Why We Used Three Different 3D Scanners on One Reverse Engineering Project

A customer recently contacted EMS3D with a challenging reverse engineering project. They needed to reproduce a large portable power generation trailer, but the original trailer was no longer available from the original source. To manufacture new units through a different vendor, the customer needed accurate three-dimensional data and a detailed CAD model of the existing trailer.

At first glance, this may sound like a straightforward large-part 3D scanning project. In reality, the trailer included an unusually wide range of geometry. We had large exterior surfaces and structural features, but we also had rear doors, latches, access panels, power connection points, conduit, switches, control boxes, brackets, floor holes, and other small features. Some areas were open and easy to reach. Others were confined, obstructed, or located inside the trailer.

Trying to capture everything with one 3D scanner would have created a compromise. A long-range scanner could efficiently capture the overall trailer, but it would not provide the same fine detail as a handheld scanner. A high-resolution handheld scanner could capture the smaller features, but using it to scan every square inch of a structure this large would take much longer and generate more data than necessary.

Our answer was to use three different 3D scanning technologies, assigning each system to the part of the job it handled best. This let us move quickly without giving up the accuracy or detail required for the final CAD model.

For the large-scale geometry, we used a Surphaser 100HSX. For medium-range geometry and detailed areas, we used a Creaform HandySCAN MAX Elite. For the smallest features and areas with limited access, we used a Creaform HandySCAN EVO.

These scanners do not compete for the exact same role. They complement one another. Together, the three systems created a complete digital representation that would have been difficult to produce as efficiently with any one scanner alone.

We began with the Surphaser 100HSX to capture the overall exterior and interior structure. For the upper surfaces, we placed the scanner on a scissor lift so we could scan the roof and upper sides from the necessary positions. We then moved to ground level to capture the lower sides and underside areas included in the project scope.

We completed approximately 16 exterior scan positions. Spherical targets were placed throughout the work area and captured from multiple scanner locations. Those common targets gave us reliable reference points for aligning the individual scans into one coordinated data set.

We used the same basic approach to connect the interior and exterior data. With the rear and side doors open, spheres positioned inside the trailer were visible from selected exterior scan positions. We then moved the Surphaser inside and completed additional scans from several locations. Because the same targets appeared in overlapping scans, we could accurately register the interior to the exterior.

After the large-scale geometry was established, we moved to the HandySCAN MAX Elite. This is where we began concentrating on the features that required substantially more definition than the long-range scan was intended to provide.

On the exterior, we scanned areas such as the rear doors, handles, locks, latches, access panels, and power connection points. Inside the trailer, we captured conduit, switches, control boxes, bus bars, brackets, floor hole locations, and other components that had to be represented in the CAD model.

One important advantage of the MAX Elite is its ability to work with multiple scanning volumes. We could adjust the scanning volume and resolution for a larger area or a smaller feature while remaining in the same scan file. That flexibility made it possible to cover substantial portions of the trailer and then move closer to capture more detailed geometry where needed.

The handheld workflow also offered a major practical advantage inside the trailer. The Surphaser remains stationary during each scan, so complete coverage requires a series of scanner setups. With the HandySCAN, the operator can move around the object and see the coverage develop while scanning. This meant fewer setups, faster data capture, and better access around components in a crowded interior.

We could have collected denser long-range data, and it still would not have matched the handheld scanner on these details.

When the Surphaser and MAX Elite data are viewed side by side, the reason for using both systems is easy to see. The Surphaser efficiently captured the general form. The MAX Elite showed the finer geometry needed to model the handles, connectors, latches, and similar components — and it was a far more efficient way to complete the job.

The final scanning stage focused on the smallest and most detailed features. For these areas, we used the HandySCAN EVO. Its higher detail capability and compact handheld access made it well suited for restricted spaces and intricate geometry.

The EVO allowed us to reach areas where scanner access and line of sight were limited. Its onboard display let the operator monitor scan coverage in real time, making it easier to identify missing areas before leaving the job site. The built-in camera also allowed us to document the work with photographs that could be referenced later during CAD modeling.

We did not use the EVO everywhere. That would have defeated the purpose of the multi-scanner strategy. We used it selectively where the project actually benefited from the additional resolution, access, or documentation. This is an important part of planning any 3D scanning project: more resolution is not automatically better if it adds time and data without improving the final deliverable.

The combined project produced a substantial amount of information. Across the different scan files, the final data included approximately 381 million triangles and more than 125 gigabytes of raw scan data. After exporting the various data sets to STL format, the combined files totaled about 25 gigabytes.

Although that is a large amount of data for many projects, it is not unusual in our work. When we scan very large aircraft, industrial equipment, facilities, or other complex assemblies, data sets can become considerably larger. The key is not simply collecting as much information as possible. The key is organizing the information so it remains useful throughout inspection, reverse engineering, and CAD modeling.

We color-coded the scan data by technology during review: the Surphaser data in blue, the HandySCAN MAX Elite data in green, and the HandySCAN EVO data in yellow. All data sets were aligned into the same coordinate system, but we generally kept them as separate scan files rather than merging everything into one mesh.

Keeping the files separate gave our designers better control. When modeling a broad exterior panel, they could reference the Surphaser data. When building a latch, connector, or detailed interior component, they could turn to the MAX Elite or EVO data. This reduced screen clutter and allowed the designer to use the most appropriate source for each feature.

A point that we regularly explain to customers is that 3D scan data is not the same thing as CAD data. A scanner records the physical shape of an object and produces a point cloud or polygon mesh. That data can be measured, inspected, and used as a reference, but it does not automatically become a clean, organized, manufacturing-ready CAD assembly.

Scan data records what exists. CAD data is something an engineer builds from it.

For this project, we used the registered scan data as the foundation for building the CAD model. Before modeling began, we had a detailed discussion with the customer to determine which parts of the trailer mattered, what level of detail was required, and which areas did not need to be recreated. The project focused on the enclosure mounted on the trailer rather than modeling the complete running gear underneath it.

Our designers then created the CAD geometry feature by feature. The model included the major enclosure surfaces along with the key doors, conduit, lights, brackets, controls, connection points, and other items required by the customer. This is skilled engineering work, not an automatic conversion. Depending on the size of the object and the level of detail requested, converting 3D scan data into usable CAD can take weeks or even months.

Defining the required level of detail early is one of the best ways to control the schedule and cost of a reverse engineering project. Modeling every screw, wire, and surface imperfection may not provide any manufacturing value. A well-planned scope concentrates the effort on the geometry needed to reproduce, modify, interface with, or document the product.

After the CAD model was complete, we also produced renderings to help visualize the finished trailer. Rendering software can apply colors, materials, textures, and logos to the CAD model. Components can also be separated so doors open, panels move, and an animation demonstrates how the finished unit will operate.

These renderings are more than presentation graphics. They give the customer and prospective manufacturing vendors a clear picture of the intended result before fabrication begins. They can help communicate design intent, reveal misunderstandings, and support review discussions among people who may not work with raw scan data or engineering CAD every day.

This project is a good example of why the best 3D scanning solution is not always a single piece of equipment. Large objects with both broad surfaces and intricate features often require different tools at different stages.

The Surphaser 100HSX captured the overall trailer efficiently and established the master coordinate system. The HandySCAN MAX Elite added detailed handheld coverage across exterior and interior components. The HandySCAN EVO captured fine geometry and difficult-to-reach areas. By matching each scanner to the work it performs best, we balanced speed, accuracy, access, resolution, and data volume without compromising the final CAD deliverable.