"The broken pieces could be glued together - carrying the scars of the incident forever, and with them, a permanent depreciation of the whole vehicle. That was not an acceptable outcome."
// CASE STUDY
When the light goes dark
How Mapeex recreated a discontinued catadioptric turning light for a historic race car - without a mold, without a spare, and without compromise.
The Challenge
During the handling of a historic race car in a parc fermé, a barely visible obstacle made contact with one of the vehicle's bespoke turning light lenses. The damage was minor in appearance - but the consequences were anything but.
The turning light in question was not an off-the-shelf component. When the car was originally built, every exterior detail was tailor-made for the project. Decades later, the part was long out of production, the original manufacturer had destroyed the tooling used to make it, and no replacement was available anywhere in the world. The car's owner faced a situation with no easy exit.
The technical challenge compounded the commercial one. The interior surface of the lens features a complex catadioptric geometry - a precise array of prismatic reflectors that direct and diffuse light. Replicating that geometry is not a matter of rough approximation; a deviation of even a fraction of a millimetre changes the optical behaviour of the finished part. In the original production era, a single mold of this complexity required fourteen weeks to manufacture and cost approximately forty thousand dollars at the time.
The constraints were unambiguous:
- No original spare part available anywhere in the world
- Original manufacturer's mold destroyed - no reference tooling
- Complex catadioptric internal surface requiring sub-millimetre accuracy
- Fixed exhibition and racing schedule demanding rapid resolution
- Vehicle's concours value at risk if any visible scarring remained
With the opposite-side lens still intact, reverse engineering presented itself as the only viable path. But it required an engineering team with the precision, toolchain, and methodology to make a mirrored recreation indistinguishable from the original - optically, geometrically, and cosmetically.
The Approach
1 · Assessment
Both turning light assemblies were removed from the car for evaluation. Each lens is a two-piece bonded construction: a housing and a translucent outer lens, itself divided into a lower orange-tinted section and an upper clear section. The damaged right-hand lens was catalogued and set aside. The left-hand lens — undamaged and in excellent condition — became the geometric reference for the entire project.
2 · Engineering
The left-hand lens was stripped, cleaned, and prepared for high-precision 3D scanning. To capture every feature of the catadioptric surface - including areas partially obscured by the housing - high-definition reference prints of hidden zones were produced and incorporated into the scan model. The result was a complete, watertight digital model of the lens. A mirror transformation of that model produced the right-hand geometry. Both STL files were then used to produce the production molds, with iterative cycles of printing and testing until conclusive reliability was confirmed.
3 · Model creation
The lens material needed to match the original's optical character precisely - both in clarity and tint. Optical-clear, UV-resistant resin was selected as the production medium, available in the exact tonal specifications of the original. Controlling for air bubble inclusion during the casting process was a critical quality criterion: even minor inclusions affect both the aesthetics and the functional light distribution of the finished component.
4 · Production & Validation
The quality of the final part is a direct function of the quality of the digital model - and that model was built to the highest possible standard. The molds derived from it carried that precision through to the finished components. Upon delivery, the new lenses were scanned a final time and compared against the original geometry. The result confirmed reproduction within a tolerance of just a few microns - well within the threshold for a perfect fit.
Unlike a standard reverse-engineering bureau, Mapeex mapped all hidden surface geometries before committing to the digital model - ensuring the final part performs exactly as the original, not merely resembles it.
The Result
Within a matter of weeks - a fraction of the time a conventional mold-making process would have required - the replacement lenses were delivered. They fit their housings without rework. The tint matched the originals exactly. The geometry was indistinguishable from what left the factory decades ago.First Time Right
The lenses fit their housings on the first installation. No adjustment, no rework, no compromise.
On Time
Delivered within the window demanded by the vehicle's exhibition and race schedule.
Micron-Level Accuracy
Final scan comparison confirmed reproduction within a few microns of the original geometry.
Concours Condition Restored
The historic car returned to its full original standard - with no visible trace of the incident.
The car's owner received the vehicle back in the condition it deserved - pristine, period-correct, and road-ready. The replacement lenses carry the same optical properties as the originals, with a surface quality that in some respects exceeds what was achievable with the manufacturing processes of the era.
Why Mapeex? Key Differentiators in this case
First Time Right - Every Time
Every part leaves with production documentation precise enough to guarantee fit on first installation. The iterative scan-to-mold validation cycle eliminates deviation before a single production unit is cast.
Full Context Engineering
Mapeex does not simply reverse-engineer a shape. The team analyses optical behaviour, material properties, environmental exposure, and fitment loads - then selects materials and processes for reliable long-term performance.
30 Years of Motorsport Precision
The methodology was developed in an environment where parts must perform under extreme conditions, to tight deadlines, with zero margin for error. Every restoration client benefits from that standard, regardless of context.
Trusted Supplier Network
Mapeex directs production through a curated network of specialist suppliers, with quality supervised at every stage from digital model to finished component.
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