Manufacturing Engineering

TV American Chopper Shop Ramps Up

September 2006

American Chopper is a unique slice of Americana that lets cable TV viewers look over the shoulders of the designers and machinists at Orange County Choppers (OCC) as they conceive and build one-of-a-kind chopperstyle motorcycles and accessories.

The program is shot in a machining and fabrication reality environment complete with a big mustached boss who sometimes explodes when work lags behind schedule. OCC makes just about all parts using steel and aluminum, and operates advanced manufacturing equipment that any shop would be proud of.

	Tricky toolpath for the OCC Dagger Shield coil cover was designed in SolidWorks and streamed into Mastercam, and optimized for thin-wall (2.54-mm) CNC machining with surface finish for chroming.

OCC is very high tech. They rely on a Flow waterjet system capable of cutting through ceramic, glass, even a 12" (305-mm) block of steel, with minimal heat and no distortion of the material. They use a mandrel tube bender to create unique snaking exhaust systems without leaving any ripples in the metal. Advanced CNC lathes and mills turn and cut these exotic and beautiful parts.

OCC uses Mastercam CAD/CAM software from CNC Software Inc. (Tolland, CT) to program its five CNC machines. OCC seamlessly imports designs from SolidWorks, IGES, or other CAD files into the Mastercam CAM program, and translates them into programs for its Haas machines.

The point of one-off chopper building is to make an artistic statement, not flood the market with loads of look-alike bikes. So in 1999, when veteran machinist and biker Paul Teutul became serious about the business (moving it out of his basement), he thought production would probably max out at three choppers a year.

When the Discovery Channel caught up with him in 2001, production was somewhat higher because he had two people working with him. Later, as OCC bikes were seen by millions of TV viewers, the roof would blow off.

In the beginning, OCC used a lot of standard parts and components purchased from other manufacturers. Today, the entire bike is what lead engineer Jim Quinn calls an open canvas. In other words, most of what is visible on the bike is designed and manufactured by OCC.

In six frenetic years, Discovery Channel viewers have watched OCC grow from three employees to 60 (including the boss's two sons, Mike and Paul Jr.), and boost its production to 80 commissioned custom choppers in 2005.

	Dagger Shield coil cover is one of OCC's signature parts that will be produced for fans of the popular Discovery Channel program.

With millions of viewers following the exploits of American Chopper, OCC is poised to make some of the company's merchandise available to loyal fans who cannot afford custom choppers that range upwards from $40,000.

The first step will be a move into a new 100,000 ft2 (9290 m2) facility. This plant will allow OCC to ramp up production to the point where it can produce a small line of limited-edition bikes, and boost overall production to 120 bikes in 2006 and as many as 200 in 2007.

The old 30,000 ft.2 (2790 m2) plant will become the CNC production shop. Quinn said that OCC will have to streamline its manufacturing procedures to achieve output targets, and will use Mastercam to refine or redesign tooling and fixtures for increased productivity.

For example, an adjustable jig used to fabricate custom bike frames will be redesigned for production of limited-edition vehicles. The custom jig makes it possible to adjust the bike's rise and stretch to make each bike's dimensions proportional to the measurements and/or tastes of the person who will be riding it most often. It has been a great timesaver in building custom bikes.

The adjustable frame jig is an idea being worked on by OCC employee and frame welder Craig Chapman. Craig made initial sketches of the concept, which then were further designed and implemented in three dimensions using Mastercam.

"Once we are ready to make hundreds of bikes with the same rake and stretch specifications, we already have that jig designed in Mastercam," explains Quinn. "It will be quite easy to go back in and duplicate the dimensions we need, take out a lot of the adjustability, and generate the CNC programs to make our production jig." The same concept also holds for other tooling and fixtures that will need to be transitioned from a custom to a semiproduction manufacturing environment.

	Chopper production will be ramped up from 80 custom motorcycles in 2005 to 240 custom and semiproduction bikes by the end of 2007 in OCC's new 100,000 ft2 (9290 m2) shop.

Along with building limited-edition bikes, OCC intends to cherry-pick its custom part, accessory, and wheel designs to identify the ones that would be most appealing to fans. It will manufacture these signature parts on a production basis. The Nasty Wheel, the engraved OCC logo air cleaner cover, and the OCC Dagger Shield coil cover will be among the first made in production runs. The latter is the company's signature accessory, which they have used repeatedly on the custom bikes. The CNC machining process for the Dagger Shield has already been significantly streamlined.

The full 3-D Dagger Shield part consists of a highly detailed sword against the background of a rounded shield with rounded edges. The workpiece is precision-cut by waterjet from a standard 2.5 x 12 x 72" (63.5 mm x 305 mm x 1.8-m) aluminum billet, reducing the cost compared to using a custom-forged workpiece. Precise nesting of the part on the billet maximizes the number of parts that can be taken from a single billet, and minimizes the excess stock removal to only 0.030–0.040" (0.76–1-mm) around the outer edges of the shield. Quinn explains that to create enough space to hold wiring and other components within the cover, the walls had to be kept to about 0.100" (2.54 mm). This made workholding a challenge.

The part was designed in Solid-Works and imported into Mastercam. "Because the workpiece is already cut to near-net shape with only light cuts required around the perimeter of the shield, the part can be cut at higher speed with less tooling force for a faster production cycle and better surface finish," Quinn explains.

"I use the 3-D surfacing toolpath capability in Mastercam to get the detail of that dagger on the part, pulling a parallel plane, machining in two different directions first using an 1/8" (3.175-mm) ball mill and then a 1/16" (1.5875-mm) ball mill. The part comes out pretty near polished. The polishing that we have to do on it to get it ready for chroming is very minimal. Our chromer loves it. The dagger holds its detail standing up off that shield in chrome, and everything else is nice and smooth," Quinn says. The first couple of times this part was made on a prototype basis, the complete process took about six hours. Now, after tweaking the various steps, they have the time down to 1½ hr. The part is production-ready.