted domestic fabrication shops for the tube work. But when those suppliers hit financial trouble, APC had little choice but to look elsewhere for its Mart Cart tubular frames. The savings of sending the work to one reputable tube supplier in China were remarkable. The supplier produced quality samples and met cost targets. But after encountering quality problems down the road, cost savings disappeared.
In 2008, APC’s fortunes changed. Dustin Ward, president of steel tube supplier and processor Central Tube and Bar Inc., Conway, Ark., visited APC to show its engineers what Central Tube and Bar was capable of, and hopefully drum up some business. Ward opened his laptop and played a couple videos of Central Tube and Bar’s tube lasers deftly making cuts and holes in an array of steel tube. Piquing APC’s interest, Central Tube cut some sample tubes.
Not long after, APC redesigned the gooseneck steering column, adding cutouts and tabs that could be aligned for consistent fit-up if made with the accuracy of a tube laser. Those designs went to Central Tube and Bar for prototypes, which it processed on state-of-the-art tube lasers. The results were impressive.
“They matched the drawings perfectly,” says Steve Conrad, chief manufacturing engineer at APC. “We tested the fit up, and it was dead on and repeatable. In fact, we figured you would no longer need a welding fixture to hold the handlebars to the gooseneck. They mated so well, you could just snap them together and start welding.”
At the heart of Central Tube and Bar’s operation are BLM tube and pipe processing machines. BLM Group USA Corp., Wixom, Mich., sold Central Tube and Bar its first tube laser, an Adige LT712D, in 2006 after demonstrating it at Fabtech. The following year, Central Tube and Bar bought the BLM Adige E-Turn 50 millimeter tube bender for a job involving school bus seat components and then an Adige LT8 tube laser in 2012 to expand its services in Tulsa, Okla., where Central Tube and Bar’s second plant is located. The lasers make short work of jobs traditionally done on separate machines, such as sawing, drilling, punching, notching and deburring. The CNC E-Turn bender brings accuracy and consistency to the often prickly job of tube bending.
BLM’s technology has simplified several aspects of Central Tube and Bar’s operations, making the processor more efficient and giving it the capability to take on challenging jobs. Bending tube is more of an art rather than a science, says Ward. It used to take lots of time and material to set up jobs. BLM’s technology drastically cuts the time needed to do so, resulting in reduced scrap. One way Central Tube and Bar accomplishes this is by using the BLM tube laser to etch a specific mark on a part that needs bending after cutting. A camera on the E-Turn bender then locates the mark and positions the tube with extreme accuracy for repeatable bends.
“Once this function is established in the machine’s program, you get that the repeatability and consistency simply by recalling the program. This is especially beneficial when prototyping parts,” Ward says. “By taking the conventional methods of setting up a job, which was always prone to human error, and making it a machine function based on a program, we get repeatable, consistent parts on every run from our BLM machines.”
The BLM LT712D is a three-axis machine with a 6 inch OD capacity. It’s a proven producer and “bulletproof,” Ward says. The beefier LT8 has 5 axes with an 8 inch OD capacity. The additional axes allow for bevels and true miters that the LT712D cannot make. Central Tube and Bar’s BLM machines are networked, making it easy to import programs and communicate between facilities. “We can program and run any of our BLM tube lasers from any location via this network. Guys in Tulsa can program machines in Conway and vice versa,” Ward says. If needed, BLM can remotely connect to the machines to diagnose, repair and deal with any issues.
Another way BLM helps is with training. Central Tube and Bar has extensive in-house training programs for the operators of these advanced machines, but BLM also avails its training facility outside Detroit for users.
Selling advanced capability
“Honestly, once you’re up the learning curve, operating these machines is pretty straightforward,” says Ward. “But a big challenge was educating customers on what is possible with tube lasers. When we first started selling these services there was disbelief that what we were saying could actually be done. We spent many hours demonstrating to customers how we could make their products better while reducing their overall costs. That has changed somewhat as the market becomes more aware of our capabilities and expertise. We now have customers seeking us out to help them address their challenges.”
When Central Tube and Bar first proposed processing the 16-gauge-by-1-inch and 14-gauge-by-1.25-inch square tube for the Mart Carts, Ward knew he had to charge more than the original Chinese supplier. But he also knew he could deliver within two weeks instead of 15, and ultimately he delivered product with a reject rate of less than 1 percent.
“No company is perfect, even with the best machines. But Central Tube is genuinely concerned about what we’re trying to achieve,” says Don McKenzie, purchasing manager at APC. “The difference is they take it to heart and do everything to make the product better.”
One example: Central Tube and Bar came up with a better way to attach the Mart Cart’s rear bumper. Originally, 3⁄4 inch round tube was bent into a wrap-around rail and welded to the chassis as a bumper. However, if the bumper was damaged in service, field repairs were costly. Central Tube and Bar came up with a way for the bumper to fit into cut holes in the chassis, and then get bolted on. Rather than the service tech having to first grind off welds to remove a crushed bumper and then weld on a replacement, he now only needs to loosen four bolts to swap out bumpers.
In terms of meeting APC’s cost goals, Central Tube has proven its value and then some with the help of its BLM tube processing technology. The delivered price of the Chinese frame was certainly cheaper on paper, explains McKenzie, but on the assembly floor, the Central Tube frame offers better value and superior quality.
The Mart Cart was recently comprehensively tested by Underwriters Laboratories. That resulted in the Mart Cart being the first motorized shopping cart to bear UL’s seal as fully meeting standards for its product category.
“You can bet Central Tube and Bar contributed to that,” says McKenzie. “We are glad to have them part of our team, and proud we were able to bring this manufacturing work back to the States, especially to our home state of Arkansas.” MM
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