In Parts One and Two, we talked about what types of inspections can be utilized from 3D scan data - both QC applications and NDT/integrity applications. In this post, we will discuss using the scan data in an entirely different way.
Reverse Engineering & Design Applications
It is a common misconception that once we have a scan of a part, it's possible to instantly create a CAD model and drawing and send the information to manufacturing. This is, unfortunately, not true - there is no current solution on the market that offers instant scan-to-CAD modeling, especially if there is a desire to have the part perfected.
Typically, reverse engineering a 3D scanned part requires design intent, which means we add CAD correction to an imperfect part. We force dimensions to be a certain value to conform to standardized measurements, correct manufacturing errors, repair wear or damage on the part, and account for the inaccuracy within the scan data itself. This allows us to create an idealized part to move forward with the manufacturing process.
Most commonly, reverse engineering is completed for the following scenarios:
Remanufacturing unavailable parts (original manufacturer is out of business, the part was customized onsite, lead times of new parts are unfeasible, etc.)
Repair of damaged equipment
Design improvements to existing parts or equipment
Digitization of manufacturing process in a company that does not use CAD software
We have several different options for scan-to-CAD reverse engineering software, each which has been designed to work with large scan data sets and convert to CAD models. Most are compatible with traditional CAD packages, like Geomagic Design X, Geomagic for Solidworks, and Creaform VXmodel. Each software has its own strengths and is suited for different applications and budgets. From these software programs, typically the user will end up with a generic CAD model or a CAD session with an editable feature tree as a deliverable. From here, they may create drawings or send the CAD models to their manufacturers.
Another application in the area of scan-to-CAD modeling is scan-based design. This is when we use accurate and detailed scan data of an object to design new and customized parts to fit together.
Models of the existing part are not necessary in this workflow, since often a designer is not planning on reproducing the existing object. Instead, they will use the scan data as a reference for new design. Mounting locations, interfacing surfaces, design envelopes and clearances, and installation constraints becomes easier to visualize and manipulate when using detailed scan data as a base for design.
While the scan data is an important part of the process for both of these workflows, typically the final deliverable is a generic CAD model or a CAD session.
The Final Question
When choosing a 3D scanning solution, it is important to ask yourself the following question:
WHAT DO YOU REALLY NEED FROM THE 3D SCAN DATA?
The applications for 3D scan data are limitless – it’s just about finding what exactly you need as a deliverable. Scan data, in and of itself, is rarely the end goal. So asking yourself what you really need out of the 3D scan data will help you determine what additional tools you need to use the data effectively.