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Additive Manufacturing

Aston Martin Racing used 3-D printing to produce prototypes

for concept and testing of the AMR-One (LMP1

class) race car for the Intercontinental Le Mans Cup.

Dream Cars Come to Life

Direct digital manufacturing speeds the

3Rs—rebuild, restore, and replicate.

Jim Lorincz

Senior Editor

Step outside of the high-volume, highly automated

world of production automotive manufacturing

(which is well documented in this issue of

Manufacturing Engineering) for a few minutes,

but not too far out. There’s a fascinating world

populated with car enthusiasts who restore,

rebuild, replicate, and race some of the sleekest cars that

ever rolled out of someone’s garage or specialty build shop.

Their “rides” include muscle cars, replicas, newly built highperformance

NASCAR race cars, or open cockpit road racers.

And they all share one thing in common—they all need fast

turnaround and economical fabrication of components and

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Additive Manufacturing

the fixturing to produce

them. Some simply

replace original parts;

others upgrade components

to handle a more

powerful engine, customize

the car, or meet new

regulations.

Additive manufacturing

(AM) technology continues

to grow in importance

as a time-saver and

a budget extender both

for direct digital manufacturing

(DDM) in-house

or by relying on service

bureaus. The RedEye On

Demand digital manufacturing

service has more

Roaring Forties used RedEye On Demand’s direct digital

manufacturing services to build a jig for the fuel line, which

could be used both as a fixture for aligning assemblies and

as a “go/no go” gage for its GT40 ICV kits.

than 100 fused deposition modeling systems manufactured

by its parent company, Stratasys Inc. (Eden Prairie, MN), and

is capable of quick turnaround, processing CAD data directly

into prototypes, fixturing, or final parts.

Fused deposition modeling is an additive-manufacturing

process that creates plastic parts by applying real productiongrade

thermoplastics, the same ones used in injection-molding

processes, in layers from the bottom up. Repeatability,

quality parts appearance, and reliable function are easily

achieved in low-volume production applications for components

or fixtures.

Roaring Forties (RF; Thomastown, Victoria, Australia) is

a manufacturer of replica kits for one of the most famous

GT cars, the Ford GT40. The GT40 was Henry Ford II and

Ford Motor Co.’s (Dearborn, MI) entry into road racing in the

1960s. The GT40 name is derived from Grand Tourisme,

which measures 40" (1.02-m) high at the windshield. The

GT40 is justifiably famous for winning the 24 Hours of Le

Mans four successive years from 1966 to 1969.

Roaring Forties provides Individually Constructed Vehi-

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cle (ICV) kits to enthusiasts who build the cars themselves.

(In Australia, it is illegal for Roaring Forties to assemble the

car.) The GT40 can be built by enthusiasts in four stages

at a cost, according to RF, of about AU $90,000. Roaring

Forties provides every component required

from start to finish in some 160

separate kits for sequential build.

When an emission regulation

changed, Roaring Forties was required

to fit a new engine into the existing

chassis. One of the critical changes

was to the brake and fuel-line harness.

The companies turned to RedEye On

Demand, because of its experience with

its DDM capability for building parts

for development testing and end use.

In this case, RF recognized that the

manufacturing technique could be used

to build a simple jig for the fuel line

which could be used both as a fixture

for aligning assemblies and as a “go/no

go” gage.

The ability to manufacture parts

like jigs, fixtures, and tools on demand

allows processes to be optimized and

implemented in a shorter timeframe.

Parts for fixturing and tooling in the

automotive manufacturing environment

need to withstand the harsh environment

of high temperature and vibration

and be light weight and portable. And,

as in the case of Roaring Forties, when

parts require design changes, fixtures

have to be altered quickly.

When Roaring Forties co-owners

Jonathan Klopsteins and Paul Bottomley

heard that digital manufacturing

technology could be applied to jigs

and fixtures, they gave the go-ahead to

give it a try. RedEye looked at the ABS

prototype of the harness and how it was

manufactured and suggested using

polycarbonate (PC) material, reasoning

that the higher melting point would

allow Roaring Forties to solder brackets

on prior to brazing. Because the jig isn’t stressed during use,

RedEye engineers also suggested building it with a sparse fill,

saving build time, piece cost, and materials.

Fixtures are most frequently used in holding, assembly

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Additive Manufacturing

and alignment, calibration, test hardware and prototyping.

RedEye On Demand saved the Roaring Forties team time

and money on fabrication and assembly tools. Digital manufacturing

technology reduced fixturing manufacturing time to

days and eliminated machining

with its longer turnaround time

of four to six weeks for machining

and assembling metal,

wood, and other common fixturing

materials.

According to Roaring Forties,

once you hand a part to a customer,

there are a multitude of

ways of perceiving quality. Parts

not only need to look good and

part doesn’t mate up with another, it will result in an unhappy

customer—something we strive to avoid,” the co-owners aver.

You might not think about appearance as much as function

when it comes to NASCAR cars, but when Joe Gibbs

Racing (JGR; Huntersville, NC)

needed an enclosure for heater-control

components, appearance and function

were both considered essential.

The challenge for Joe Gibbs Racing

was to produce a part that would act

as an enclosure for the heater control

components to be used in the

cars during races each week. These

components include wires, gages, and

switches. The enclosure itself would

be fit for the purpose at hand,

they need to work well as part

of an overall assembly. “If one

Prototyping produced a split plenum end use part

that was welded together for superior performance

for a restored 1970 Ford Mk1 Capri.

be composed of two pieces. The main

body would include recesses for the

switches and gages with enough room

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Joe Gibbs Racing chose RedEye On Demand to produce an

enclosure for heater control components for function, appearance,

and fast delivery.

on the inside to route wires and other electrical components.

The second part would be a thin-walled backing plate used to

close the open face of the main body.

The part itself needed to be strong enough for racetrack use

and accurate so that the gages would fit well in the recesses

designed for them. It would replace a crude hand-fabricated

piece that was functional but not visually appealing. In addition,

the old part required fabrication time and CNC time that the

racing team needed to eliminate.

“Our product has to be performancedriven,

but it also has to look good.”

Joe Gibbs Racing, which has its own CNC machine shop,

also has a Stratasys machine, a Fortus 400mc 3-D production

system. It knew the capabilities of direct digital manufacturing,

and had added the machine for quick turnaround on prototyping

parts, especially using thermoplastics like polycarbonate

and polyphenylsulfone. It takes just 15 min from completion

of CAD design to start building the prototype. JGR, however,

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Additive Manufacturing

determined that its in-house resources would not be adequate

to handle production of the required large number of parts in

the 10 days until the racing season was scheduled to begin.

JGR contacted RedEye On Demand to produce the part,

because of its fast turnaround and choice of materials available

to provide the right strength and surface finish. The final

parts were delivered to JGR within one week without involving

any JGR personnel involvement. The 30 new parts took about

30–35 hr each to produce. Traditional manufacturing might

have taken four to six weeks. The parts, which were made from

ABS black, didn’t require additional surface finish work such as

sanding or painting. This last point was particularly important

from JGR’s point of view. “Our product has to be performancedriven,

but it also has to look good,” explains JGR’s Mark

Bringle. “We can’t have a fast car that looks terrible. It’s not

good for the sponsor. With RedEye’s service, the products were

appealing, the functionality was perfect, but the big thing was

the delivery time.”

In custom restoration, one change by Ivan Viduka to his

1970 Ford Mk1 Capri—replacing a standard engine with a

3.0-L quad cam to compete in the Australian Historic Racing

Series—led to the need to customize other components. A new

high-performance air intake system was needed to ensure top

performance. With no major financial backing, Viduka’s goal

was to reduce costs associated with low-volume tooling and

machining, so he approached RedEye On Demand for their

digital manufacturing services.

“The ability to manufacture parts like jigs,

fixtures, and tools on-demand allows

processes to be optimized and

implemented in a shorter timeframe.”

An initial design concept for the intake plenum was developed

with CAD software and sent to RedEye where a rapid pro-

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Additive Manufacturing

totype was created using polycarbonate (PC) material. Due to

its suitable heat-resistance properties, PC possesses lower yield

strength than aluminum, which would normally be used for this

application. A suitable thickness was applied to the design with

the aid of CAE analysis to ensure the plenum component was

able to resist maximum engine vacuum changes during snap

throttle events and backfire.

No additional machining was required, because all of

the intake plenum features and holes were digitally manufactured

using PC. All mounting holes were heli-coiled for

additional strength so correctly sized fasteners could be

used and sealing of the plenum was maintained. The initial

design was used for development testing and included idle

speed control, PCV, and vacuum bosses ready to go without

addition machining required.

As part of the testing phase, improvements to the design

were identified. In this case, the new design included a second

throttle body unit that increased horsepower while bosses and

ribs added increased structure to the lower mounting surface.

3-D Printing Makes Aston Martin LMP1

Race Car A Winner

Aston Martin Racing (AMR; Oxfordshire, England) used 3-D printing to meet an

aggressive development schedule for the AMR-One (LMP1 class) race car. The

Stratasys Dimension 3D Printer was used to mock up the chassis, driver controls,

and engine, producing prototypes for the concept and testing and accomplishing

the goal in less than six months from Autumn 2010 to the end of February 2011.

AMR selected the Dimension machine for its rapid prototyping capabilities after

seeing the speed and quality of the parts produced for the Prodrive-run rally

team. Having the machine on site helped the race team design, test, and build

a complete car to meet the tight deadline for entry into the Intercontinental Le

Mans Cup (ILMC). AMR-One features a new custom carbon-fiber chassis, an

open cockpit, and a significantly down-sized engine, all of which required testing

during the building process. The Dimension machine was used primarily for

designing and testing the engine parts as well as for mocking up the chassis and

driver controls to meet design regulations of ACO, the Le Mans governing body.

“When we received the final sign-off to build the car for this year’s ILMC, using

rapid prototyping was a no-brainer for us, as we had a tight deadline to meet.

Most of the engine was prototyped on the Dimension machine, which also proved

very useful for the early stages of determining the driver fit for the car,” explains

George Howard-Chappell, AMR technical director. “Without the 3-D printer, we

would not be testing the car today. Following the success with the AMR-One, we

hope to utilize the capabilities of another Stratasys machine to help build and

deliver end-use parts for future cars.” One item being considered is the front wing

splitters used for aerodynamic flow.

Most of the AMR-One (LMP1) class race car including the engine

was prototyped on the Dimension machine.

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After testing of the second design, the model was updated with

more beneficial changes and a new prototype was created using

sparsely filled ABS to produce casting patterns. A split plenum

design was favored to avoid the need for an additional core

model. The two halves of the plenum

were machined and welded together.

Working with good engineering and the

team at RedEye On Demand, Viduka was

able to develop more than 350 hp [261

kW], giving him enough power to drive

circles around his competition.

The ability of fused deposition modeling

to speed automobile restoration, customization,

and production is nowhere

illustrated better than in the case of a Pit

Viper, a GT500E-inspired Mustang that

started life as a 1968 Fastback. Brook

Phillips and his team at Total Performance

Inc. (Wichita, KS) began the

process by selecting 3-D scanning and

the fused deposition modeling technology

for nine components: two pair of side

scoops, two hood scoops, front grill, rear

bumper, and center console. The goal

was, of course, perfection in fit, finish,

and symmetry. To achieve the 1/16"

(1.58-mm) precision and consistent

flush and gap that Phillips wanted, he

turned to Realadi Inc. for TPI reverse engineering

and 3-D scanning tools and to

Stratasys for rapid prototyping and direct

digital manufacturing.

Through its RedEye On Demand

service group, Stratasys built onequarter

scale and full-size models and

manufactured the finished parts for

the Pit Viper. The process showed that

restoring vehicles no longer needs to

be a laborious process. Phillips and his team found that the

procedure can be accelerated by the DDM technology, saving

both time and money, while meeting critical symmetry and fit

objectives. ME

Want More Information?

RedEye On Demand, go to

www.redeyeondemand.com,

or telephone 866-882-6934.

September 2011 | www.sme.org/manufacturingengineering 101

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