Thread Rolling Machines

Meet Walt Siegl, Custom Bike Builder

I later learned that Walt Siegl was a native of Austria who was attracted to both design and motorcycles from an early age. He held jobs as a toolmaker and welder in Europe then worked for a steel company in Russia before immigrating to New York City in 1985. He worked on motorcycles in Long Island City for years, mainly as a hobby, before relocating to New Hampshire to focus exclusively on building custom bikes. When I was at the Laconia Motorcycle Rally this year, I paid a visit to his workshop to learn more about the man and his incredible machines.

Walt Siegl Motorcycles is located in the ground floor of an 1860’s textile mill situated alongside a gently rolling stream. The space itself is beautiful and serene. Granite pillars frame a compact studio populated with the tools of his trade; vintage metal working tools, oxyacetylene torch and TIG welder. A bike in progress sat on a lift patiently awaiting its’ destiny while a handful of finished creations looked on.

Most custom bikes are predictably formulaic: S&S powertrains, long raked front forks, wide rear tires and garish paint jobs. These expensive creations are impractical at best and dangerous at worst. Walt has taken a unique path to custom bike building symbolized by his marque. His bikes are adorned with neither flames nor skulls, but a flower. Although the reference is decidedly tongue-in-cheek in an industry characterized by macho stereotypes, it offers insight into his worldview. He is trying to create something beautiful.

What makes these motorcycles unique is that they simultaneously occupy the space of both modern and classic motorcycles. Walt doesn't have a license to manufacture motorcycles so he starts with a street legal donor bike, usually a Ducati or Harley-Davidson . He’ll end up using a handful of parts from the original, but most importantly, he keeps the section of the frame and the engine case with the original VIN number. Although the bike may not resemble its’ former self when Walt is done, it can still be registered with the Department of Motor Vehicles.

The bikes are informed by the client’s wishes and to some extent, the donor bikes they are built upon, but each shares a common thread that is Walt himself. There are no computers. There are no CNC machines. It’s an organic process where custom parts are made by hand. The frames are chrome moly—TIG welded and heat stress relieved - and meticulously constructed around the engine. He uses models to perfect the proportions of fuel tanks and even paints the mock-ups to make sure everything is just right. And eye-catching custom details abound - fenders, oil tanks, seats, badges, risers, bars, dashes, upper trees, pipes. When aftermarket parts are employed, it's obvious they were carefully selected - think Öhlins suspensions and forged Carrozzeria wheels. The bikes are drop dead gorgeous, but what about what you can’t see?

Thread-rolling | Todays Machining World

We have always made single point threading to external threads on our CNC lathes, but lately, we received more requests for fillets rolled, especially by customers in the automotive and aerospace. I machine a wide range of materials including stainless steels. Threads can vary from about 1 / 4 "to 1", including metric sizes, up to 3 "long. I understand that rolled threads are mechanically stronger than cut son and I also heard the thread rolling process is much faster.I can not justify the cost of a stand-alone thread-rolling machine, preferring to give up parts of my complete machines to remain competitive in the automotive sector. What are the options for RSS-rolling on CNC lathes?

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