Creating Aftermarket Automotive Parts

If a part is not made by the original manufacturer it is considered to be an aftermarket part. However, aftermarket automotive parts can range from near identical OEM replacements or be modified to suit a new purpose. When creating aftermarket automotive parts the OEM part must first be reverse-engineered to ensure proper part fitment. A customer reached out to us, Applications 3D, with a unique project of modifying an OEM automotive part.

The customer, SMY Performance, is primarily an aftermarket parts manufacturer for Subaru vehicles. The project involved designing a new gauge cluster instrument bezel for the Impreza/Forester. Furthermore, this new cluster would feature two pods on either side of it. Additionally, the purpose of these pods is to give the ability to run gauges on the car that it typically would not have. These gauges are usually run in modified cars to read out values such as boost level or ethanol content. When creating the new product it was important to make the gauge pods the most universal size possible. 

Aftermarket Automotive Part Creation

Reverse Engineering the OEM Part

The product design work was started off by acquiring a stock gauge cluster bezel from an existing vehicle and 3D scanning it in high resolution to capture the current shape of the part. The 3D scan also enabled the measurement of mounting/attachment clips where the part attaches to the stock vehicle. Using our Steinbichler Comet White Light Scanner we captured millions of highly accurate points. These points are then triangulated to form the triangulated mesh that would be used in the next step of reverse engineering the OEM part. Furthermore, reverse engineering this part and creating an OEM quality CAD model ensured proper fitment and consistent looks with the OEM styling. 

Product Design of the New Gauge Bezel 

During the next stage of designing the new gauge bezel, it was crucial to communicate with the customer during the entire process. The reverse-engineered 3D CAD model from the previous step was used as the basis of the new design. Multiple renditions of the part were made until the final design was agreed upon. The key design was the positioning of the new gauge pods as well as their styling. Additionally, these pods were designed to flow nicely with the OEM part design. Not only that but they were designed to not be too intrusive and not block the OEM gauge cluster in any way. 

3D Prototyping of the Designed Bezel

With a CAD model created, it was time to have a prototype part created. This is to ensure that the part has the right fitment to the OEM locations as well as ensuring the new gauge pods look and fit well. This prototype was made by selective laser sintering (SLS) 3D printing. This form of 3D printing uses a powder, in this case, Nylon 12, and uses a laser to fuse the powdered material together. This process is very common for rapid prototyping because it yields very accurate results in a relatively short time frame. The 3D-printed prototype yielded great results and fit the vehicle better than the OEM. Now that the design was validated, it was time to move on to production. 

Creating a Production Ready Mold

Since the tooling costs can be substantial, it was decided with the customer to develop a prototype aluminum production mold. An aluminum mold is much faster to manufacture and is cheaper to machine than a hardened tool steel mold. Additionally, the prototype mold was designed to include hand-loaded inserts for creating the pockets and other part features that hindered the ejection of the part. Hand-loading molds are cheaper to produce than an automatic steel mold but has a longer cycle time per part. This was acceptable because these parts were going to be carrying a limited run production and initial costs would have been prohibited if a steel mold was used.

The machining of the actual mold was done using a 5-axis CNC machine. The mold was then hand polished after machining to ensure a smooth and flowing finish. During this time the OEM texture from the rest of the panel was identified. This OEM texture was then applied to the finished molding surfaces to ensure consistent looks with the rest of the interior of the car. 

Then it was time to start making parts! Also, the molding process used an optimized cycle time to ensure perfectly made parts. These parts exceeded the initial demand due to their high-quality fit, feel, and functionality. In short, this product was a great success!