This article reviews engineering challenges in building a motorized surfboard. Bob Montgomery, a former professional surfer, founded a company named Powerski International in San Clemente, California, to help bring surfing to the masses. The motorized surfboard invented by Bob Montgomery includes a 330-cubic-centimeter engine, known as the SuperTorque XT, specially designed to fit within the hull's profile. Between the first design on paper and actual production, Powerski engineers made thousands of changes to the hull, engine, and other components. Montgomery found that designing a new engine had to be done within a computer-aided design (CAD) package to allow for the complexity of the parts. Although the hull of the Powerski Igniter 330 was designed by hand, engineers imported the physical prototype into the company's CAD system, which is from PTC. Montgomery expects jet boarding to become a popular water sport, akin to surfing. The jet board design puts the center of gravity under the rider's feet, rather than behind or in front of the rider. Controls under the bottom of the hull also put the pivot point directly under the rider's feet, for high-speed planing and turning, much like a surfboard.
When Bob Montgomery brought his motorized surfboard to market, he expected engineering challenges—but maybe not as many as he eventually met. He didn’t think, for example, that he’d have to become an expert in choosing and integrating engineering technologies or in engine design.
A look at the process he went through as he started a company from the ground up provides a glimpse of how engineering technologies can be the hidden driver in bringing a new product to market. Montgomery hired engineers, made decisions about purchasing engineering technologies, and implemented a just-in-time manufacturing system—not to mention the marketing of an entirely new product—successfully feeling his way through each step of the process.
Sixteen years ago, Montgomery, a former professional surfer and construction foreman, turned on his garage light in Capistrano Beach, Calif., and sat down to sketch the first rough design for an idea he’d been playing around with a while: a motorized surfboard he calls a jet board. He said his concept would bring surfing to the masses, no matter where they live, as long as it’s near a body of water, whether that body is ocean, lake, or river.
The Powerski Igniter 330 is newly available in the United States. Riders stand on it like a surfboard, and although it includes a mechanism for maneuvering, riders also steer it like a surfboard, by shifting their body weight. The Igniter 330 is now distributed in 35 countries. In August, it earned Coast Guard approval for U.S. distribution, Montgomery said.
Montgomery's 16-year journey from that initial rough draft to jet board production was by no means easy. Along the way he founded a company, Powerski International, in San Clemente, Calif., and hired an engineering team, led by Bjorn Levine, to design and patent a two-stroke, water-cooled, 45-horsepower engine that weighs about 40 pounds. The engine was specially designed to be light but powerful, to be compact with a sleek, side profile, and to perform well as it moves through water. Montgomery himself designed the jet-board hull, hollowing out the space beneath the rider’s feet to house the engine. He hand-made a number of prototype hulls from composite materials.
Can't Do It By Hand
Between the first design on paper and actual production, Powerski engineers made thousands of changes to the hull, engine, and other components. After he built an initial model of the hull in his garage, Montgomery needed an engine to motorize the surfboard.
“I wanted the engine to be low-profile,” he said. “Surfboards are flat. They don’t have big humps on them. There was no engine out there to fit that profile. I had to pull an engine off the shelf, an outboard engine, which I placed in the hole in the hull horizontally. It was ineffective. It wasn’t the correct design.”
He would have to do it himself. Montgomery hired Levine, who had designed motorcycle engines successfully in the past. He created a 330-cubic-centimeter engine, known as the SuperTorque XT, that fits nicely within the hull’s profile.
“I’d designed the hull and originally it had a sort of bowl in it,” Montgomery said. “I said to Bjorn, ‘I need you to make an engine to fit this bowl.’ And he did it.
“It had to be long, like a little torpedo engine, and narrow, because the board had to be narrow,” Montgomery said. “And it couldn’t be very high.
“There’s a host of design and engineering challenges when you design a surfboard and add an engine,” he said. “Water intrusion was one of them. When you sit on the board, it sinks. We had to make it not sink. We’ve come up with inflatable seals to equalize the pressure around the hatches. Then, the exhaust on the engine had to have one-way valves so water couldn’t get into the engine.”
Montgomery found that designing a new engine had to be done within a computer-aided design package to allow for the complexity of the parts. “At first, I thought I could do without a computer during the initial design phase and keep track of changes, but I couldn’t,” Montgomery said. To help in the design, he chose Pro/Engineer from PTC of Needham, Mass.
Powerski engineers now use the CAD package to design the engine, the hull, and everything associated with the jet board, including the steering handle.
While his business was in the start-up stage, Montgomery built about 30 different prototypes of the board by hand, shaping the molds himself.
“But as I sit here today, I don’t have a single blister on my hands,” he said. “Because now we’re designing the whole board in CAD.”
Powerski also uses a number of analysis modules, also from PTC, to test the product digitally before building a prototype. This enables engineers to work out the early kinks in their designs, said Steve Ryan, a production engineer at Powerski.
“We have an area on top of the board that’s for air intake, to get air to the carburetor,” Ryan said.
“We made a design change to this, and we wanted to find the volume of air that’s going through the area. We could analyze that, which is wonderful.
“We can do stuff like cabling and welding, and stress analysis if we need to,” he added.
The engineering team had to deal with five significant natural forces — weight, buoyancy, hydrodynamic lift, drag, and thrust—when designing the Igniter 330. The jet board combines a high ratio of thrust to weight with a hull design that stabilizes the craft at all speeds, Montgomery said. The board was designed to place the center of gravity directly underneath the rider, which also stabilizes the board. The design lets riders execute high-thrust turns by shifting their weight, he added.
When the jet board prototype was ready for water trials, Montgomery and his team placed sensors on the board and on the engine, to transmit data about water flow, hydrodynamics, ignition, and fuel injection. They transmitted the data to a Hewlett-Packard mobile workstation that they took with them to the beach, not even bothering to protect it from ocean spray. The workstation held up just fine.
Surfing Inside The Computer
Because Montgomery shaped the prototype boards by hand, the hull met his design specifications, but it wasn’t symmetrically perfect, which it needed to be.
It wasn't enough to simply measure the hull and pass the coordinates on to manufacturers. The geometry and specifications for the hull shape that Montgomery eventually approved had to be contained within the company’s CAD system, so engineers could tweak the part until it was symmetrical. They also had to have digital tooling specifications to pass on to parts suppliers, Ryan said.
Computer-aided manufacturing techniques need a coordinate measuring technique to achieve exact correspondence between the numerical model and the real component. Powerski engineers needed to produce a digital, numerical model from the hand-built hull.
For the reverse engineering of the hull, the team used scanning technology called Advanced Topometric Optical Sensor, from Capture 3D of Los Angeles. The digitizing system was run over the hull to measure it in high local resolution. Each single measurement generated up to 1.3 million data points, which were merged into a digital file of the complete hull. Engineers then shaped hull parts finely within the digital system.
Montgomery had taken his jet board concept beyond his garage in 1995, when he founded Powerski International. He soon found the company growing and the engineered parts morphing rapidly, as the design team tried to come up with the perfect jet board concept. Now he needed a way to track design changes and keep in touch with parts suppliers. In addition, his company was becoming a far-flung operation because he hired engineers located throughout the country. He figured, correctly, that they could work together via technology.
Shortly after implementing the CAD system, Montgomery and his team purchased a product data management system called Wind- chill, also from PTC.
“If there’s a change in our design here in the corporate office, we can distribute that through the Wind- chill Web site, and everyone gets updated immediately,” Ryan said.
Jonathan Boyce, the director of automotive operations at PTC, said that Windchill is intended to help track engineering change orders as well as to track products and parts. That feature is particularly useful at Powerski, which produces jet boards in more than one style.
“Powerski has a number of different configurations of its jet boards,” Boyce said. “But even color configurations have to be managed effectively in the data management system.”
The application is also used to store data so that it resides in one central location and engineers know how to get to it quickly.
Not only is the product data management system used to store information and track change orders, it also doubles as the Powerski collaboration system. Ryan said the system lets Powerski engineers around the company meet on the Web to review files, mark them up, and hold conferences about how the jet board is shaping up.
Water intrusion is one of the engineering challenges when you design a surf-board and add an engine.
Delivering In Time
Powerski is using a just-in-time method of production. When a distributor orders a certain number of jet boards, suppliers ship just enough parts to company headquarters to assemble that many, which are then shipped to the distributor. Jet boards won’t be stockpiled in a warehouse, tying up Powerski’s dollars in real estate and inventory. Because all manufacturing is outsourced, the collaboration software is used to coordinate suppliers, shipping dates, and distributor orders, Ryan said.
“We’re in production right now, and we’re shipping parts all over the world,” he said. “We have about 340 parts to coordinate with all the different vendors and with bidding and changes. Without that technology it would be a mess.”
The company also solicits proposals from suppliers via the Web site. “Instead of having to distribute requests to every single manufacturer for a bidding process, we’ve centralized it,” Ryan said.
And when an engineer tweaks a part’s geometry even as it is about to be produced, the engineering team can speed the new dimensions to the supplier via the Web site so the manufacturer can update tooling.
Montgomery’s team made well over 400 machine-tool changes while it worked on engine design. Before the company implemented the collaboration technology, it sent all those changes to suppliers via fax, e-mail, phone, or conventional mail.
“As we started up, we saw that this was the wrong way to do it,” Montgomery said. “If there’s a problem with our test units, we want to make the updates as quickly as possible, otherwise it’s going to cost us money.”
Ready For A Jet Board
All systems are go for the eight-year-old company as it adds more distributors. Montgomery expects jet boarding to become a popular water sport, akin to surfing. The jet board design puts the center of gravity under the rider’s feet, rather than behind or in front of the rider. Controls under the bottom of the hull also put the pivot point directly under the rider’s feet, for high-speed planing and turning, much like a surfboard. Because the board is motorized, a rider can plane and turn on still water.
“Not everyone can be like the Beach Boys and have an ocean in their backyard,” Montgomery said.
And he’s not shy about touting his product or boasting about the amount of work that went into its design.
“This is a birth of a whole new water sport that will change the direction of the watercraft industry the way the snowboard changed skiing,” he said.
Whether that’s true or not remains to be seen. But the amount of work behind the engineered product certainly deserves recognition.