MMS

"Mastercam Delivers Needed Speed for Faster Part Production."

S & S Cycle Company produces aftermarket engine products for Harley Davidson and custom motorcycles. Their products keep these bikes fast and reliable on the street and at the drag strip.

For the company’s parts and engines to offer high performance capabilities and stay ahead of the competition on the street and strip, S & S Cycle (Viola, WI) has to take advantage of advanced production technologies. One of these important technologies is state-of-the-art CAD/CAM software that allows them to develop unique racing parts “that they couldn’t produce without it,” said Barry Peterson, prototype R&D CNC machinist.

In the 1950s S & S Cycle founder, George Smith, had one goal: to make American motorcycles faster. His hobby was racing, and he had some ideas on how to make motorcycles quicker. At the time there were no high-performance aftermarket motorcycle parts. Therefore, Smith decided to design and manufacture his own unique performance parts for Harley Davidson engines. Through his racing and other contacts, word got out, and Smith found that there was a demand for his components. With this demand, he founded S&S Cycle in 1958. He worked out of his basement in Blue Island, IL for 10 years until he bought land near Viola, WI. He moved to this area in the late 1960s and hired a few people. Over the years the company has produced parts that include power kits, carburetor and fuel systems, transmissions, gaskets, seals, valves, heads, and even complete V-twin engines. S & S Cycle soon became the world’s most prestigious manufacturer of aftermarket performance motorcycle engines and parts with many of its engines being used for custom motorcycles.

Today, one of Smith’s sons, George Jr., is focusing his time on racing in the National Hot Rod Association with fellow racer, George Bryce. Their race team does on-track testing and competing with their V-twin motorcycle engines. “Our engines compete directly with the Japanese four cylinder engines, which has been a new challenge for the R&D team and George in particular,” added Peterson. “Designing and making parts for this V-Twin Pro-Stock 160 cu. in. engine is one of the main projects we’ve been working on recently. Our company’s philosophy has always been to sell what we race, and to prove out the performance and durability of our parts and engines.”

To squeeze every bit of horsepower from their engines and to manufacture race-proven parts, S & S Cycle relies on Mastercam (CNC Software, Inc. Tolland, CT) CAD/CAM Mill level 3 with Solids software. Mike Mattera of ShopWare, Inc. keeps S & S Cycle up-to-date on the most cutting-edge developments in Mastercam. This software has allowed the company to design more complex products and parts and machine them faster. In fact, Peterson remarked that some of its parts couldn’t be produced without the capabilities of Mastercam.

“Our V-twin engine is based on the Harley-Davidson design with many high performance improvements, and ones that give the engine greater durability,” said Peterson. “We are working towards taking the V-twin engine a step further by continuously making improvements to it.

“With our Mastercam software and five-axis machining centers, we can make greater enhancements to our engines. With Mastercam we design a part in Solid Modeler. Then we take the model and import it into Mastercam and produce a tool path. This allows us to start out with a block of billet aluminum instead of a casting and make just about any shape we need. By using solid billet material it saves us time with prototypes, because we can skip the casting mold. In some applications, billet parts may have a strength advantage over castings and many customers like the look of billet parts. Machining parts from billet material also has another advantage. We can easily make changes to the part design and produce them quickly, because there’s no need to wait for a mold change. This saves us time and allows us to market products faster.”

“We found Mastercam to be user friendly,” remarked Peterson. “It allows us to bring in a model from CAD software, and generate tool paths for everything from basic contouring, drilling, tapping, to complicated profiles, and intricate surfaces that are continually changing in surface finishes.”

For more complex features and surfacing, he said it has significantly reduced their programming time. “Where Mastercam is really making a difference is on very complex surfaces. Also, Mastercam has opened new doors for us. It has allowed us to make complicated parts with complex surfaces that weren’t practical or even possible for us to do before,” he added.

S & S Cycle’s V-twin engines are made with billet, cast, and forged parts. The bulk of our prototype parts are made from billet material to save on the time and cost of producing castings and forgings. S & S Cycle’s most complicated surfaces are found in their racing cylinder heads that contain the combustion chamber, valves, and ports. “Cylinder heads have been an interesting R&D project because of the ports for the air/fuel mixture and exhaust,” added Peterson. “Anybody who is familiar with high performance engines knows that the key to making a lot of horsepower is to have a really good cylinder head with ports that flow air and fuel very efficiently and produce a good burn pattern in the combustion chamber. This is something that we are always working on to improve.”

The billet Pro Stock heads start out as aluminum rectangular blocks that weigh 68 pounds. After machining, they weigh only 12.5 – 13.0 pounds. For racing, they try to eliminate as much extra weight as possible. But at the same time the heads have to be durable. Wall thickness between the outside of the head and the ports has to be constant. Ports also need the right surface finish that eliminates or reduces flow turbulence and allows the air/fuel mixture and exhaust to move quickly through them for more horsepower. Creative undercutting in the ports is what separates the NHRA champions from the average street racer. S&S Cycle roughs with a ¾” ball tip end mill and finishes with a “mini-master” ½” ball tip end mill. Then a handwork operation is done to smooth out the port’s walls. “These heads are more like a sculpture with a lot of unusual surfaces that have to be machined and blended together,” added Peterson. “Just roughing out a port could take 9,000 to 10,000 blocks of G-code, and finishing them takes even more code.

“Machining ports with a 5-axis Fadal has been something we’ve been able to do now that we have Mastercam. The software allows us to produce a tool path for a spiral cutting pattern in the ports and be able to duplicate it. Another thing we do is use our Fadal’s digitizing option. We use points from digitizing, import them into Mastercam, and then create surfaces. Next we produce a toolpath from the surfaces. We’ve been able to duplicate ports that were originally done by hand. We check their flow pattern, and if we like it, then we’ll duplicate the pattern so that we can machine it, making it much faster and more consistent than doing the ports by hand. Mastercam makes it much faster, and its fine-tool axis control allows machinists to reach the tricky spots in the port and still maintain tool clearance.”

S&S Cycle also relies on Mastercam’s ability to import and export different types of files. The engineers design 2D drawings and 3D surface models and then save the files in IGES or DWG format, which easily move into Mastercam. Also in 4- and 5-axis machining, it is important to machine the part from many sides. Peterson adds, “Mastercam makes it easy to machine at different A and B index positions. The toolpath is programmed at the proper plane, and the post processor puts it into the correct index positions in the G-code program.”

For S & S Cycle, looking for a CAD/CAM system started several years ago. “Everybody in racing is looking for an edge,” Peterson says. S&S Cycle was looking for CAM software to solve several problems. They needed to improve surface machining and cutting ports in heads, along with being able to do special parts without producing castings. The company knew they needed a CAM system to do this. Peterson said they attended IMTS and other shows to review the many different program packages available. They picked Mastercam because of several reasons: the software has been on the market and proven, upgrades are made to it based on customer input, it has a wide selection of finishing and roughing options, and CNC Software, Inc. is a well established company. “We wanted to make sure the software company would be around after a few years and not be out of business,” remarked Peterson. “Some of these companies you weren’t sure if they’d be around after a few years. You’d spend a lot of money for software, much time to learn it, and then they’d be gone, along with your support.”

Mastercam is used by the company for R&D work, but their part programmers are going to be using it for production components. “Our production group sees a lot of potential with Mastercam to help us make programming more efficient,” added Peterson. “They have purchased a license for a network of four seats. With Mastercam’s options, it makes it more efficient for programming production parts. The only thing we regret about Mastercam is that we didn’t get it sooner.”

S&S Cycle has an impressive success record, on and off the track. They were named Wisconsin Manufacturer of the Year in 1998, and they have been active participants in setting important motorcycle land-speed records. They contributed to the success of champions throughout the racing world.