3D scanning and reverse engineering: a new tool for an old task
Merriam-Webster defines reverse engineering as the process of disassembling and examining a product or device to discover the concepts involved in its manufacture, usually with the goal of producing something similar.
This is no new concept, dating back to ancient times when reverse engineering was primarily used in wartime to unravel the technological secrets of opponents. A somewhat recent and notorious example is the Enigma machine, which the Allies figured out during World War II.
Nowadays, reverse engineering is more commonly associated with the process of converting a physical object’s geometry into a digital 3D model, taking the reverse direction of a typical design workflow. But this “modern” kind of reverse engineering is only possible with relatively new technologies such as 3D scanning.
Before 3D scanning, traditional reverse engineering involved extremely time-consuming, manual tasks and tools like calipers. This severely restricted the range of reverse engineering applications, considering the high-quality standards of parts and products in today’s market and the aggregated costs involved.
3D scanning can efficiently capture the geometry of even the most complex parts in an extraordinarily quick and precise manner. A large docking pump was recently captured in just 20 minutes, for example, with the help of laser 3D scanning.
This technology has enabled the use of reverse engineering in situations beyond simple benchmarking and part reproduction, as we explore in the next section.
Main applications for 3D scanning and reverse engineering
Reverse engineering with 3D scanning offers many possibilities for product development and manufacturing. Overall, the different uses of reverse engineering can be divided into three major applications: to replicate parts, to create variations of existing parts, or to develop entirely new parts based on an existing environment or object.
1.Recreate and replicate parts
One of the most popular uses for 3D scanners is recreating damaged or worn-out parts that are unavailable from the original supplier or lack proper documentation. This is a common problem when working with old machinery or vintage vehicles, and it’s always challenging to do with manual reverse engineering tools like calipers.
However, with a good 3D scanner and the proper software, it can become a straightforward task. Katsuya Tanabiki, for example, shared his process of reverse engineering a shield notch on an old motorcycle helmet. The helmet featured two shield notches, but one was broken, and it was too difficult to obtain a replacement notch. This tiny part was 3D scanned with an EinScan Pro 2X in Fixed Mode, and later 3D printed.
But the actual fabrication of the part is not always the end goal. The aerospace and automotive industries, among others, knowingly use reverse engineering to digitize components and create digital inventories of legacy parts. These digitized components are known as “digital twins”.
Here, 3D scanning is indispensable considering the intricacy of these parts and the strict dimensional requirements and standards they must meet. Take, for example, this small turbine reverse-engineered by Print3DD. The distinguishing geometry of its blades would be impossible to reproduce accurately without 3D scanning.
2.Improve existing parts
Another goal of reverse engineering is to use digitized parts to create new and improved variants instead of merely reproducing them.
This method can significantly reduce the time and costs of creating parts from scratch and also ensures a perfect fit for components belonging to larger assemblies.
Taiwanese company Kiden Design has illustrated the reverse engineering process of optimizing a pipe using 3D scanning, CAD, and 3D printing. The EinScan Pro HD 3D scanner, used in Handheld mode, captured the irregular geometry of the pipe on two opposite sides that were stitched together later in software. Thanks to the accurate 3D model obtained, the geometry could be easily optimized in CAD.
Another good example of reverse engineering being used to create new versions of physical objects is the customization of furniture parts with 3D scanning and CNC wood carving by Voxel 3D. In this project, the carved ornaments of one piece of furniture were digitized with 3D scanning and integrated into different parts.
3.Create entirely new parts
The arrival of 3D scanning has enabled yet another application for reverse engineering, one that utilizes digitized parts as a reference to create entirely new parts.
This procedure is usually employed when a tight fit is required on an existing part that is too complex or has an irregular interface.
To illustrate this, let’s look at a use case from the Fuller Moto automotive customization shop. Bryan Fuller and his team used the EinScan Pro 2X Plus to 3D scan the entire footwell of a 1967 Lincoln Continental. The digitized region was used as a reference to design a new kick panel, and the precise 3D model of the footwell made it possible for the new part to fit flawlessly in the customized car.
This particular technique is also commonly practiced by medical professionals since body parts are unique and challenging to accurately replicate using manual methods. Here, 3D scanning once again has proven to be an efficient tool for digitizing human parts and surfaces.
Earmolds, for example, are patient-specific parts that help conduct sound from the hearing aids to the ear canal. Servicing or creating new earmolds from scratch can take several weeks, during which patients experience hearing problems without them.
However, thanks to reverse engineering methods with 3D scanning and 3D printing, the Hearing Beyond Audiology Clinic in Toronto can produce temporary earmolds in just one day. The temporary accessory allows patients to keep their hearing while waiting for the earmolds to be produced or serviced in other facilities.
What makes for a good reverse engineering job?
The use cases above clearly demonstrate the central role of 3D scanning in reverse engineering. It comes as no surprise that the effectiveness and accuracy of data captured by 3D scanning are crucial for a successful reverse engineering process.
Yet, the software tools used for processing the data and working with the 3D models are also essential for achieving the desired results in reverse engineering.
To understand the importance of good data and adequate software, let’s go over the main stages of reverse engineering with 3D scanning.
The very first step in any reverse engineering process is data acquisition. Regardless of the method, proper planning and preparation can make the difference between good and poor data.
With 3D scanning, this involves selecting the correct device for the job, including the proper configuration (handheld or stationary) and accessories such as turntables, fixtures, and calibration panels. Correct calibration of the device is also vital to acquire quality data.
The regions or parts to be digitized usually demand some kind of preparation. Besides a good cleaning, some 3D scanning devices also require the use of markers or even special coatings on reflective surfaces.
One should also consider the ambient conditions before starting the digitization process. A controlled environment (e.g. indoors, without direct sunlight, a cleared tabletop, …) is always preferred to reduce noise in the data, but that’s not always possible.
All the factors above will contribute to proper data collection, which will in turn determine how quickly and easily the data can be processed next.
The next step in a reverse engineering process relates to post-processing the acquired data, or “point cloud”. Here, the point cloud is processed by software tools – like EinScan software – resulting in a 3D mesh representation of the digitized object.
In any case, the 3D model in this initial stage usually requires some refinement like removing unwanted captured data, repairing surfaces, and filling gaps.
Here we can understand why the data acquisition step is so important: the better the data quality, the less post-processing and repairing will be needed.
The post-processing step is also when reference entities are assigned to the 3D model, a procedure that should expedite the next stage of the reverse engineering process.
The final step in a reverse engineering process is to convert the mesh representation of the physical object into a solid 3D model.
As accurate as the mesh model can be, it is inadequate for most reverse engineering applications that require additional handling like fixing any physical damage, creating variations, or designing new parts altogether.
In this stage, the refined mesh model from the previous step works as an exact reference model for recreating the model using parametric CAD tools.
Although theoretically any general-purpose CAD program could handle this, specially purposed software geared towards reverse engineering can make the process much easier and yield much better results too.
An appropriate CAD software for reverse engineering can also compare the digitized model to the parametric one, allowing users to check for geometrical and dimensional differences.
Reverse engineering has come a long way from the militaristic applications it once had in the past. 3D scanning technologies have broadened the range of industrial applications for reverse engineering, benefiting both businesses and consumers.
Nonetheless, the quality of the captured data is crucial to obtain good results in reverse engineering. The choice of the 3D scanning device, as well as its capabilities and functions, play a central role in the success of the entire process.
Though often overlooked or underestimated, the software used in the later stages of reverse engineering also bears great importance. Specific built-in tools for the job can make a big difference in a well-executed reverse engineering process.