A simple leap of faith helps a lawn tractor manufacturer make a huge leap in bending efficiency
February 7, 2006
Simplicity Manufacturing Inc. of Port Washington, Wis., needed new press brakes because it was about to increase its laser cutting capacity. The outdoor power equipment manufacturer turned to a vendor of Turkish-built press brakes for help and found the answer for which they were looking.
|Low-volume products, such as this zero-turn-radius lawn tractor with a 21- or 23-HP engine, kept Simplicity Manufacturing's laser cell busy, but also created a bottleneck at the company's old press brake.|
For almost 70 years, Simplicity Manufacturing Inc. has worked to live up to its name in the outdoor power equipment industry—making lawn and garden equipment and snowblowers that turn normally back-breaking chores into simple ones. The company's commitment to that goal has led to tremendous growth over the years and put it in a position to gobble up other regional equipment manufacturers, such as New York-based Ferris Industries Inc. in 1999 and Georgia-based Snapper Inc. in 2002. (Such growth attracted Briggs & Stratton Corp.'s attention, and the engine manufacturer purchased Simplicity in 2004.)
With such growth comes an expansion of products and a need to expand productivity efforts. But how does a company accomplish this typically bank-breaking chore? Rarely is there a simple answer for such a manufacturing dilemma.
In 1999 Simplicity manufacturing personnel got off to a good start with the purchase of a Mazak Super Turbo X48 Hi-Pro laser cutting machine with an FMS storage tower. The laser was dedicated to the fabrication of low-volume parts, particularly service parts for equipment that was no longer being sold. For the high-volume components of its mostly metal lawn tractors, a rarity in today's world of plastic lawn and garden devices, a combination of hard tooling and a stamping press still made sense, but for small jobs, the laser cutter proved invaluable.
Soon, however, small jobs weren't just for replacement parts. As product designers developed more niche products, such as a zero-turn grass cutter and a European-targeted lawn tractor, it made more sense to fabricate the parts on the laser cutter rather than invest in hard tooling.
With the volume increasing over the next several years, the bottleneck at the one existing press brake became unbearable. Simplicity's fabricating department solved the dilemma in 2004 with a new Mazak MK II laser cutter and two new Durma press brakes—a CNC-HAP 30120 and a CNC-HAP 30160—with modern control software and tooling. But to end the tale here simply wouldn't do the story justice.
|Simplicity originally purchased the Mazak Super Turbo X48 Hi-Pro laser cutting machine and the FMS storage tower in 1999 to fabricate prototype parts and service parts no longer in stock. The company soon learned that it was a great tool to fabricate low-volume parts that might have been made otherwise with a die in a stamping press..|
When the laser cutting machine and automated storage tower were purchased in 1999, Simplicity's fabricating crew got a new press brake as well. The day it was installed was probably the best day the press brake had in the facility.
First, Simplicity press brake operators struggled to keep up with the work flowing from the laser cutter.
"Our setups were elongated. Our tooling was less than desirable," said. John T. Wolf, a former fabrication engineer with Simplicity who was around for the press brake struggles. "We actually had a table on the front of the press brake. The boys would set up gauges, and by the time they were done with a setup, it was like they had built a die to put the steel into it to bend the part. It had inefficiency written all over it."
Second, the primitive DNC and the press brake never worked that well together.
"You never got the really good-quality part out of it. You could hold some tolerances," Wolf said. "We all learned to live with them."
Mike Weller of Weller Machinery Co., Pewaukee, Wis., knew of the situation intimately. He was called in to help when the original equipment dealer that sold Simplicity the press brake proved to be unresponsive.
"They had electrical troubles with it to the point that we had to work with the controls," Weller said. The press brake struggled to hold the tolerances of newer machines. Weller said the angles could be 3 to 4 degrees off from one end to the other on some longer fabricated parts.
|The two Durma press brakes with Wila tooling have helped to reduce setup tremendously for operators. Once the plan is called up on the control, the operator grabs the tooling suggested by the software, installs it in the quick-clamp tooling, and positions the steel blank against the automatic backgauges. Average setup now is about five minutes.|
The problem became exacerbated as the laser cutting machine ramped up to handle even more parts. Wolf said that when he arrived at Simplicity in 2000, he was charged with increasing production efficiency in the laser cutting cell. The machine that was designed to run 24 hours per day, seven days per week with little operator intervention was running only about 16 hours per day, five days a week, with operators frequently engaging the machine. That situation soon changed when the laser cutting machine began fabricating as many as 60 to 70 different 2-D parts for each individual niche product that Simplicity planned to ship to its dealers.
With the laser cutting machine booked solid, Simplicity's fabricating team turned to outsourcing for help.
"We outsourced, and we outsourced a lot. So I took a look at investing in another laser to put into that cell," he said.
The return-on-investment argument for a new Mazak laser was easy. The outsourcing costs were much more than the price of a new machine.
The benefit of purchasing new press brakes was less obvious, but it still made sense to anyone knowledgeable about fabricating. What was the point of precisely cutting parts if the bends weren't going to meet specs?
"We needed to take the next step, because if we were going to continue to laser-cut parts, we needed to get better at bending the parts," Wolf said.
Traditional fabricator thinking suggests that two press brakes are needed to keep up with one laser cutting machine. Wolf said he was in a unique position because only 50 percent of the parts cut on the lasers would need bending. As a result, Wolf pared his wish list down to two press brakes.
|By the time classes in offline programming concluded, Simplicity's press brake operators already had created a part catalog of approximately 700 jobs simply by logging in the job information at the machine.|
The Simplicity team began its search in the fall of 2003. They not only solicited bids from several major press brake manufacturers, but also from Weller Machinery, the company that proved so helpful with the old press brake.
Wolf clearly remembered Weller's presentation about the Durma press brakes, the Wila tooling, and the control system: "The real funny thing in this story is at the end [of his presentation] he has to say these words, 'The press brakes are manufactured in Turkey.' And I'll never forget that day because we are all sitting in the conference room and everything is good until the word 'Turkey' comes out. You can imagine. Everyone goes, 'Huh?' Everyone is used to hearing about Germany, Japan, and even Italy. And you are thinking to yourself, 'Can I picture a precision press brake coming out of Turkey?'"
The apprehension was real, but so too was the value offered by the Durma press brakes, Wolf said. The press brakes, tooling, and control package from Durma stood out very clearly from the other bids.
Luckily, Wolf and his supervisor had the chance to visit FABTECH® International tradeshow in Chicago to test out the Durma press brakes. Not only did the party from Simplicity find that the Durma press brake looked like others at the show, they discovered features that helped the equipment to stand out in their minds.
"Two things started standing out almost immediately," Wolf said. "One was the backgauge. It was heavy duty. It moved very smoothly, and the zero corners were in sync and protected. Then the Delem DA66W controller looked fascinating."
Wolf said he spent five minutes at the show programming the software to make a part and then making the appropriate bends. A quick check afterward revealed the part to be in spec.
Wolf also spent time looking at the Delem V-Bend offline software programming capabilities. He brought a file in, programmed it for the final form, sent it over to the press brake, and watched the final part being made.
"We walked away from that show and on the ride home the decision was made that I was going to recommend buying the equipment," Wolf said. The press brakes' country of origin was no longer an issue.
The press brakes were installed at the beginning of February 2005, the peak time for Simplicity's lawn tractor production. The pressure was on to get the machines and operators up and running from the start.
"We had a known 12-week delivery, but in the interim they added the second laser to their tower system," Weller said. "That happened to be a stock machine that was installed a month prior to our two Durmas showing up. So needless to say, with two lasers online and with only one old and tired press brake, by the time our machines got there, we had a gun to our head because there were blanks in containers all the way up and down the aisles in the fab department."
Installation of the two press brakes, one with a four-axis backgauge and the other with a six-axis backgauge, took three days. Training occurred on the fourth day. By that Friday Wolf said Weller and his team cut the umbilical cord. Two press brake operators on the first shift, one on the second shift, and three on the third shift started bending parts and working their way through the backlog.
Four days later the old press brake was pulled out of the building.
"The boys really liked the new press brakes. They were much more efficient in setup," Wolf said. "It's night and day in the difference."
Before the new press brakes were installed, Wolf estimated that the operators needed 25 to 30 minutes to set up for each part because a separate fixture table had to be used for each part number to compensate for the machine's inability to hold tolerances. Now operators need five minutes of setup to bend the mild steel blanks, which can range in size from 20 gauge to 1/2 inch thick.
Here's how it works: The control details the job, the operator selects the prescribed Wila quick change tooling from the nearby cabinet, the operator snaps the tooling in place, the machine then hydraulically clamps it, the backgauges position automatically, the operator refers to the graphic on the control, and the bend process is under way.
Quality improved as well. The old press brake generated six corrective actions per week, which led to rework or, in worst-case scenarios, scrap. In the months after the new press brakes were installed, Wolf could remember only two corrective actions being written up. Both were related to operators misreading prints; the new press brakes were innocent of all charges.
The controls that impressed Wolf also won over the operators, one of whom had more than 30 years press brake operation experience. In the ensuing weeks after installation when Wolf was learning the finer aspects of programming the software offline, the operators had already programmed nearly 700 parts at the machines. The part library was well-stocked by the time Wolf assumed offline control of parts programming.
Weller said the performance of the press brakes was notable, but the transformation of Simplicity's longest-tenured press brake operator was remarkable.
"When the new machines came in, it basically changed everything he had done on the old machines for the last 10 years. He was very apprehensive," Weller said. "He wasn't quite sure. Was this thing going to be really repeatable? Was it going to do the first part the way he wanted it to when he programmed it, because the other one didn't?
"After a couple of weeks he seemed to settle in and put up with it," Weller continued. "After five or six weeks of working the machine, you could see him turn, and now you couldn't pry that press brake out of his cold-dead fingers."
Simply stated, that's a happy ending for Simplicity as the company continues to grow and its manufacturing operations remain competitive.
Simplicity Manufacturing Inc., 500 N. Spring St., P.O. Box 997, Port Washington, WI 53074-0997, 262-377-5450, www.simplicitymfg.com
Delem, Luchthavenweg, 42, 5657 EB Eindhoven, Netherlands, 31 40 2552969, fax 31 40 2551923, www.delem.com
Durma/SCA Fabtool Corp., 10031 Pioneer Blvd., Santa Fe Springs, CA 90670, 800-367-6911, fax 562-222-2270, www.durmausa.com
Mazak Optonics Corp., 140 E. State Pkwy., Schaumburg, IL 60173, 847-252-4500, fax 847-252-4599, www.mazaklaser.com
Weller Machinery Co., W237 N2889-A Woodgate Road, Pewaukee, WI 53072, 800-728-6387, fax 262-523-1818, www.wellerusa.com
Wila USA, 9135 Guilford Road, Columbia, MD 21046, 888-696-9452, fax 301-490-3991, www.wilausa.com