Millennium Patterns

Metal Casting Patterns Produced on a CNC Router
Costing One-Fourth the Normal Price

Millennium Patterns, Leeds, Alabama, produces wooden and plastic metal casting patterns on a CNC router that costs only one-fourth as much as those normally used for the task. When the pattern industry switched to CNC several years ago, most companies purchased small machining centers that cost in the area of $80,000 including programming software. Millennium Patterns, when it started operations one year ago, decided instead to purchase a lighter-duty CNC machine designed specially for wood and plastic machining. Co-owners Joel Busler and Jim Collins said that with less overhead than its competitors, the company was able to reach full capacity within a few months of opening its doors by providing its customers high quality patterns at a very attractive price.

Patterns are used in the foundry industry to produce sand molds that are used to cast the actual part. Patterns for parts that are produced in quantities of thousands require metal patterns that must be produced on machining centers. On the other hand, wood or plastic patterns are used for parts that are produced in smaller quantities because of their lower cost. Just a few years ago, these patterns were typically produced on lathes and bandsaws by highly skilled operators who often spent days or even weeks finishing each piece. The problems with this approach were 1) it was very labor-intensive, 2) accuracy depended on the skill of the worker and 3) a mistake made it necessary to scrap the piece and start over.

The advent of CNC machining changed this business in a major way. Pattern producers could now define their pattern to a very high level of accuracy on the computer and have it automatically cut to the precise geometry that they specified. The only problem was the cost of the machine tool. A working area of about 14 by 24 by 5 inches is normally considered to be the minimum required for pattern work. A machining center of this size would be ideally suited for a pattern company that produces metal patterns but has far more rigidity than is required for wood, plastics and lighter metals.

CNC routing methods have been a key to Millennium's success in the pattern business. The two owners of Millennium Patterns had each been in the pattern business for about 12 years when they decided to start the firm. Their primary concern in starting the business was the need to finance an expensive machining center that they felt they had to have to be competitive in the business. That's why they were pleasantly surprised, shortly before going off on their own, to discover a machine designed specially for lighter-duty machining at a much lower price.

The Techno Series III gantry router from Techno, Inc., New Hyde Park, New York is similar in function to a CNC machining center. At about $20,000 including software, the router is considerably less expensive than a machining center and designed for lighter-duty work. Yet, it provides the same surface finish and accuracy as a machining center. Its working area of 29.5 inches by 21 inches with a Z-axis height of 11 inches, is larger than nearly all machining centers in the under $100,000 price range. The machine can handle virtually any type of material although it is limited to relatively small depths of cut in ferrous and other tough-to-machine materials. In fact, one key feature is the Techno servo system's ability to cut 3D continuous contours at up to 200 inches per minute, far faster than most machining centers.

Millennium purchased the router and its owners were able to teach themselves to operate it in a day or so. This was largely because the Mastercam® CNC programming software, from CNC Software Inc., Tolland, Connecticut, supplied with the router, was easy to learn. Although originally designed for metal working, Mastercam® is also well-suited for industrial design models because of its ability to generate the most complex contours with little programming effort. Mastercam® includes IGES, DXF and CADL converters so that geometry can be uploaded from many CAD systems.

The router proved to be ideally suited to pattern making. When they first opened their doors, they didn't have any work and used the router to machine 12-foot long signs that helped draw attention to their business. As business started trickling in, they demonstrated that they could produce patterns to the same high level of quality that is achieved by more expensive machine tools. The Techno router's .0002 inch resolution and repeatability and 0.003 inch/ft. absolute accuracy are the result of several features inherent to the table, such as the use of ball screws and servomotors. For example, anti-backlash ball nuts permit play-free motion that makes it possible to produce accurate circles and inlays.

















Millennium showed that they were able to produce patterns at the same high level of quality as that attained by more expensive machines. Once they proved that they could match the quality of larger shops using more expensive machines, business really started to takeoff. The firm was able to offer lower prices than many of its competitors because it didn't have the burden of having to pay off an expensive machine. Another factor that helped keep costs down was the many years of programming and machining experience possessed by both of its owners. It was also often able to offer faster delivery times than the larger pattern shops. Within a few months, Millennium Patterns was operating at 100% capacity.

The majority of the company's business so far has come from the construction industry. (One customer is Allen-Robbins Architectural Metals, one of the nation's largest ornamental and historic restoration suppliers). For example, they have produced patterns for stairways, balconies and lamp posts. One of their most interesting projects was a 14-foot long fluted support for a hotel restoration project in Selma, Alabama. On this project, as in many others, the Millennium owners traveled to the site to take measurements and make a reproductive mold to insure the accuracy of their pattern. The ability to produce high-accuracy patterns at a reasonable cost has in several cases made it possible to produce one of a kind or very low volume castings that would not have been economical using earlier methods.

In approximately 3000 hours of operation, Millennium Pattern has had no problems with the Techno router. This is partly due to the strength and rigidity of the table, which is constructed from extruded aluminum profiles that provide easy clamping capability. The router also has four ground and hardened steel shafts and eight recirculating bearings in each axis. This rolling contact ensures longer life and greater rigidity during the life of the system because of the reduced wear as compared to ACME screws and nuts or rack and pinion systems, which have a sliding friction contact.

Millennium co-owners Busler and Collins say that the use of the cost-effective CNC router has been instrumental to their overnight success in the pattern business. "This machine has helped to make us the low-cost producer in the pattern business in this area while achieving the same or better quality as our largest competitors," Busler said.