Digging deeper into automation, robotics.

Inside This Story

* The benefits of implementing automation and robotics into a metalcasting facility are obvious. But deciding if automation is cost-feasible is not as clear.

* A close examination of the entire metalcasting operation is needed to determine if robotics can help your facility achieve the desired benefits.

Deciding when and where to automate a metalcasting facility is not always cut-and-dry. Implementing robotic's is not for every firm. This is especially true for small-to medium-size shops. Many operations possess the characteristics of an "automation-friendly" plant while others have to retool to get there. And still others may never find the light fit for automation.

To decide which category your firm is in, a detailed assessment of your entire operation must be performed because the decision to automate runs much deeper than simply component volume.

This article looks at three areas of a metalcasting facility that lend themselves to automation and examines what factors go into determining if automation is the right choice.

What to Look For

While the factors justifying the need for automation are specific to each area of a metalcasting facility, there are some general questions to consider, all relating to one thing--payback. Most metalcasters will think in terms of volume first as the quickest way to achieve payback. But it does not have to come from volume alone.

In lieu of high volumes, repeatability can be sufficient. If an operation id producing several components with similar characteristics, the robot may not require additional end of arm tooling (EOAT), resulting in cost savings.

Cost savings also can be achieved by automating a task that is labor-intensive and requires a lot of man hours. If robotics will improve consistency, and thereby improve quality by reducing scrap, further cost savings can be realized.

"Take a look at what the requirements are to produce that part," suggests David Reich, Laempe+Reich Corp. "What is the production requirement? What are the manpower requirements? What does the existing tooling look like? What is the floor space available to work within? Does the company have the capabilities to support it, and is it committed to supporting it from a maintenance standpoint? Are you generating high scrap in the process? Are labor costs high? Are you looking at new work that lends itself to robotics?"

Beyond that, Ben Sagan, vice president, Kuka Robotics, believes that metalcasters have to go in with a clear idea of what they want and where they are heading. For some firms, this may require a total shift in philosophy.

"From our standpoint, we approach this a little differently," he said. "What is your business modal? What is it that you as a manufacturer are trying to do? Are you trying to be a low cost provider? Are you trying to have a niche? Based on that, we can go in different directions."

Those different directions can take a metalcasting facility down the path to cost savings, time savings or quality improvement. But regardless of the direction, it has to have the same starting point.

"Often times, in the U.S., people don't like to start over With something, we like to patch," Sagan said. "I can't help you if you don't look at your whole process and view' the whole operation as to what is your overall objective, if you want to save a hit of cost and throw a machine over there, you are doing a stop-gap measure that will help you for 3-5 years, but you won't be around after that if you are just patching. Our company is not here to help you patch. There has to be a plan."

All of these things have to be considered. And they have to be further assessed in each specific area of a metalcasting facility to form a plan.

Cleaning & Finishing

Because the cleaning and finishing of cast components often requires consistently precise work and is labor intensive, it is an obvious place for metalcasting facilities to automate. If your facility is generating a lot of scrap as a result of inconsistent cleaning and finishing, it may signify that automation is the right decision.

"Quality improvements, especially in finishing, can be big," said John Kuhn, foundry automation specialist, Rimrock Corp. "If you go to an automated process, you have at least a 1% scrap improvement--and that's a minimum. People can't always process things properly. And that goes all the way through your whole bottom line."

Along with consistency, the amount of manpower involved in the cleaning and finishing of a particular component can he a major factor. Heavier, low volume components may help a metalcasting facility achieve the needed payback.

"We look at the labor hours and compare it to what we think we could do with a robot," said Christopher Cooper, vice president, Vulcan Engineering Co. "A lot of times, you have to look where your manpower is. If you have eight or nine guys working on the same part all of the time that is a good indicator."

Other times, the indicators are not as apparent.

"People aren't always able to maintain the level of quality throughout the day," said Jim Logan, metalcasting program manager, FANUC Robotics. "If you have a heavy pan that needs to be lifted with a heavy tool, and you have to work to remove the gate, there is an operation that might lend itself to automation. Operators may become fatigued halfway through the day and start leaving more metal behind as the day goes on. Then, your only choices are to put twice as many people on the job because of the heavy lifting or rotate operators every hour."

But while cleaning and finishing lends itself to automation, other aspects of the process can make it difficult.

"Cleaning is sometimes the most difficult application for firms to automate because manual operators often compensate for process variables," Logan said. "In a manual operation, you have the hand eye coordination of the operator to make up for parts coming down the conveyor haphazardly. It is not easy to automate a cleaning process when you have all of these variables. If that's the case, you have to ask, 'Can we fixture the part and have it come to a repeatable location for the robot? You have to be able to locate the components somehow so the robot can find them with the least amount of extra automation required."

Pacific Steel Casting Co., Berkeley, Calif., noticed a bottleneck forming in its cleaning and finishing department. The labor and individual attention that each suspension component for a heavy duty truck required was turning the area into a restrictor of casting production and shipment, turning dollars into inventory. The decision was then made to in stall a robot that has a six-axis manipulator and is equipped with a cutoff saw, compliant cup grinder and hydraulic trim press.

Under Pacific's traditional process of cleaning and finishing, four operators were needed to complete the task. After automation, cost for the suspension component being produced dropped from $5.64 to $2.64. Advantages also were seen in improvements in quality and consistency of the processed casting. There also was a higher throughput per square foot of cleaning room area, which opened up the space for other work and reduced leadtime.

Core & Mold Making

In core and mold making, it is important to look beyond the initial production process, while robotics provide a more efficient way of assembling cores and molds, their true need may be determined by what happens after assembly.

"Do I have to wind the casting and do a modularity rest to it and place it into a certain type of bin?" Reich said, "Do I have to definn it and wash it? Do I have to assemble it and then wash it? You start adding all of these things together and then ask how flexible it will be once you put all of that together. Flexibility and affordability don't always walk hand in hand. The metalcasting facility can be flexible, but it's how flexible the robotic cell can be with out exorbitant costs. You might be able to put in a robot cell, but then there may be high tooling costs. There will be so many grippers you wont be able to afford it."

The solution, Reich says, is to look for commonality and repeatability in the components.

"One of the big hurdles is the cost of the EOAT or a gripper," he said. "Those can be quite simple or quite elaborate. If you have to produce one for every single job, it becomes your single largest investment. By having commonality in your parts, you start having the possibility of the tooling required for automation. That also can transfer over to processing. Once you have the core, some of the necessary equipments for processing cores, definning, assembly and fixtures can use common fixturing. Often, it is a matter of having the possibility of having the same gripper location on parts."

Beyond that, the size and durability of the component must be examined.

"Sand core extraction handling is an excellent robot application," Logan said. "But you have to look at how you are going to handle it. Some are small and fragile. If they are too small and fragile, it may be a problem trying to handle them with a mechanical gripper. If they are going to have to be washed, the gripping fingers are going to cover up an area that may need to be washed. The robot is not going to be able to roll it and get everything evenly to make sure all of the areas are washed."

Indianapolis Casting Corp., (ICC) Indianapolis, is no stranger to automation. ICC has been automating its iron casting core and mold production line for 20 years. But increased competition sent the firm looking for ways to further reduce costs and maintain production levels. ICC installed a robotic cell fitted with 11 robot arms and gantries designed to produce, assemble and refractory coat the V8 cylinder package it was producing.

In full production, the robots assemble a V8 core package from a 12-piece coldbox core package every 45 sec. (more than 1,500 packages/day). In addition, the cell was designed to handle V6 and V4 blocks through quick tool changes of less than 10 min.

Pouring

Worker safety is probably more important in pouring than in any other process in a metalcasting facility. By keeping employees out of the equation, huge benefits in safety and cost savings can be realized.

When analyzing pouring, start by looking at the number of accidents that occur. Ergonomics are a big issue that could lead to injuries. And the obvious hazards associated with handling molten metal also should be addressed. By keeping workers away from the ladle, a metalcasting facility is cutting its risk of injury. Also, cost savings can be realized because less personal protective equipment (PPE) will be needed. It may not seem like much at first, but full PPE for several employees can add up over time.

Consistency also comes into play. if your facility is experiencing problems from an uncontrolled pour, that could be a good indicator for the move to robotics.

"Efforts to eliminate surface contaminants during the pour are easier with robotics," Logan said. "You are going to get more consistency in your pouring. For diecasters, that is one of their biggest issues when selecting automation for ladling. Another issue, depending on the kind of pouring process, might be the smoothness of the pour."

Melting and pouring by hand at TPi Arcade, Arcade, N.Y., was a difficult job that required two people per shill Scrap rates were high at the shop, which specializes in V-process aluminum casting. But the implementation of a robotic pouring system with a bottom-pour ladle helped reduce melt labor costs by 50% and scrap by 30%.

The bottom-pour ladle, integrated with an industrial robot, successfully completed the automation and helped the firm achieve a cost savings within a year. One of the biggest benefits was that operators were no longer exposed to molten metal. The firm's employees have not experienced a single injury in the melt shop since the robot was implemented. In addition, the number of employees needed to operate the melt shop has been reduced from three per shift to just one.

The Final Decision

The benefits of implementing robotics or automation into a metalcasting facility are far reaching. Nearly every aspect of the metalcasting process can be improved through automation. However, it takes the right operation with the right circumstances to achieve those benefits. For some firms, it may never be a possibility. Other firms may think it will never be a possibility. This can be determined only after detailed evaluations of the entire operation. There are no plain and simple guidelines to follow. Metalcasting facilities must first determine their limitations and expectations and decide if robotics and automation are right lot their operation.

"As long as there is some sort of sizable production ran, it makes sense to automate," Logan said. "But it is going to be up to each company to determine where their break-even point is." MC

For More Information

"ICC's Robotics Revolutionize Coremaking," A.T. Spada, MODERN CASTING, January 2002, p, 19-22.

"Opening Up to Robotic Change," R. Anaparti, MODERN CASTING, January 2004, p. 40 42.