The Dale Earnhardt Inc. (DEI) shop in Mooresville, North Carolina, is a resource center for NASCAR racing teams seeking faster, stronger, better performances, and parts that can endure the rigors of the track. “We pretty much support every team out there in one way or another,” said machinist Howard Elliott. “A lot of them have their own shops, but we still do some of our specialty parts for them.”
DEI opened more than two decades ago, making racing parts for its own team. Now, the business offers design and manufacturing services to all NASCAR teams, in addition to its developing own line of proprietary parts. Seeing the opportunity afforded by diversification, DEI started manufacturing parts for tractors, firearms, classic cars, and more to its roster of capabilities. Today, it is increasingly involved in dirt-track racing.
“Every customer is treated with equal respect,” said Elliot, adding that the company may specialize in “anything that can make a race car go around a track,” but that DEI’s “quick turnaround time and experience” are a benefit to all customers.
DEI machines in up to four axes and uses a range of machinery that includes seven milling and four turning centers, a wire EDM machine, and a waterjet cutting table. Parts are manufactured individually or in lots of up to 1,000, including smaller lots of highly custom parts and prototypes, and larger lots for parts that may fit into the palm of your hand.
DEI has used the Surfcam Traditional computer-aided-manufacturing (CAM) platform to program its machines since 2000, when it switched from another CAM system. “When the company was started, we needed a good design and CAM software to start making our own parts for the cars, and Surfcam ended up being the best choice for us.”
To design parts DEI uses the SolidWorks computer-aided-design (CAD) solution, by Dassault Systèmes. “Surfcam pairs well with SolidWorks, and going from a model to making toolpaths is very easy,” Elliott confirmed.
When it comes to making chips, DEI utilizes a flexible combination of machining strategies and cycles that enable it to achieve the maximum efficiency required to meet short lead times, while maintaining process quality. This includes the Z-rough cycle, a roughing cycle along the Z axis that removes large amounts of stock rapidly, preparing for subsequent material removal steps.
The Z-roughing cycle uses a two-axis (X,Y) pocketing cycle in Z-axis increments, an efficient method for removing material from around a part before the finish cutting. This option also can be used to remove large amounts of material from within a cavity.
Likewise, Z-finishing employs the same strategy for finishing operations, which work especially well on steep walls. The cycle engages the Z axis to follow a constant toolpath around the part profile to create an even, polished-looking finish.
Elliott and the DEI team also use Surfcam Traditional’s TRUEMill machining cycle, an optimized roughing toolpath that can be completed with a one-step, 3D roughing through pre-finishing operation. The toolpath creates uniform step height across all surfaces, regardless of how many tools are used, and removes material at significantly faster rates and greater depths of cut than more traditional cycles.
“When TRUEMill came out it really cut down on time for making parts, and made it easier on the machines and the tooling,” Elliott said.
Surfcam Traditional’s multi-cut option helps Elliott when it comes to machining complex, curved shapes, as its multi-cut three-axis toolpath makes it possible to machine single or multiple surfaces in a variety of cutting patterns.
The software’s “curve boundaries,” “check surfaces,” and “gouge avoidance” options — all functions that help to ensure the generation of ideal toolpath and surface finish — are supported by multi-cut, which is designed to deliver greater flexibility and overall efficiency. Multi-cut also helps programmers to understand how multiple toolpaths will behave once combined, and how the combination affects the final product, before the program hits the shop floor.
“For some of our three-axis operations, I use a lot of the multi-cut — especially if I have a lot of little radii or edges to put a radius on — because that makes it very easy,” Elliott said. “I’ve learned to use multi-cut for more than just multiple surfaces; where most people would use the cut option and cut the surface the way it is, I use multi-cut and I think it makes the part come out better.
“How I use it depends on the part that I’m working on,” he continued. “If I use the spiral option, it goes around and around and removes the witness line.”
DEI also takes advantage of Surfcam Traditional’s rest machining function, which is used to remove remaining material from hard-to-reach areas automatically. When roughing cycles are complete, material that’s impossible to reach with tooling used for roughing operations is typically left behind. The "rest machining," or "rest material," operation removes the “rest of the material” from the sides of contours and pockets.
“I rough a square or rectangle pocket with a large endmill and then come back with a smaller endmill,” Elliott said. “It knows what’s left from the big endmill, and you can tell it what kind of tool strategy needs to be used to get in there with the smaller mill.”
Because Surfcam Traditional is upgraded continually to reflect the changing needs of its users, DEI has been able to make consistent improvements to its programming processes. “Even programs I did last year, I usually wind up reprogramming because things have been upgraded — which allows me to upgrade the way I make them. As new versions of Surfcam Traditional came out, I was able to increase program speeds and feeds. I cut some two-hour cycle times down to an hour, and 15-minute cycle times down to seven minutes.”
The reliability of Surfcam support has been beneficial as DEI has experimented with new processes. “Over the years, I’ve always had good technical service if I ever had any problems,” Elliott said.