Super Polo wheel-arch louvres manufactured in carbon-filled nylon
A Super Polo required left- and right-hand front wheel-arch louvres, but no drawings or suitable off-the-shelf parts were available. The arches were scanned on the vehicle, checked by hand, modelled in SolidWorks and test fitted in PLA before the final parts were printed in PA12-CF.
The requirement
The front wheel arches required matching left- and right-hand louvres. No drawing was available, and the mounting surface curves in more than one direction, so the geometry had to be taken from the vehicle.
The visible fit along the arch was the critical requirement. A small error in the mating surface would leave a gap or cause the louvre to sit unevenly.
Measurement and CAD
Both arches were scanned on the vehicle using iPad Pro LiDAR. The scan provided the overall surface shape, while key distances and mounting references were checked manually.
The reference surfaces were brought into SolidWorks 2026 and used to develop the louvre geometry. Each revision was exported as an AP214 STEP file for manufacture.
PLA test fitting
Each revision was first printed in PLA and checked directly against the wheel arch. These test pieces were used only to confirm the mating surface, position and visible fit before committing to the final material.
PLA kept the iteration time and material cost low, but was not specified for the finished exterior parts.
Final manufacture
The final pair was printed in PA12-CF, a carbon-filled nylon selected for stiffness, thermal performance and its ability to retain the thin louvre geometry.
The abrasive filament required a 0.6 mm hardened-steel nozzle and hardened extruder gears. The material was dried before printing and remained in a heated dryer while feeding the printer.
The first PA12-CF prints showed blobs and stringing even after several days in a filament dryer. The spool surface had dried, but moisture remained deeper in the winding. A 12-hour drying cycle at 85 °C, with the spool turned four times, corrected the problem. PA12-CF is now dried thoroughly before the first print and is fed from the dryer throughout manufacture.