Automatic molding puts AC Foundry on the productivity path.

The latest phase of a continuing upgrade has eliminated labor and productivity problems for this aluminum foundry.

"If you look at where we were four years ago, compared to where we are today, the difference would blow your mind!" exclaimed AC Foundry's Vice President, Mike Chenoweth. "We've put a lot of money into the foundry for capacity, quality and ergonomics improvements."

The last and most dramatic phase of those improvements was completed last August, with the installation of a new mold-handling system and a state-of-the-art automatic moldmaking machine. This $622,000 move has eliminated serious problems that had plagued the small aluminum shop in the last few years, and positioned it for a very bright future.

'Pushed Into a Corner'

Founded in 1962 in Battle Creek, Michigan, by Mike's grandfather, Arthur W. Chenoweth, AC Foundry, Inc., is a jobbing shop with 17 hourly employees. The firm, now led by Arthur's son Larry, has produced orders ranging in volume from one casting to 50,000 pieces. Of the 14,000 lb of aluminum it melts per day in six Thermtronix electric resistance furnaces, 67% is Al 319, along with Al 356 (23%) and Al 335 (10%). Cores are produced from a Dependable 100 and two Redford Carver 43-A shell core machines, as well as a Palmer continuous-mixing nobake unit. The foundry makes castings for hand tools, blowers, housings, pumps, valves, aftermarket automotive replacement parts and capital equipment.

Formerly, all AC's molding was done on jolt-squeeze machines. As recently as four years ago, Mike said, the foundry had workers "who could turn out 250-300 molds per day." That was soon to change, however, as skilled, experienced molders became harder to find. "Molding was once a trade with its own journeyman card," he said. "Nobody's out there training these people anymore. If we go to the trouble of training them, they take the skill and leave for better money." As a result, the foundry's productivity began to suffer.

To help alleviate the problem, a Hunter H&P 20 automatic molding machine was added in 1992, along with a mold-handling system. While three jolt squeeze machines were in operation, absenteeism was a problem at the union shop, and most of the time two molders a day were out. Thus, productivity continued to decline. "What could we do?" Mike shrugged. "You can't just take someone from the cleaning room and put him on molding - it takes a year to be trained as a molder. It got so bad that, while we had 13 people in our main molding area, the three jolt-squeeze machines were averaging only 369 molds a day. We were getting pushed into a corner."

AC Foundry also had concerns other than productivity. "Our work really begins at shake-out," Mike said, noting 30% of the firm's production costs are incurred in the cleaning room. The jolt-squeeze molds produced castings that required quite a bit of cleaning and finishing time beyond that for riser and gating cutoff. It was another problem that had to be addressed.

Reaching a Decision

AC's management finally decided it needed to take dramatic action if the foundry were to survive and profit in the long-term. The solution would lie in a total conversion of the jolt-squeeze operation to automatic molding. "About six months before the purchase, we sat down with the union and told them we have to do something, because things couldn't continue like this," Mike said. "There was no resistance from them - they saw the same problems we did."

The Chenoweths then went shopping. Among their criteria for an automatic flaskless molding machine was that it must be installed without pits, and that it be compatible with the firm's 800 existing patterns. The answers came in the form of a Roberts Sinto FBO II automatic flaskless molding machine. To complement the new unit, a brand-new mold-handling conveyor was designed by Metalcast Systems.

The FBO II (the first to be installed in the U.S.) uses top-blow mold filling and hydraulic squeeze compaction with variable force of up to 142 psi. It produces non-cored molds at the rate of 24 sec each - a maximum production rate of 150 molds per hr. For core setting, it features a system by which the drag mold automatically slides out toward the operator, allowing the core to be placed safely and easily. It also has a touchscreen control panel, and can be preprogrammed to implement changes in mold height, squeeze pressure and blow time.

The new mold-handling system was set up to receive molds from both the Roberts Sinto and the Hunter, with a mold from each machine on each car. The sequence begins when the Hunter discharges a mold onto a conveyor car. The car then moves down the line to the FBO, where the second mold is pushed out (without the use of bottom boards) to take its place on the car next to the other mold.

The car travels next to the pouring station, where two workers dip out of two separate furnaces. One pours the Hunter molds and the other pours the Roberts Sinto molds. The molds are then indexed onto a holding leg of the system, where they are cooled for 30 min. From there, they go to the Kinergy vibrating conveyor and onto the shake-out deck. Through all this, the molds are never touched by the workers.

With the introduction of the new machine, the jolt-squeeze operation was completely abandoned. "We got rid of all the squeezers," Mike said, "thinking that either we make a job work on the new equipment, or we get rid of it. We didn't want the temptation to go to the jolt-squeezer." Eliminating the jolt-squeezers inevitably eliminated the jobs of six temporary employees (who had posed most of the absentee problems to begin with).

Night and Day

"We're now putting out as many molds in one hour as one jolt-squeeze molder was in a day," Mike said. The two molding machines are set to each produce 120 molds per hr, and the foundry's capacity has been increased 250%. Man hours per mold decreased by 75%, and the molding workforce has been cut by half. "Jobs that used to take us weeks can now be done in days," Mike said.

Another benefit of the installation is illustrated by this anecdote from Mike: "One day, after the installation, both our main FBO operator and his alternate were out sick. In the old days, that would've crippled production. But we gave another worker 10 min. of instruction. He ran it all day without a problem!

"Comprehensive operator training on this unit takes about two hours. All he has to do is choose four options for the mold - cope height, drag height, squeeze pressure and blow cycle." Setting cores is a simple matter, since the drag slides out of the chamber to accept it. This easy-access feature squares well with AC's efforts to eliminate ergonomic problems for its workers.

"We pride ourselves on being a clean, safe shop," Mike said, "and a lot of the money we've put into the business in the last few years has been for ergonomics improvements. There are large foundries that do high-volume work on dozens of jolt-squeezers. But they also probably have a lot of workers' compensation suits on their hands."

On the clean side, the self-contained FBO completely eliminates spill sand and the associated airborne dust particles. The 120 GFN olivine sand is stored in a 100-ton silo (in place since 1994) and transported via conveyor directly to the molding machines. This stands in stark contrast to a video the Chenoweths keep that depicts the foundry four years ago - the sand stored in a huge pile on the floor where a Bobcat would pick it up and load it onto the conveyor, not to mention the usual sand dunes around each squeezer station.

Pattern conversion, one of the original concerns with the purchase, has turned out to be simple. More than 98% of the foundry's existing patterns can be easily converted to fit the FBO. "Sending patterns out for conversion can be an outrageous expense, and one that you don't really want to pass on to the customer. So we do them in-house for the most part," Mike said. "It takes less than 30 min for most of them. All we have to do is machine the holes and mount the pattern to a standard master frame. The only concern is that there are six different standard downsprue positions, so you just have to make sure you hit one of them."

There have been minor problems. "We've created some more scrap because we weren't experienced at tooling conversions," he admitted. Because the new machine fills the patterns from the side, there are cases where the mold arrangement must be rethought. For some jobs with deep pockets, cores have been added to compensate for the awkwardness of the filling angle. "We also have to do the occasional manual fill and tuck to compensate, but it's no real problem," Mike said. "You just have to be willing to take jobs and make them work."

Even on patterns that had to be converted or redone outside, the expense ends up being negligible. "So you have to pay to have it reconfigured," Mike shrugged. "In most cases, if you run the pattern once on this machine you've made your money back. Even if a job hurts you the first time around, you'll make it up next time." To further simplify matters, the FBO accepts wood and plastic tooling, lending more options. "With this machine, he noted, "the better the tooling, the better the casting. It has perfect draw, and if the pattern is warped, you'll offset the draw. That's the one drawback; human molders know how to compensate for a bad pattern."

Another major boon has been the reduction of finishing cost for parts run on the new machine. The most striking example is a health-care industry motor bracket casting that once required 100 hr per lot of cleaning/finishing time, and which now takes 40.

"We did have to convert this pattern outside from a six-on to a four-on configuration. That cost $2500, but cleaning room costs were cut by 50%. We're actually making the part for less than the customer specified - all we have to do is grind. In this case, we've been able to pass part of the savings on to the customer. This machine makes a consistent and repeatedly clean casting, with sharp parting lines and almost no flashing," Mike said. "Our overall finishing time on most parts run on this machine is down 30-50%."

Greater Flexibility

Like any major operational modification, the automatic molding installation has posed a serious challenge. According to Mike, "We don't have enough sand and metal to feed both molding machines." While the foundry's capacity has rocketed by 250%, it is now only running at 45% of that. A creative solution, however, is in the offing.

"Soon," Mike explained, "we're going to be able to go to two shifts, and alleviate the sand and metal crunch by only running one of the molding machines per shift. Each shift would be able to operate with only six or seven people, and we won't have to hire many - or expend any more capital. Running one machine a shift, we're still looking at a 30% productivity increase. As soon as we can get some more work in for the Hunter - which we're working about three weeks ahead on now - we should be able to do that. We're kind of holding back on the reigns right now."

The higher production allows more flexibility in pricing, as well as in operations. "I can now quote a heavily cored job at 75 molds an hr, and what used to take weeks is down to days," Mike said. "We're far more responsive to our existing customers, plus we can now compete with much bigger foundries for other markets.

"There are a lot of OEMs out there who use permanent mold for its high-production rate, though they could certainly live with sand casting quality," he observed. "We can go after those higher volume markets now." Yet the Chenoweths are proud that the switch to automatic molding hasn't hindered their ability to produce small jobs with short production runs. The 15-sec pattern change on the FBO provides the ability to mix smaller jobs of fewer than 40 or 50 pieces into the product mix.

AC Foundry is already looking at further improvements, including upgrades to the cleaning room and sand system, as well as an overall expansion of the plant facilities. This is made easier with the considerable return on investment for the new molding operation. "Based on a 15-year estimated machine life and excluding productivity improvements, we'll see a return on investment in 3.7 years," Mike estimated.

In the meantime, he reiterated the benefits both automatic molders and the mold-handling systems have brought to AC Foundry: "We've improved consistency, operational and labor efficiency, we can train a molder in hours and have dropped our cleaning room costs dramatically. This investment has opened up a lot of possibilities for us."

RELATED ARTICLE: A Proud Beginning

AC was not Arthur Chenoweth's first foundry. He had owned an aluminum shop in Coldwater, Michigan, in the 1950s, until that business had to be liquidated to pay off (a rather dubious) insurance claim. With that, he went back to work at other Michigan foundries.

But 1962 found Arthur unemployed for several months. One day, a customer from his old foundry showed up at his home holding three patterns, saying that he'd been unable to find anyone to match the quality of the castings Arthur had once made for him. He now wanted him to make them again. Ignoring Arthur's objections that he had no equipment or materials, the customer handed him a check for half the price of the order, gave him 30 days, and drove off.

"How am I going to make these castings?" Arthur asked his wife.

"You have your two hands," she said, "what more do you need?"

So arthur began making phone calls. A patternmaker he knew in Battle Creek had an unoccupied building, and agreed to let Arthur use it rent-free for six months. He then went to the site in Coldwater where his now-razed foundry had been. He went to where the sand silo had been, dug down a short way, and found about a washtub full of his old naturally bonded sand. He then took a 20-gal steel barrel, cut a few holes in it, rewired his wife's vacuum to make a blower, and loaded it up with all the charcoal he could fit (that furnace would melt 9 lb of aluminum a day). He nailed 2x4s together to make flasks, and made his molds.

When the customer returned on the appointed day, he wasn't surprised to find Arthur standing in front of his house with the entire order.

Thus began AC Foundry, Inc. Today, that first primitive charcoal furnace is chrome-plated, and sits proudly in the president's office.