The Reverse Engineering Workflow
Reverse engineering is important when you want to create new parts that reference or incorporate older designs, where the original CAD design isn’t accessible.
For example, you can create replacement parts that match the original design of damaged existing pieces, or use reverse engineering processes to integrate complex surfaces from existing objects into 3D printable jigs, which are useful when modifying mass manufactured and handcrafted products.
To demonstrate the basic steps in a reverse engineering workflow, let's take a look at the process for creating an assembly jig for an aftermarket digital gauge that fits onto the air vent of a Volkswagen Golf.
The Right Tools for Reverse Engineering
The first step to start reverse engineering parts is to find the 3D scanner that is best for your needs. Read about which 3D scanners complement high accuracy 3D printing in our white paper:
-1. Prepare the Object for Scanning
Spray coat the object with a temporary matte powder to improve scan accuracy. Even slightly glossy surfaces tend to degrade scan quality, while reflective and transparent surfaces cannot be scanned at all without a matte coating.
-2. 3D Scan the Object
Maxxeshop use a high accuracy 3D scanner to capture the important sections of the part. Our tabletop structure light scanners are the right tools for the job, with accuracy of ±100 or better.
-3. Refine the Mesh
Our scanners produce extremely large mesh files, which will make our reverse ngineered parts extremly accurate.
Maxxeshop's scanner software repairs small gaps and simplifies the scan, making the data more manageable in CAD ready for coversion to a 3d printable model.
4. Import the Mesh to CAD
Maxxeshop then import the mesh into CAD software equipped with reverse engineering tools with powerful tools for resurfacing complex, organic shapes.
5. Extract Important Surfaces
Maxxeshop the extract the shape of the scan in order to create a solid model that is editable with CAD tools allowing production of a 3D printable file.
7. 3D Print the New Design
Printing a jig on Maxxeshop's printers gives you a high degree of accuracy comparable to the output of engineering-grade 3D scanners.
Once these steps are complete, the 3D printed model is ready to use to assemble the new item into the OEM part.
From Physical to Digital: Meshes and Solids
One of the biggest challenges people encounter when converting physical objects to digital is a major incompatibility between two different types of 3D models: meshes and solids.
Meshes are the main output of all 3D scanners, and the format commonly understood by 3D printers (STLs). A mesh represents the surface of a shape with a large number of triangles, connected edge to edge. Mesh models don’t contain any information about the object, besides the position of the triangles that define the shape.
On the other hand, our engineers are trained to work with solid models. Solid models hold information about how an object is designed, and this information is explicitly encoded into the model as features in a ‘stack’ of logical steps. In solid CAD, it’s possible to change the dimensions for a single feature, and the rest of the model will update to accommodate the change.
Since meshes lack information about the construction of the object, the ways you can alter a mesh model are limited—CAD software like Solidworks and Onshape can’t directly modify meshes. If you need to make major modifications to the underlying design of a scanned part, the mesh needs to be converted to a solid CAD drawing: this process is reverse engineering.