How To Capture Hole Dimensions When 3D Scanning

By Brian Metzger on

3D scanning is commonly used for quality assurance and inspection. They provide extremely high-precision scans and provide 3D measurements that are among the best in today’s technology offerings. 3D scanners are extremely valuable tools that offer time and money saving benefits, but sometimes the object being scanned can provide some challenges.

In this article, I will be discussing a problem I encountered while trying to capture hole dimensions while trying to 3D scan a circuit breaker housing and how to solve this problem.

Watch the video below to learn how to accurately capture hole dimensions with a 3D scanner.


The Challenge

The most important part of the scan is QA analysis on the location of the four through holes on the part. The problem is picking up the holes well enough in the scan.

capture hole dimensions using 3D scanner

Holes can generally be a challenge with 3D scanning. The way the scanners work, they project a pattern of light onto the surface of the object and read curvature on that pattern with cameras. This process works best on outward facing surfaces. These small diameter holes that are on an oblique angle are difficult to pick up.

3D Scanning as a Quality Assurance Tool >>

The Solution

There are adjustments that can be done to the scanner and software. I could also apply a lot of processing power at the problem. What if I look at this differently?

Instead of trying to change the way that I scan the object, I can try to change the geometry of the part to get the locations. In this case, I am going to use a couple of little wooden dowel pins with the correct diameter inserted into each of the holes.

hole dimensions

Next, I will check the location of those holes from this boss surface that I have added to the geometry. The scan resulted in a much better scan because the dowel pins are a larger, outward facing surface, so it’s easy to capture them accurately. The last step is to alter the CAD model to display bosses where the holes should be. One quick sketch and an extrude feature to add some extra geometry to my model, and I can export to Geomagic Control X, my QA software of choice.

I can now use the Control X software to check the location of the dowel pins very easily. The results show that they are not placed as accurately as I would like them to be. They are not hitting the tolerances that my client has specified. I am now able to report those findings back to my client with high confidence.

Do you have a scanning project that you need help with? Our applications experts have years of experience working with various types of scanners in a wide variety of industries. We would be happy to review your needs and advise how 3D scanning can assist your business.

To learn more about 3D scanning technology stream our webinar “The Advancements of 3D Scanning in Industrial Applications.”