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West-coast inventor Bob Montgomery first learned the way of the
waves in the 1960s riding Southern California beachbreaks as a
teenaged protege of surfing legend Duke Kahanamoku. Like many other
surfers, Montgomery imagined a dream machine-a one-man hydrokinetic
rocketship that would combine the freedom of surfing with a water
ski's ease-of-use and maneuverability. "I wanted to ride a
high-performance, motorized surfboard," recalls the 50-year-old
ex-pro surfer.
Now, due to his own determination and the availability of the
latest materials and CAD tools, he is about to see his dream come
true. It has taken the form of the Igniter 2000 TM
model Powerskitm Jetboard TM , a new
product from Powerski International, Inc. (PSI), a company he
founded in the garage of his San Clemente, CA home. Montgomery is
currently building a hundred prototypes for testing this summer, and
production models should go on sale later this year.
He says he has three U.S. and 27 foreign patents, with 61 more
pending worldwide, for this water craft that allows the rider to
stand rather than sit, as is the case with most competitive
products-and it's making quite a splash in the popular press. For
example, the Igniter 2000 and its proprietary engine won the Popular
Mechanics Design and Engineering Award for the new Millennium. It's
also been featured in magazines such as Popular Science, Watercraft
World, and Boating World. Among the Igniter 2000's engineering
innovations:
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A proprietary two-stroke, water-cooled engine that puts out
between 30 and 50 hp, depending on displacement. The 6.5-inch
thick, 50-cc engine weighs about 40 lbs, but use of a metal matrix
composite material should drop the weight to about 28 lbs,
Montgomery says.
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An axial-flow jet pump that delivers 350 lbs of thrust through
a proprietary gear-reduction transmission. The gear reduction,
built into the bottom end of the engine, is new to the power
watercraft industry. It enables engineers to match the engine's
optimum rpm to that of the jet pump to enhance the craft's
performance.
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Dual "hydrosteps" on the bottom of the hull that put the pivot
point directly under the rider's feet, enabling high-speed planing
and turning. They lift the craft partly out of the water as it
skims along, and direct the line of water rushing past the rails
during top-speed turns, stabilizing the craft.
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A four-ft-long "armpole" consisting of steel cable and a
sleeved wire harness covered by injection-molded rubber. The rider
holds the grip on the end of the armpole that has start and stop
buttons, left and right thumb throttles, speedometer and fuel
gauges, and a safety kill switch.
Design of the Igniter 2000, which has been a ten-year project,
required overcoming several engineering challenges. Dealing with
five significant natural forces: weight, buoyancy, hydrodynamic lift
and drag, and thrust, Montgomery combined a high thrust-to-weight
ratio with a hull/rail design and center of gravity placement that
stabilizes the craft at all speeds. The design also enables
high-speed planing and high-thrust G-force turns with simple shifts
in weight of a rear-mounted rider.
But the real key was packaging the jet drive system inside the
hull under the rider's feet. AutoCAD, from Autodesk (San Raphael,
CA) and Pro/ENGINEER from Parametric Technology Corp. (Waltham, MA)
were critical tools in the design process.
 |
| Key to the low-profile engine was laying
the cylinder down with respect to the crankcase and moving the
intake and exhaust ports to opposite sides, which required
rotating the piston 90
degrees. |
Sitdown & heavy. As a pioneer in the
industry, Montgomery saw changes in the personal watercraft (PWC)
design. As a standup watercraft, he says, the typical Jet Ski had
proved relatively unstable-riders found it difficult to maintain a
standing position because of the craft's forward center of gravity.
Kawasaki's solution to the problem was to go from "standup" to
"sitdown." The Jet Ski became a heavy, sitdown, square-railed
directional jet-drive watercraft. The move by Kawasaki and other
major industry manufacturers toward a heavy sitdown craft built up
Montgomery's confidence in his plan for a much more hydrodynamic,
standup watercraft. Where they went sitdown, he would go standup.
Where they went heavy, he would go light.
"They lost the personal'from the personal water craft when they
went sitdown," he asserts. "The new machines were heavy, bulky,
almost boats." So, Montgomery left the Jet Ski industry and set out
to help pioneer the "jetboard" industry.
The first actual jetboard/motorized surfboard appeared in the
1960s. The "Bloomingdale Jetboard," a handle-less standup craft
designed by Renard Storey, featured a low-powered (3-5 hp), 10-lb,
80cc engine capable of moving the craft at a speed of no more than
3-5 mph. Storey had designed his jetboard for surfers so they could
eliminate paddling, according to Montgomery, who had heard about the
original jetboard for years before finally getting a look at one in
the early 1980s. When finally he saw the Bloomingdale board, he
says, he knew why surfers
hadn't taken to the low-powered craft.
"It was built with a putt-putt' mentality," he recalls. "No
thrust, so no turns." For Montgomery, the limitations of the
Bloomingdale board only confirmed for him the efficacy of his own
design, which had taken shape years before he finally saw Storey's
design. In the years before ever assembling material for building
his first jetboard prototype, he mentally "pre-engineered" his
version of the standup PWC: a high-performance "power ski" board
long, narrow, buoyant, lightweight, low-profile, and
waterproof-propelled by a compact, powerful, jet drive system.
Montgomery continued to refine his ideas, and in 1981, he joined
Surf-Jet Corp., Janesville, WI, the one manufacturer that shared his
belief in the standup PWC. As new product manager for the company's
power-operated standup craft, he designed the production hulls for
the Surf-Jet Models 236 and 275, earning a place on the patent
records for his efforts. Then, as the company's west coast marketing
and sales manager, he began marketing the Surf-Jets. His extensive
knowledge of design, engineering and manufacturing helped make the
Surf-Jet a force in the PWC market in the 1980s.
But the Surf-Jet, as Montgomery saw while with the company, left
plenty of room for the sort of hydrodynamic PWC he was designing and
building. The position of the Surf-Jet's large engine-deadweight on
the tail-placed the craft's center of gravity behind the rider,
which cut down maneuverability. The standup Jet Ski's instability
problems had stemmed from the placement of the craft's center of
gravity in front of the rider.
Montgomery offered Surf-Jet his ideas for what would eventually
become the Powerski Jetboard-with the center of gravity beneath the
rider's feet, the rider's weight would dominate the craft to provide
complete steering control. But, he says, Surf-Jet wasn't interested,
and Montgomery moved on. In 1987, the entrepreneur in Montgomery set
out to meet the challenge of pulling off a major marketing success
without the benefit of initially having any money to pay for it. He
started in his garage, hand-crafting his dream machine.
In 1990, to formally raise the funds necessary for taking the
craft to the working prototype, pre-production stage, he formed the
HydroForce Group General Partnership. During the next few years that
the jetboard took shape, Montgomery struggled to keep focused on his
mission, even working other jobs to pay the bills as he labored in
his off hours. All the while he operated a "stealth" research and
development campaign, strategically keeping the prototype hidden
from the public (and competitors) as he slowly secured patents,
trademarks and other intellectual property rights protections.
His work was not without conflicts, however. On one occasion he
had to resort to fisticuffs to thwart a group of would-be thieves
intent on stealing his design. Once the Powerski Jetboard was fully
protected, Montgomery revealed his prototype to the world, securing
product placement stories for the craft in national magazines. A
card-carrying member of the Screen Actors Guild, he has also acted
in and performed stunts for numerous TV productions and in two
Hollywood motion pictures, including Kevin Costner's 1994 flick
"Waterworld."
In 1995, Montgomery co-founded PSI and moved to production
facilities in Brea, CA, where he finished design of the Igniter
2000.
Designing the dream. The most significant
challenge facing Montgomery in bringing his jetboard idea into
reality was the engine. "I needed an engine with the
horsepower-to-weight ratio that would give the consumer the ultimate
jetboarding experience," he says. After an extensive worldwide
search failed to turn up a suitable prototype, he says, he decided
to build his own. Hiring Bjorn Elvin as PSI's engine project
manager, Montgomery put Elvin's small-engine experience-gained while
working at Husqvarna's motorcycle and chainsaw division-to work. Key
to the low-profile engine was laying the cylinder down with respect
to the crankcase and moving the intake and exhaust ports to opposite
sides, which required rotating the piston 90deg.
Montgomery and Elvin developed the first engine, designing it
using AutoCAD and Mastercam. With AutoCAD, they produced detailed
3-D drawings of the engine to be used by the machinist for
manufacturing. Mastercam translated the input information into the
appropriate machine language for the mill. Mastercam's toolpath
verification feature enabled the team to generate a solid model of
the finished part, complete with every scallop, chamfer and
radius.
While the current Igniter 2000 is powered by a two-stroke
aluminum engine, PSI also has prototyped a 320 cc version of the
two-stroke that puts out 50-55 hp. According to Elvin, engine
displacements up to 600 cc are possible with this design. "We
probably are going hit the market with a 320 cc engine," says
Montgomery, "because our goal is at least 45 hp on our first
entry."
"Production models will start with fuel-injected two-stroke
engines, but PSI is working on an environmentally friendly
four-stroke engine, so that the Igniter 2000 can be "as green as
possible," says Montgomery. Four-stroke engines emit 97% less
pollution than conventional two-strokes, use half as much gas, and
keep all oil inside instead of discharging it into the water and
air. Also, the low-end torque of a four-stroke provides an ideal
powerband for driving through leaning turns, he adds.
Montgomery partnered with Wayne Morris and Tibor Nagy of Source
One (Brea, CA) to develop the Pro/ENGINEER files and refine the
billet engine even further in terms of strength and weight. The
first 100 test engines are being produced using sand-cast tooling.
Then Source One will optimize the engine design for die-cast
tooling. To improve the engine's hp:weight ratio even further,
Montgomery is considering manufacturing the production engines using
Irvine, CA-based Alyn Corp.'s Boralyn™metal-matrix composite
material, and its precision soluble-core technology. Boralyn is a
mixture of aluminum and a boron-carbide ceramic.
According to Robin Carden, founder of Alyn Corp., "Boron-carbide
is the third hardest material known to man. Even at high
temperature, it's harder than diamond. The Igniter 2000 is a Van
Gogh, and we want to be the diamond inside it," he says. GM's EV-1
engine cradle, golf shafts for golf clubs, and satellites are
currently produced using Alyn Corp.'s material and processing
technology, primarily because the Boralyn material is lighter,
stiffer, stronger, and very easy to fabricate, says Carden.
Alyn Corp. claims it can pressure cast one PSI engine every 30
sec, and the soluble-core technology will create passages inside the
engine that are as smooth as marble. "We are able to get very smooth
intake and exhaust ports on this engine," he adds.
Hefty handle. Standing on and controlling a
fast-moving, motorized surfboard through a "G-Force" turn requires a
long handle. The design team developed a custom, ergonomically
correct, ambidextrous handle unique to the Igniter 2000.
The throttle switches on the handle at the end of the arm pole
act as levers that let the rider regulate the supply of vaporized
fuel that goes to the engine cylinders. The dual throttle levers are
independent halves of the same universal cylinder/cam-type
mechanism. The mechanism consists of a rotating/sliding internal
centerpiece that imparts motion to a roller moving against its edge.
The throttle cam acts as the point of pull on the armpole cable.
"It's aggressive," notes Montgomery. "It doesn't take much pressure
on the throttle switch to speed up this craft."
To bring the craft's handle to reality, the PSI team used
Alias®AutoStudio TM computer software, a
three-dimensional (3-D) industrial design system. Alias Auto Studio
relies on mathematics to describe physical objects, and enabled
PSI's design team to create geometric models of the handle with
precision surfaces. They then used the 3-D Alias CAD drawing to
hand-carve preliminary foam models.
"Coming into this process we had our designers do ergonomic
studies so that the handle will fit the 85th percentile of people,"
says Montgomery. To produce a real-life, tangible plastic replica of
the handle, they used 3D Systems SLA-250 series stereolithography
equipment. Relying on the Alias drawings, the equipment directed
ultraviolet laser radiation onto a vat of polymer resin (liquid
plastic) to carve the 3-D model, which was cured in an ultraviolet
oven and then hand-polished and finished to specifications.
Dual-hydrostep. The "rocketship look" of the
Igniter 2000 comes from its streamlined, hydrodynamic, low-profile
composite hull-8-ft-4-inches in length. Throughout the past 20
years, Montgomery has hand-built numerous operational prototypes. In
designing and fabricating the Igniter 2000 hull, Montgomery and his
team used FARO Technologies FaroArm, a portable laser tracker
instrument with multi-axis, articulated arms, along with a CAD-based
measurement program. They digitally scanned the hull of a hand-built
Igniter 2000 model to create a digital "point cloud" on the
computer. Then, Freed Designs did the modeling in Alias.
In the software, the PSI team improved Montgomery's hand-built
design by lowering the profile by flattening the space in the hull
where the craft's non-directional jet-drive system-engine, pump and
propeller-is mounted. Another significant change: The engine is
housed in a totally leak-proof, watertight compartment with an
inflatable seal that makes the craft a "three-quarters submarine"
submersible. Riders can plunge underwater or float on the surface
without stalling, explains Montgomery, thanks to a clever one-way
valve on the exhaust and dual plurge valves on the intake.
Most popular, steered, sit-down personal water craft have a
flat-bottom/square siderail shape. During turns, those with straight
side rails can produce abrupt and unexpected moves that make the
craft prone to suddenly tipping over. In contrast, says Montgomery,
Igniter 2000 carves high-speed planing and turns without
trouble.
Igniter 2000
specifications
GENERAL SPECS
PWC style of use--Rear-mount Standup
Overall
length--100 inches (8 ft 4 inches)
Overall width--26
inches
Overall height--8.5 inches
Dry
weight--100-125 lbs
Color--Buttercup Yellow/Fire
Red
Starting--Electric
Propulsion
system--Non-directional jet-drive system (engine, pump
and propeller) axial flow, single
stage
Armpole--Four-foot long "armpole" steel cable and
a sleeved wire harness covered by injection-molded rubber
links the jet-drive system in the chassis to a handle/throttle
control assembly held by the rider in a closed-fist grip.
Handle/Throttle
Control Assembly--The modular handle assembly consists of
the grip, start/stop buttons, independent left-and-right thumb
throttles, speedometer and fuel gauges, and safety kill
switch. Sub-assemblies are attached to a steel backbone that
provides structural strength.
Grip--Removable and
replaceable, scientifically engineered finger grooves (to
prevent hand and wrist fatigue) coated in cushy soft,textured
sanitex/saniprene rubber and nylon laid over a thermoplastic
elastomer surface.
Throttle--Dual, independent
right-and-left thumb acceleration switches make the craft easy
to control with either hand.
Electrical Pod--A removable hood houses the electronics for
light-emitting diode(LED) fuel-level indicator displays
andliquid crystal display (LCD)speedometer.
Hull
Shape--Curved, hydrokinetic, "dolphinated"
Material--Composite
Nose--Tapered, pointed
Rear deck (Where the rider stands)--Flat,
level surface
Siderails--Surfboard contoured
Dual "hydrostep"bottom--Ideal for high-speed planing and
turns.
Decking material--Lightweight, textured compression-molded
ethylene vinyl acetate (EVA) foam
Engine
Displacement--250 cc
Horsepower--40 hp at 8,000 rpm
Cooling system--Inducted water
Carburetion--Single 40mm Mikuni BN or electronic fuel
injection
Lubrication--Premix
Ignition--Digital CDI
Thrust--350 lbs
Fuel capacity--3.5 gal w/0.6 gal reserve, vaporless fuel
system
Engine type I--2-stroke/forward mounted
Cylinders--1-cylinder with crankcase reed valve
induction
Engine type II--4-stroke with dedicated transmission
Cylinders--1-cylinder Camless four-stroke technology from
Specialty & Ball Valve Engineering, Inc. (Tustin,
CA) |
Partners in Design
Handle
Hull
Engine
|
Vaporless FUEL system
This patented fuel storage system reduces the number-one
safety and environmental threat related to fuel
storage-vapors. A rigid outer shell contains a flexible
double-walled bladder made of a pliable, composite material
that is impermeable to fuel. Hydraulic fluid fills the space
between the walls, allowing the bladder to expand just enough
to hold the amount of fuel received as it enters the empty
bladder.
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| The pliable composite material used
for the double-walled bladder is strong,
puncture-resistant, flame resistant, and withstands
extreme
temperatures. |
When fuel is consumed and the bladder empties, its volume
decreases, continuously contracting, and never allowing air
space to form. Without air contacting the fuel, vapors and
subsequent vapor hazards are eliminated, even when the tank is
empty.
Integrating easily into existing fuel systems, the
vaporless fuel system eliminates the need for costly venting
and on-board canister systems. It also prevents the loss of
fuel through evaporation, prevents contamination, and
maintains fuel integrity (including diesel and jet fuels).
Moreover, the design may potentially solve a variety of
problems in applications ranging from chemical storage to
contamination in water storage systems on recreational
vehicles.
Kevin Madison, Top Dog Systems, Box 508, Ridgewood, NJ
07451; Tel: (877)
668-2767. | |