The project began conventionally,
with designers from Crucible submitting a range of rendered sketches
of a re-designed front end. Due to the reverse engineering aspect
of the project, 3T asked 3D Scanners to digitise the front of the
car to provide a digital surface that could be read into SolidWorks.
Once a final design was decided upon, Crucible created a 3D CAD model
which was then supplied to 3T for SLS components to be built.
The chosen design was intended as a contemporary
update of the Smart car approach, and included separate front wings
to mirror the construction method used on the back of the car. The
ability of the Smart car’s body panels to be completely removed
and replaced within four hours allowed access to the chassis fixtures
and fittings, which gave fixed anchor points for the final design.
Critical components such as the door pillars and bumper fixtures
had to be considered, and the windscreen washer and brake fluid
reservoirs had to remain accessible to ensure the car’s performance
wasn’t compromised.
The first prototype of the new design was built
in April 2004 and fitted to the car for extensive functional testing
in real driving conditions. It was taken to exhibitions and roadshows,
and showcased at numerous customer sites. The components remained
intact on the car whilst being driven over 1,000 miles in all conditions,
including motorway speeds, along country roads and in a variety
of weather.
The close working relationship between 3T and Crucible
enabled the two companies to develop the project in just 20 days;
from the initial briefing and concepts through to the completed
design and finished SLS components being produced. The consistency
of design personnel and the ability to have face-to-face meetings
is the preferred style for both companies – having to visit
a client, pitch the idea, await feedback and then start the cycle
again once modifications have been made, can be extremely time-consuming.
Modifications to the parts were easily made as the
project progressed, and as the design evolved any issues raised
were instantly rectified. For example, after the first batch of
road testing it was found that the corner edges of the front wings
clipped the road slightly when the car was subject to body roll.
Tim Plunkett, CEO of 3T
says “Being able to modify a design and a prototype cohesively
is something we always emphasise as being imperative when discussing
new product developments with our clients as, in reality, several
iterations can be required before the final design is produced.”
A second iteration of the design was built and fitted
onto the car in Autumn 2004, and further road testing carried out.
Again, over 1,000 miles was put on the clock in a variety of road
and weather conditions. In overnight freezing temperatures during
November and December the car was parked outside, with no detrimental
affect to the SLS components.
3T’s ability to build single piece parts up
to 700x380x580mm reduces the
need for joints and additional assembly and thereby increases their
functionality. Further, it has led to dramatic reductions in production
lead-times. “In today’s environment, no-one seems prepared
to wait more than three weeks irrespective of the size of the project”
says Plunkett.
“Capacity is essential as many projects now
contain 10s or 100s of parts”. However, the ability to produce
larger, higher quality prototypes in a shorter time frame, but at
a similar cost, can have a knock-on effect of raising customer’s
delivery expectations. “If we deliver a finished model within
a tight deadline, customers know our capabilities and this pushes
up our own benchmark” says Plunkett. “This can result
in a higher expectation next time they place an order and, in some
cases, we’re expected to improve on the delivery date still
further”.
Tim Plunkett summarises “High-tech design
software can provide photo-realistic images ideal for the concept
stages of product development. However, a physical prototype speeds
up the approval process and can be used in functional testing, assembly
trials, wind tunnels and marketing photography. This project has
proven, beyond doubt, the capability of our SLS prototypes.”
The project is ongoing with further modifications
being made to the design and road testing being carried out. The
car is being taken to exhibitions and client sites so that the true
functionality of the parts can be viewed firsthand.
Read Crucible’s Press Release here
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Introduction
