The world of vehicle restoration has recently seen a resurgence in capabilities with the introduction of 3D scanning. PES reports.
In the past, the relatively high cost and complex operation of such scanning technologies meant this was exclusively the domain of specialist organisations, making 3D scanning out of the reach of the car restoration market sector. However, with the introduction of handheld scanning systems, 3D scanning has now become far more accessible for 3rd party ‘bureau’ service providers.
Nonetheless, one of the inherent problems often associated with these services is an inability to deliver design or finished CAD model data that accurately meets the end users’ real needs. For example, the file format may not be correct for a downstream process, or the CAD is supplied with a quick auto surface rather than a detailed surface creation.
Capture Point is a bureau service provider with a difference. Firstly, owner Doug Larkin has more than 25 years’ experience within the automotive industry, having served at both Land Rover and Aston Martin within engineering and design.
His experiences cover studio design (clay modelling) and associated processes such as surfacing and design feasibility studies. In addition, Mr Larkin has had many years of experience with 3D scanning, producing point clouds and reverse engineering with a wide range of systems. To further improve and expand his scanning capabilities, he has now invested in the latest technology offered by Measurement Solutions, namely the Creaform MetraSCAN 3D.
The combination of the arm-free handheld MetraSCAN 3D scanning system and the C-Track dual-camera sensor forms a powerful duo that generates highly accurate scan data on any type of surface, both in the laboratory and on the shopfloor.
When combined with the HandyPROBE Next, this complete solution combines probing and scanning to increase the reliability, speed, accuracy and versatility of any scanning process.
Mr Larkin comments: “The MetraSCAN 3D solution allows total freedom of movement and offers us unique scalability from just 1m up to over 16m³ in volume.”
This flexibility is vital for a service provider due to the many diverse applications in the automotive, yacht, train and shipbuilding industries.
Mr Larkin explains: “Additionally, due to the enormous variety of projects that we encounter, component materials were a major factor in selecting the MetraSCAN 3D. We need the capability to take a single product to customers with complete confidence that all materials can be scanned, ranging from shiny or polished surfaces through to matt or gloss Black paint. For example, the Classic Car market is very reluctant to apply powder or photogrammetry targets to the painted surfaces. With the MetraSCAN 3D, we require none of these.”
Re-building a classic icon
Following the investment, Capture Point recently completed a new ‘Buck’ design for a classic Aston Martin DB5 build project. A car body Buck acts as a master pattern for a vehicle, having all the profile data visually and mechanically required to make repeat panel shapes for a car body or car shell manufacture. In order to generate the Buck design, Mr Larkin firstly had to laser scan the existing DB5 in its entirety using the MetraSCAN 3D without using targets or powder.
He comments: “Originally our intention was to scan one half of the vehicle and mirror the data to create a symmetrical design. However due to the speed of the MetraSCAN 3D compared with previous methods using photogrammetry, we were able to save half a day of post processing time, so we decided to scan the whole vehicle.
"This inadvertently highlighted some significant design considerations, as unbeknown to us the original DB5 had inherent differences on the left and right-hand sides of the vehicle, which critically affected the shut lines of the front door, the curvature form of the fender and the profile of the windscreen surround. This was the nature of the original ‘hand-built’ vehicle production process, as also confirmed by the coachbuilder we were working with.”
The design intent was to produce a symmetrical Buck using Creaform’s VXmodel software, enabling Capture Point to create a master mesh model which maintained the desired shut lines from the right-hand side blended with the desired fender profile of the left side.
Typical examples of the vehicle anomalies highlighted by the scan data include a 10mm difference in fender curvature on the original DB5. Once the master mesh had been finalised, Capture Point used modelling software such as SpaceClaim and SolidWorks to create a finalised CAD model and machinable block design for the Buck, which was also manufactured in-house.
Vehicle bodies and individual components
Another example of the use of 3D scanning is KW Special Projects of Brackley. KWSP is a high-performance engineering provider that uses the capabilities and technologies of the motorsport industry to provide turnkey engineering programme delivery, from concept to manufacturing and assembly.
Key to KWSP’s approach is the use of digital manufacturing techniques such as additive manufacturing (3D printing) that facilitate bespoke solutions to engineering challenges. KWSP’s core capabilities include lightweight structures and composites, powertrain integration, control systems and automation and full system integration, with clients across automotive and mobility, performance sport and manufacturing.
[caption id="attachment_40415" align="alignleft" width="319"]
Surfaced CAD model ready for machining[/caption]
KWSP was recently challenged with re-engineering a vital component of an iconic classic car. The Alfa Romeo Tipo 33/3 is one of only 12 cars made by the Italian manufacturer in the late sixties to compete in the World Sportscar Championships.
Run by Autodelta, the works team, the car initially struggled, but found major success in 1971 at races in Buenos Aires, Sebring and Brands Hatch. It went on to gain a faithful following, and even played a starring role in the Hollywood movie, Le Mans, alongside Steve McQueen.
One of the remaining Tipos is being run by UK-based Martin Stretton Racing, a leading historic race car restoration specialist. Like many race teams and restorers alike, Stretton is faced with a challenge that will only get harder as historic cars become older – the replacement of original parts.
Emerging industrial technologies, such as additive manufacturing and 3D printing are transforming the sector’s response to the spare parts problem in the historic motorsport market. And when such know-how is used in conjunction with digital scanning techniques, this makes for a powerful mix. Employed by skilled engineers, these tools can be used to help re-manufacture one off, original parts quickly and often at a fraction of the cost of traditional methods.
The engineering challenge
Faced with badly damaged parts that have kept its Alfa Romeo Tipo off the road for several seasons, Martin Stretton Racing turned to high performance engineering consultancy KWSP, to bring its rare works 1971 Alfa Romeo Tipo back to the grid.
The car’s original, naturally aspirated, three-litre V8 engine was in good working order, apart from a problematic engine cover, which had deteriorated significantly in recent years, and had been subject to numerous running repairs. As an integral working part of the vehicle’s powertrain, the poor condition of the front cover had become a major issue. The final straw came when it failed to start.
Using a Creaform HandySCAN 3D from Measurement Solutions, KWSP was able to provide a novel and rapid solution to the problem. The HandySCAN 3D is a handheld 3D laser scanner, offering an accuracy up to 30µm. Being completely portable and arm-free, the scanner can tackle the most complex of scanning applications with ease, providing high quality scan data very rapidly. KWSP scanned the badly corroded engine cover, along with the original water pump and housing, transferring the scan data directly into its existing CAD for engineering change and manipulation, to create a digital model of the part.
Once the company had a finished digital asset, a prototype part was printed in a high-performance thermoplastic, PC ABS. Once 3D printed overnight, the cover prototype was fitted to the engine to confirm proof of concept, then giving KWSP the confidence to commit to final manufacture.
Martin Stretton explains: “This is a rare car – only one of twelve that were made and run by Autodelta – so when we were searching for a replacement cover, the options were limited. We found several alternatives that were close, but none of them were exact matches for our Alfa Tipo 33.3. In the end, we had to explore other avenues.”
Throughout these journeys, Capture Point and KWSP have been supported by technicians from Measurement Solutions. As the Creaform partner in the UK since 2005, the company has a vast experience of 3D scanning applications in a diverse range of industries, from automotive and aerospace design and manufacture through to prosthetics, dinosaur skeletons, consumer goods and PlayStation games.
The complexity in the above examples illustrates how important a combination of experience, software capability and the application of the correct scanning hardware will serve to save an end user significant time and money, and ensure that they receive a derived design to meet their exact requirements.
Measurement Solutions https://measurement-solutions.co.uk
