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This is the direction that the people at Hypercar think autos should takenot
merely in terms of body design, but with regard to its composite-intensive manufacture.
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Hypercar Inc. (Basalt, CO) is not an automobile manufacturing company. Yet
the people there want to transform the capital-intensive industry by developing
a better way to make cars. The small advanced technology development company
has put together what by automotive industry standards is a microscopic team
of seven engineers tasked with finding a
better way to make cars. Its development goal is to design a vehicle that can
achieve 100 mpg and almost zero emissions, yet has the same passenger and cargo
capacity as a mid-size SUV, and can be profitably produced at the 50,000 unit
per year level. The prototype of this vehicle is named, aptly enough, the Revolution.
The Virtuous Cycle. Hypercars clean-sheet design for super-efficiency
started with a radical reduction in weight. It has been estimated that less
than two percent of the energy a vehicle uses actually ends up transporting
its passengers. The rest is lost to aerodynamic drag, rolling resistance and
hauling around three or four thousand pounds of steel and glass. Reducing weight
begets a virtuous cycle in which powerplants, braking and steering systems and
suspensions can be downsized because there is less weight to propel, stop and
turn.
With this in mind, the Revolutions design team jettisoned the traditional
steel body in favor of composite structures that provide strength and rigidity
characteristics comparable to steel, at half the weight. This decision alone
opened the door to a panoply of advantages...and disadvantages.
The Upside. First, the advantages: Using composites as a body material can
greatly reduce the complexity of a vehicle by markedly decreasing part count.
Hypercar estimates that a conventional car body is constructed of between 250
and 300 separate stamped steel parts. By contrast, since plastic can be formed
into more complex shapes than steel, the Revolution has only 14 major components
and a total of only 62 components in its entire structure.
Tooling costs can be minimized since you dont need the expensive hard
tools necessary to stamp all of that steel, nor do you need the complex jigs
that hold metal parts in place while they are welded. (The Revolutions
structural components have been designed with self-aligning joints that reduce
the need for jigs.) And speaking of the weld department, scratch that too, and
all the fixed investment that goes into it.
Ditto for the massive investment and emissions headaches of the paint department.
The Revolutions thermoplastic exterior body panels have molded-in color.
| If This Is Such a Good Idea...
So if making cars with composites is such a good idea, why aren't traditional
vehicle manufacturers aggressively pursuing the technology? David Taggart, Hypercar's
senior vice president of Product Development, answers, Because no one
is asking for it. At least not on the level that we've tried to design
to. No one is saying I need an SUV that gets 100 mpg. Customers are saying give
me an SUV that gets 22 mpg, and you don't have to take a lot of weight
out to get to that. Until the challenge gets a little more dramatic you will
get what you get now, which is a few tweaks here and there with a slow progression
toward something that Americans might say is economical but that the Europeans
say is a joke. Until there is a demand for product it won't be delivered.
Also, people don't realize that they have a choice. Part of what we are
trying to do is show companies and the public that there is another way to design
and build cars that delivers much more attractive economy and emissions.
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The Downside. Now the disadvantages: Carbon-reinforced polymers like those
used for the Revolutions structure are typically laid up by hand at the
rate of 30 or 40 plies per 1/8 in., making it a very labor intensive process.
Unlike steel part manufacture, where most of the investment goes into hardware,
with composite fabrication, the bulk of the cost goes to labor. As volumes rise,
steel parts get cheaper, but composites have a built-in recurring labor cost
that becomes prohibitive at higher volumes. Also, though the soft tooling needed
for composites is cheaper than the hard tools for stamping steel, it wears out
faster. So, at higher volumes, composite production tooling costs rise significantly.
As for thermoplastic panels, their cycle times are much longer than those
for stamped steel, and molded-in color cannot yet reliably achieve class A surfaces
on large panels.
The Solutions. To deal with the labor-intensiveness disadvantage, Hypercar
is trying to take experience gathered in the aerospace industry and modifying
it to fit automotive. David Taggart, senior vice president of Product Development,
and leader of the core design team, spent much of his career at Lockheed Martins
Skunk Works focusing on using carbon-reinforced materials for aircraft. He says,
While the requirements for a car are very different than an airplane,
they are not so radically different that you cant use the same approach.
The biggest difference on the car is that we had a production volume requirement
that is higher, but we also had different requirements for tolerances and specs
on the materials that gave us some freedom and latitude on how we came up with
solutions. So we exploited aerospace thinking but we blended it with production
reality.
The result is a proprietary production process. Though Taggart wont divulge
details, it is clear that his team is developing an automated process that can
generate composite structures. He says, We are convinced that you cant
get the quality, repeatability and cost necessary by doing it by hand and using
a lot of labor.
Hypercar has set itself the goal of developing technologies that can cost-effectively
produce Revolutions at the 50,000 unit per year level. According to Taggart,
no company has been able to make composites affordable at that volume, but he
reckons that that is the number necessary to get the automakers to sit up and
take notice.
Currently, the project has progressed to the point that if the design was frozen
and all efforts were placed on scaling up production, Taggart thinks the Revolution
would be price competitive with the BMW X5. The next phase will be a two-year
engineering/manufacturing development period after which the goal is to be price
competitive with a Ford Explorer.
Hypercar is not looking to become an automaker. The company sees its role as
a developer of the technologies needed to make cars. It wants to license its
handiwork to existing makers or companies that want to produce niche vehicles
at low investment rates. And, if Hypercar can deliver a super-efficient car
for the price of a conventional one, it may have lots of takers.
Beyond the Body Structure
The extensive use of lightweight composite structures has allowed the Hypercar
design team to achieve a curb weight of a mere 857 kg, which is less than half
the weight of the similarly-sized Lexus RX300. But weight savings alone will
not get the Revolution to its product requirements of 100 mpg with zero emissions.
Here are some of the other technologies at work:
- Electric motors on each wheel powered by a hydrogen fuel cell
- Michelins PAX wheel and tire system that reduces rolling resistance
by as much as 50% over comparable vehicles
- Integrated digital electronic control for all systems that reduces wiring
complexity, mass and assembly time
- Sidestick steer-by-wire system that eliminates the steering wheel and
column and the need for an adjustable drivers seat
- Optimized aerodynamics that are estimated to be 30% to 40% better than
a conventional SUV.