Making One-of-a-Kind Seem Simple

May 13, 2021
A custom motorcycle designer and builder relies on advanced machining technology and an easy-to-use CNC system.

Fred and Len Kodlin have motorcycles in their blood. Master blacksmith Fred Kodlin gave his son Len his first motocross bike for his fifth birthday, and there was never any question about what Len would do when he grew up. Today, father and son operate the Fred Kodlin Motorcycle workshop in Borken, Germany, a custom-builder founded by Fred Kodlin in 1984.

Together, father, son and 10 employees customize Harley-Davidson motorcycles at a rate of up to 50 each year. Many customers simply want to have their series-produced bikes adjusted to suit them better, or to make a more individualized display. Other customers come looking for more specific modifications, such installing a larger front wheel, a very striking effect that is popular among Harley devotees.

The most passionate bikers, however, want their rides completely personalized. “These unique bikes cannot be beaten in terms of exclusivity. When it comes to design and technology, we make the virtually impossible, possible,” explained junior manager Len Kodlin.

In some of the Kodlin’s works the only thing left from the original is the engine, with that unmistakable Harley-Davidson sound: the rest of the bike is made up of components that have been developed and produced entirely by Kodlin. Customers’ budgets are the only thing limiting their imagination. (There are technical approval restrictions, too …TÜV, for example.) Enthusiasts pay up to $130,000 for these unique cycles.

Avoiding imitations -- When creating a someone’s idealized motorcycle, the customizers at Kodlin Motorcycle not only adapt parts but they manufacture many individual piece too. Various styles of footboards, footpegs, turn-signal trim, air filters, engine covers, hand grips, and mirror brackets are manufactured individually or in very small series. Outsourcing production could be cheaper in many cases, but for Kodlin, this is not an option.

Len Kodlin explained the reason: “Unique pieces are the basis of our whole company. The risk of copies appearing is simply too great. Our customers pay for something unique and that’s what we give them. This is why we do everything ourselves, from sheet-metal work and welding to milling, turning, painting, and assembly,” Kodlin said.

Kodlin has an extremely wide range of manufacturing capabilities to prevent imitations, safeguarding its competitive edge. The company invests heavily in production expertise and machinery. Kodlin even has a world manufacturer identifier. This official designation signals that Kodlin is officially a manufacturer that can build and approve motorcycles.

Integrated design to machine -- Anyone who wants to survive as a small, independent customizer needs top-quality CNC machines, and the core of Kodlin’s production process is a PreMill VL 1000 CNC machining center from MMD Werkzeugmaschinen, with Siemens' Sinumerik 828D CNC system.

Len Kodlin, a trained precision mechanic, explained what matters to him and his father: “MMD was extremely cooperative and, with the PreMill VL 1000, gave us a machine that meets our needs perfectly. The price/performance ratio was good and with the Sinumerik 828D control—including the intuitive Sinumerik Operate graphical user interface—our core requirement, namely ease-of-operation, was met to our utmost satisfaction.”

The demands on the machine tool and control system are high and diverse. Many simple parts are programmed directly on the machine. For this type of application, it is important for the shopfloor programming to be as simple as it is reliable and efficient. Jan Rosenkranz, a mechanic on the Kodlin team, came straight to the point: “The ShopMill menu-based navigation makes everything really quick and easy.” He also appreciates the convenient setup functions.

Producing custom parts, which often involves extremely complex contouring, is entirely different. The junior manager creates programs for these parts separately, at an external CAD/CAM workstation, and then transfers them to the machine, using a USB stick. This means the machine can remain in operation while the junior manager can design parts for his spectacular creations, far away from production noise. Once the blank is in place, the machining process goes very quickly. With the help of various Sinumerik CNC cycles, the workpiece and the tool are set-up quickly and machining can begin on the PreMill VL 1000.

Len Kodlin specifically mentioned the clearly organized folder structure in Sinumerik Operate, which is designed in a similar way similar to what is found on a traditional PC. Meaningful names—such as “Handlebar1-Customer3”—with up to 28 characters can be assigned to the programs. This improves the ability to maintain an overview and products that have been made before can be identified clearly and accessed again later.

Covering the spectrum -- In terms of production technology, the PreMill VL 1000 offers everything needed for bike parts. The machine gets extra points for its framework construction, which makes it very stable and easily accessible.

Most of the components Kodlin machines are less than 500 mm long. However, there are exceptions, such as long fork tubes. With travel paths of X = 1020 mm, Y = 510 mm, and Z = 560 mm, plus a 1200x500-mm clamping table, the machine covers the spectrum.

The 10-kW milling spindle provides the power needed to machine the aluminum or steel parts quickly and precisely. The changer can be equipped with up to 30 tools and the linear guides on all three axes ensure utmost precision. According to Jens Bubenheim, a sales consultant at MMD, the PreMill VL 1000 achieves a repeat accuracy of ±3 µm and a positioning accuracy of ±5 µm, which means that the desired quality is always guaranteed.

A special feature on the Sinumerik 828D CNC scores additional points for high quality, namely the Sinumerik MDynamics technology package with integrated Advanced Surface motion control. The program sequence can be set or adjusted at any time, ensuring that the machine generates an optimal ratio of speed, accuracy, and surface quality. For example, the turn signal trim: In this case, production accuracy is of less significance. Corresponding settings in MDynamics and the activated Advanced Surface therefore ensure that the machine works with a focus on both surface quality and speed of production.