You might not believe it, but I’ve been to Jay Leno’s garage. It’s beautiful, classic cars as far as the eye can see.
One of the biggest problems that Mr. Leno and his motorhead cohorts face is needing a discontinued part. So how do you fix a car when you can’t order the part?
The answer is reverse engineering, the action of recreating an existing design to replicate or replace parts that are impossible, or hard, to obtain any other way. It is generally used to fix legacy equipment or help engineers create designs to support third-party products.
The basic process is to replicate the part digitally — typically in computer-aided design (CAD) software. The digital geometry is created by hand or using scan-to-CAD technology. Once the geometry is recreated, the engineer can build the part using traditional or additive manufacturing methods.
Replicating Lost Manufacturing Methods Using Scan-to-CAD Technology
Reverse engineering is like being an archaeologist. They discover a part whose manufacturing process is unknown or lost to history. They then study the part to understand:
- How it works
- How it’s used
- How to create replicas
During a dig, an archaeologist might find an ancient machine. They can then recreate parts of that machine, so it looks complete in a museum display.
In the engineering world, it works in a similar way. The engineer may find a machine that is currently on the market or decades old.
If the machine is broken and the original manufacturer is out of business, the engineer may need to replicate a part to get the machine running again.
If they need to design parts to tweak the functionality of the original product, then they will need to recreate the original product to test their new designs.
Is Reverse Engineering Illegal?
The legality of reverse engineering is quite situational. Therefore, I suggest contacting a lawyer before recreating any product.
The general idea is to keep legacy equipment running when a supplier no longer exists. If you’re keeping your property in working order, then you are typically okay.
If you are planning on selling the parts, then that could get into some grey, or even black market, areas. This could be likened to rebranding or mimicking an existing product — known counterfeiting techniques.
However, if you are recreating a part to build an add-on for customers of the original product, then you are probably okay. This would be like recreating a cell phone’s shell to design and test a product that mounts phones to a car’s dashboard.
Legality tends to get complex when you need parts from a company that still exists but doesn’t support the product anymore. In situations like this, contacting a lawyer is a great idea.
How to Reverse Engineer a Part Using Scan-to-CAD Technology
Your first step is to scan the part. The 3D scanner will take measurements of the part in the form of a point cloud. You can think of a point cloud as a series of dots on a Cartesian plane. The scanner's software will then transfer the point cloud into an STL file.
The 3D scanner can be as simple as a phone camera or as complex as a laser scanner on a robotic arm. The better the scanner, the more detailed the point cloud.
To transform the STL file into a watertight 3D model, engineers can use CAD software like ANSYS Discovery SpaceClaim.
Bad scan data is common in the engineering world, so it’s best to have access to tools that can accommodate incomplete information in the STL file. SpaceClaim has STL repair tools that can fill in patches, holes and missing faces. It can then blend these additions into the remaining geometry.
Once a watertight CAD geometry is created, engineers can build the part using traditional additive or subtractive manufacturing processes.
To find out more about scan-to-CAD technology, read up on the reverse engineering functionality of ANSYS Discovery SpaceClaim.