WHOLE NEW BALL OF WAX

Fabricators today must find the most cost-effective and reliable method of operation. This applies especially to fabricating those small and medium-sized parts that require finishing operations or are composed of alloys that extend dependability and wear life – hence, a better finished product.

Investment casting is one technology that is ideal for making many parts with great accuracy, that offers the potential for substantial savings, but is often overlooked. Sometimes called "lost wax" casting, investment casting is a viable solution even for those who are making detailed or delicate parts in short or long runs – at amazing savings.

One of the advantages of investment casting that provides the greatest savings is your ability to avoid machine shop time. Air Ride Technologies (Jasper, IN), a manufacturer of high-performance automotive products such as air suspensions and roll cages, sometimes makes parts in low volumes when the products are first introduced to market. The firm prides itself on making high-quality, high-strength products with striking finishes that are appropriate for the performance market.

Although Air Ride has complete in-house machining facilities, there are occasions when investment casting is used to produce parts that require much detail and special finishes. This applies even to small parts that might be deemed mundane by other manufacturers. "We are using investment casting to make a bolt that is a tire cage clamp component and a bolt for roll cage assemblies," explains Andy Eckerle, Product Development Engineer. "The reason we chose investment casting was for the quality. We wanted a product that is intricate and has a quality finish. Investment casting allows us to make a part with intricate surfaces and yet make it cost effective."

Eckerle adds that while the textured, bead-blast finish of components matches that of the bar it supports – right from the casting – there are secondary finishing operations required; threading in this case. However, that is also provided by the investment casting foundry, Rimer Enterprises (Waterville, OH). Since 1944, Rimer has offered complete investment casting capabilities for items weighing less than an ounce to those weighing 75 lb, in quantities of one piece to one million.

Finishes that are close to flawless and near net shape are characteristic of quality investment casting. Through reduced machining time and effort it saves money. It also facilitates the design of parts with extraordinarily complex shapes, or combining parts that would otherwise have to be made separately.

K&M Newspaper Services (Monroe, NY), another Rimer customer, uses investment casting to make precision parts for its equipment used for inserting advertisements that are grouped together in one package and inserted into a section of a newspaper. "We historically have made a lot of mechanical components for these machines in-house from bar stock," says Andy Klopfenstein, Manager of R&D. "There are thousands of parts in a machine and they all have to function together in order for the equipment to function properly."

Klopfenstein says the investment-cast steel parts, which require considerable strength, require a lot less machining. "Some of the parts still require some final machining," he explains. "The investment casting will hold tolerances to about 0.005 in, but a lot of our parts get mounted to shafts and require a tolerance of 0.001 in be held on the diameter."

Klopfenstein adds that for any new equipment designs he always takes into account that with investment casting he can include some component features that he could not include if he had to machine them. "So, as part of my design process for investment cast parts I do that as much as possible – try to reduce the number of parts (in an assembly). In many cases these are non-standard shapes that would be very hard (or impossible) to machine out of bar stock," he says.

Outsourcing of parts can involve considerable lead-time, possibly months. This can be inconvenient, especially when volumes are difficult to determine. Working with an investment casting supplier online can shorten the lead-time, enable fine-tuning of part design, and enable a manufacturer to meet on-demand volumes more efficiently.

"We have developed several design changes with Rimer online," says Air Ride's Eckerle. "These were changes that enabled us to improve the design for the investment casting process and also improve on costs and turnaround time. With Rimer it's going to take 2-3 weeks to make a component. We get the quantity we need, including mass production if appropriate. We could not do that in-house."

Outsourcing offshore can involve even more time. Although many people might assume this would cut costs significantly, that is often not the case. In fact, sourcing parts through a domestic supplier can save time and money.

"Our orders usually don't exceed $2,000 to $3,000, so that doesn't justify outsourcing them from an overseas investment casting supplier," says Klopfenstein. "We have considered it, and have looked into pricing. The tooling might be a fair amount less, but the tooling for investment casting isn't that expensive anyway. So, when it came down to the cost of the piece part, there wasn't much savings over having Rimer make it right here in the U.S."

Eckerle says that Air Ride considers doing business with domestic suppliers to have significant advantages. "We were able to talk with Rimer for awhile, and could tell that they would be very good to work with," he explains. "They were not the cheapest supplier, but close enough to it. Plus, they are domestic. We try to stay 100 percent U.S. made. That gives us shorter lead times and assures us of quality. We are an American company at heart, and we know how important that is to our industry."

Air Ride Technologies, 350 S St. Charles St, Jasper, IN 47546, Phone: 812-481-4787, www.ridetech.com

K&M Newspaper Services, Inc., 45 Gilbert Street Ext., Monroe, NY 10950, Phone: 1-800-828-4202, www.kmnewspaper.com

Rimer Enterprises, Inc., 916 Rimer Drive (P.O. Box 27), Waterville, OH 43566, 419-878-8156, Fax: 419-878-6218, www.rimerinc.com.