Is 3D Scanning Right for Your Inspection Needs?

Quality and reliability matter more than ever. In today’s hyper-competitive environment, companies can’t afford to lag behind when it comes to the quality of their products. And management can’t lag behind when it comes to adopting new tools and technologies to ensure quality everywhere. Over the past two decades, 3D scanning has become a crucial tool in many manufacturers’ measurement and inspection arsenals. It’s an effective metrology technique that is trusted for its accuracy, reliability, speed, and ease of use. Its noncontact nature and exceptional flexibility make it ideal for measuring a wide range of parts in a wide range of places. An effective approach to 3D scanning requires matching the right people with the right hardware and the right software to best meet your company’s measurement needs.

A comprehensive 18 page ebook has been produced by 3D Systems to assist in determining if 3D scanning is right for your inspection needs, and if it is, how best to go about implementing the technology in your business. We highlight below an extract. Click here for complete ebook download

Laser Triangulation Scanners
One of the most popular and versatile 3D scan technologies, laser triangulation scanners pass a laser line over the surface of a part, and using straightforward trigonometric concepts, calculate the distance from the sensor to the scanned object’s surface.

Structured Light Scanners
Structured-light 3D scanners project a series of linear patterns onto an object and use sensors to recognize deformations in the patterns that indicate each pixel’s distance from the sensor. These systems are often referred to by their light source, with white light or LED blue light being common approaches.

Medium And Long-Range Scanners
For scanning larger objects such as heavy equipment, aircraft, ships, buildings, or factory floors, there are two primary technologies available: Phase-shift and time-of-flight laser scanners.

Use 3D Scanner to The Best of its Ability

Collecting copious amounts of measurement data is getting easier and easier. Modern 3D scanners collect 500,000 or even 1 million points per second, so you can measure the geometry of your parts with exceptional resolution and fidelity. Reliably taking advantage of all that information requires the right scan-native software. Most 3D measurement software was not built to handle 3D scan data. Software built to use data from stationary or portable CMMs or laser trackers is optimized to work with a small number of discrete measurements that are known to be individually accurate. Working with 3D scan data is very different for a number of reasons. The companies that make these non-scan-native software have done their best to make their unoptimized software architectures work with scan data, but the reality is none of them do it particularly well. To fully exploit the potential that 3D scanning offers, make sure you select 3D scan-native inspection software to ensure everyone who uses it measures confidently and reliably.

Increase Measurement Precision

One of the misconceptions about 3D scanning is that it’s inherently less accurate than contact measurement. All other things being equal, an individual contact measurement will likely exhibit less random error and therefore be more accurate than a single non-contact measurement. But with the right noise filtering, outlier removal, and geometry fitting algorithms, copious amounts of non-contact measurements can yield equally or more precise measurements of the position, shape, and size of features on a part. Look for 3D scanning software that has these scan-specific algorithms – not just standard CMM measurement and fitting algorithms scaled up to work with lots of data, which don’t interpret scan data properly. Additionally, look for software that automatically determines the optimal settings for every scan and doesn’t require users to become experts to attain reliable results.

Display Deviation Color Maps on 3D CAD Models

Imagine looking for your keys in a pitch-black room. Would you rather use a flashlight that can only illuminate a small area of the room at one time, or flip the light switch and see the entire room at once? That’s the difference between
measuring a few dimensions on your part, versus seeing a full deviation color map that compares your scanned part
with a nominal 3D model. It’s extremely helpful to have a color map on top of the measurements called out on a given part. It answers the questions those dimensions bring up. Many 3D measurement software will display a basic color map on top of an imported CAD model. But that’s barely scratching the surface of the analysis you can do using 3D scan data. Look for software that can do more advanced deviation analysis, such as 3D, 2D cross-section, boundary, along curve, silhouette, and virtual edge comparisons.

Use Golden Parts for Comparison and Analysis

Don’t have 3D CAD models to compare your scanned parts to? No problem. High-quality 3D scan-native software will also allow you to create clean nominal reference models from 3D scans of “golden parts” – parts that are perfect or nearly perfect – that you can then compare every other partto. The most advanced software will automatically define features on your scanned nominal so it will behave just like a full CAD model.

Measure Features With GD&T

Many people assume that it’s better to measure basic geometric features using a contact measurement system like a CMM. When you have a limited number of features to measure, that may be true. For more complex parts with dozens or hundreds of individual features, it will almost always be faster to scan and then use software to identify and measure those features. Look for software that can automatically identify features in a 3D scan, filter the data intelligently to remove noise and take reliable, accurate measurements. You’ll speed up your inspections and be able to measure GD&T (Geometric Dimensioning & Tolerancing) on your scanned parts as well.

Don’t Just Find The Problem Fix The Problem

Design, engineering and quality used to be in siloed departments that barely worked together. That era is gone now. Quality is everyone’s responsibility, and when an issue is found with a manufactured part, it’s important that the feedback loop goes all the way back to the design of the part. Today, that means making sure the 3D CAD model of that part is updated to either match the reality of the part as-manufactured (if the part performs within spec) or updated to compensate for process-induced manufacturing errors.

Click here for complete ebook download

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