Make no mistake, this laser solves problems
If you received a call late from an assembly line manager telling you that trailer loads of parts (which you have never seen) needing remanufacturing were on the way to your plant, you’d be concerned.
If you received a call late from an assembly line manager telling you that trailer loads of parts (which you have never seen) needing remanufacturing were on the way to your plant, you’d be concerned. If these parts were needed back within two days, you might be a little apprehensive, unless you had a versatile, high-speed 2D/3D laser system in your arsenal raring to go. Then you would know the parts could be programmed, staged, cut, and shipped on time to a grateful customer and at a profit. This scenario is not unusual for Precision Metal Fabricators Inc. (PMF), a progressive, growing Williston, South Carolina, contract fabricating shop.
For 14 years, since it’s founding, PMF has been on the lookout for new ways to meet increasingly demanding fabricating needs. And it has paid off, as today 57 employees produce $7 million in annual sales. “If we stay ahead by using the latest equipment, our market will take notice,” says John Johnson, the affable, 57-year-old president of PMF, “and that inevitably translates to more work, increased profit, and expansion.”
With 30,000 sq. ft. of manufacturing space housing an assortment of metal fabricating and painting equipment, including two lasers, PMF is a serious player.
Most of PMF’s work is two dimensional in nature but three-dimensional work is now coming on strong. “Today, it’s difficult to maintain a steady flow of profitable, conventional flat sheet work, because the competition is intense. Not so with non-standard 3D work, which has become a very lucrative niche for us-especially with combined 2D/3D part laser cutting. From NASCAR to the military market, to automotive, in rapid prototyping and production applications, 3D work is our newfound success,” says Johnson.
The engine fueling this laser boom is a Prima Domino 1530 system, installed early in 2003. “Today the Domino is cutting full tilt, 2 shifts a day, 16 hours. This one machine alone is generating around 20 percent of our fabrication business and we see no end in sight for keeping it fed,” Johnson reports. “Last month it generated more than $80,000 in sales. At this rate the machine would pay for itself in one year.”
This system does its share of routine part processing, but it also handles a large flow of part remanufacturing. According to Johnson, three quarters of the company’s 3D laser business success is generated through other manufacturers’ mistakes.
This three-dimensional application involves first cutting holes in the top part (XY plane) and then performing an operation on the side of the part (Z plane).
Johnson states, “Our bread-and-butter 3D laser business is actually coming from re-engineering others’ problems, like the shut-down assembly line where they suddenly discover the parts they have are either not cut or formed exactly to spec, don’t fit properly, or are nonconforming. In scenarios like this, their choices are limited. They can scrap parts and spend hundreds of thousands to modify a die while the production line is idling, or have us pull them out of a jam with Domino. We’re also doing a lot of rapid prototyping applications where smaller quantities and speed is the name of the game. In fact, we are aggressively expanding our rapid prototyping program in 2005.”
Consider how this system allowed PMF to help solve an urgent problem faced by a tier one automotive supplier who learned that 6 x 6 mm square holes in vehicle doors scheduled for assembly were too small so that a new molding design could not be attached without modifying the size of the hole. Although they were able to modify their hard tooling for the longer term, they still faced an immediate problem. “The decision was either scrap 25,000 doors or quickly repair the preformed doors by laser cutting them. The solution was actually simple; the existing hole was enlarged to 6 x 20 mm to accommodate the new molding,” says Johnson. So in the coming days, trailer loads of doors arrived and left PMF’s plant until about six weeks later the project was complete.
The deformed edge of the top half of a prototype suspension system is removed so that the top and bottom of the part can be welded together.
So how did PMF initially discover the need for a 2D/3D laser? “My earliest recollection was when we realized the need to save time and cost to produce a beveled hole in a customer’s otherwise flat part,” says James Miller, manager of CAD/CAM and laser operations. “We didn’t want to add operations. If anything we wanted to eliminate cutting and countersinking, so we thought a 3D system might do the trick for work like this. We were also seeing an influx of preformed product such as tube, another good reason for 3D. However, we still needed to cut two-dimensional work faster than ever. We found the Prima system had a versatile, low-maintenance design and the speed to handle our heaviest workload.”
PMF knew the door repair job was the type of work that would be great for this laser. So it was not surprising for them to see more. Sure enough, fix-it work from a variety of companies became the norm, as more re-engineering applications kept finding their way to the fab shop.
Not long after the Domino was installed in early 2003, it successfully took on its first fix-it case with Electrolux, a regional manufacturer of lawnmowers. “They found themselves in a situation when they discovered the side grass chute of the decks they were forming failed to punch out,” notes Johnson. “The culprit was a faulty die, which isolated the problem, but not until after 300 decks were formed and the operation ground to a stop.” The solution was quick as the laser was able to cut out the side chute. “They were pleased when they learned they wouldn’t be scrapping 300 decks,” says Johnson, “so we got a nice order that kept production flowing, not to mention profit.”
Miller says other factors come into play as well, “Our production throughput, set up, and maintenance time savings are also very significant with this system, as well as consistent cutting accuracy. One of the best features is set up ease. Change-out time is virtually nil, especially due to the shuttle system. We can set up a table with a fixtured 3D part, run those parts as long as we want, and then change right into a 2D application with little or no effort.”
Domino, a flying-optics type system, can cut anything within a 120 x 60 x 16 inch working envelope from regular flat sheet to three-dimensional pieces at any head orientation. This is accomplished with an “A” axis that has 360-degree continuous motion and a “B” axis that has +/-135 degrees of motion. There is also an additional CNC rotary axis that can be used to cut tubular product.
Johnson illustrates how automated laser productivity paid off on another remanufacturing job, this one for Dixie-Narco, a Division of Maytag, where four holes were inadvertently left out of a vending machine part. PMF was given two days to process 500 parts. “The part was 4 x 4 x 39 inches, formed in an elongated “w” shape, having one plane with two 3/8-in. holes and another with two 3/16-in. holes. It would have been very difficult to set up, fixture, and conventionally machine, requiring a template and a fixture to hold it, then manual drill it, turn it over, rotate it by hand, and drill again etc. The whole process would have easily taken approximately five minutes per part and drills would have been subject to wear, and there is also the human error element,” explains Johnson.
“We simply downloaded their part layout to the laser, input the cutting conditions, type of material, and assist gases for cutting, speed of cut etc., pressed a button, and the machine did its magic. The entire operation took no more than a minute per part, including load and unload. So we dramatically simplified fixturing, eliminated drilling, two hand movements, and tool wear, and consistently got more accurate cuts as well,” says Johnson.
In summary, Johnson says, “It all boils down to speed and profitability. We can produce some parts up to eight times faster and realize significantly more savings by using Domino. We don’t wish mistakes on anyone, but it’s nice to know we can prevent scrap, solve problems, and please the customer, all while making a decent profit.”
Contributed by Prima North America Inc., www.prima-na.com