Will RP Stand For Rapid Production Someday?

Spurring industry's interest in rapid production is the trend toward mass customization, where - at some point in the future - a production run could consist of just a single end-use part. Mass customization manufacturing allows manufacturers to realize all of the benefits RP has to offer. Using 3-D solid CAD tools, along with an RP system, the manufacturer can design and perfect the product by building various iterations to it. Then, once the design is perfected, the manufacturer can make customization changes to that same data file to rapid produce a customized part.

The ways in which rapid production has the potential for changing manufacturing's future is staggering. When rapid prototyping first hit the scene a decade ago, moldmakers were running the other way, not wanting anything to do with a process they feared would eliminate prototype tooling altogether. But a few brave moldmakers rode the RP wave all the way to the bank. And, as rapid production takes a firmer hold, customers will see the same thing.

Several companies already use RP driven processes to manufacture end-user products, but in low quantities. Rapid production parts can be found in the automotive, aerospace, consumer electronics and business machine industries. Additionally, jewelry, toys and medical and consumer products also are being made using rapid production methods.

As the rapid prototyping industry continues exploring ways to apply its technologies to rapid production applications, a number of changes face it in the form of new material properties, surface finishes and speed - changes rapid prototypers have only felt the tremors of so far.

"I don't see rapid prototyping itself disappearing anytime soon," says Eric Prewitt, sales manager for Michael Engineering, Inc. (Mt. Pleasant, MI) - a metering equipment company. "We have seen changes in our market, particularly in the last year when there was fantastic growth. However, while I don't see rapid prototyping giving way to rapid production, there has been some maturing as well as some inroads made by rapid production."

What Is Rapid Production?

Protoshapes' specialty is production of polyurethane plastic parts and molds to produce parts. The company says it can produce molds and parts at a fraction of the cost of conventional methods and in half the time using rapid production. Protoshapes discovered that the more cavities or molds it had, the more parts it could rapidly produce. The processes Protoshapes needed for doing rapid production work were already in place - spending little money and lots of time developing the tooling and process for its rapid production plans.

The company first operates a machine that dispenses tooling material over a pattern that has been embedded into clay for the parting line. They dispense tooling material with a metering machine, wait fifteen minutes, pull it out, clean it off and then shoot the other half of the tool. They pop the whole thing apart, remove the pattern, clean it out, implant screws in it and then stick it into an oven that post-cures it for an hour. At that point they can take another machine with a different plastic and start filling the cavities. From the time they start with the pattern to making a single part takes about an hour, says Rob Small, president and owner of Protoshapes. Even with a single-cavity tool, Small says he is able to make between 30 to 35 shots per day.

"For many companies struggling to meet production and development costs, polyurethane molds are the key to making projects feasible and more affordable. Tooling costs for polyurethane are a small fraction compared to hard tooling for thermoplastics. It takes only a few days - or sometimes hours - to build molds made from polyurethane to form many different types of plastic parts. Steel or epoxy molds can take up to a month to produce. We are currently targeting those companies that currently use polyester fiberglass to produce parts. These companies have thousands of small parts to manufacture, but we have the ability to manufacture these same parts in less time and for less money," Small explains.

The Next Frontier

"Six months ago we would have just been talking about stereolithography as a step toward rapid production," says Gordon Moore, VP of the Americas for 3D Systems, Inc. (Valencia, CA) - a rapid product company. "SLA systems do have the benefits of being accurate and fast, but the range of materials properties is limited. Among the technologies being used to support manufacturing are laser sintering and resin-based machines using high durability materials. As improvements continue with sintering, we will be able to move closer to SL accuracy while providing tool-less manufacturing - which is where one goes from the CAD drawing to the final output, with that final output useable with minimal finishing. As we continue developing other methods, we will be able to bring materials to the table that allow more options for directly producing either the tools or the end-use part."

Despite these advances, industry scribes expect that very few manufacturers will want to go from zero to 100 miles an hour when adopting rapid production practices. Since many companies look at rapid production as a "long trip," you will see more of a "step-by-step" approach adopted until companies get comfortable with the process. The reason is that much of manufacturing today is process-oriented, which means that any quick change toward rapid production puts production output in jeopardy. One of rapid production's beneficiaries has been the aviation industry. The tools used in aviation have long life cycles so that when they make a tool they have to keep it around for a long time. Using a digital model of a tool, companies can store it electronically and build on demand anywhere in the world for the life cycle of that product, says Moore.

"The aviation industry will be producing rapid tool-less parts in 2002," Moore explains. "The only thing limiting this expansion is how quickly the various regulatory agencies approve materials. You will see low-volume manufacturing grow next year. Rapid tooling will become standard in the next two years and the manufacturers that are not going in that direction will be severely limited in responding to market changes. Cost is always an important factor. The slumping economy is sure to spur on manufacturing companies doing low-volume products because they are not afraid to spend money if it increases productivity."

Rapid Production at Work

"I thought this would be a good opportunity to see how the polycarbonate material held up in a demanding application," says Kirk Moswen, the company's fabrication manager, whose use of Stratasys' Titan helped him rapidly produce a replacement pulley. "I had a CAD model of the pulley drawn up and we built it from polycarbonate. It took just a couple of hours to run the part. We then bolted the pulley on the belt sander and production was allowed to continue without much interruption."

Moswen says if they had been forced to wait for a new part, the production line would have been forced to shut down. Thanks to the rapid production, the pulley was still in use several weeks later.

"With the ability to now produce an end-use part rather than creating masters, the future is now one step closer - eliminating one stage of production and going right to fit, form and function the first time around," says Jon Cobb, vice president of Stratasys, Inc. (Eden Prairie, MN) - a RP/RT developer. "Allowing development of parts on demand, once it really catches on, will be an amazing thing for the manufacturing world."