The 3D printing industry is helping to grow the market for 3D scanners, especially with the introduction of a number of low cost scanners. Are these scanners an alternative to more professional versions for your application?
Leslie Langnau, Managing Editor
How will the introduction of low cost 3D scanners affect your design process? For more than 40 years, 3D scanners were traditionally high-priced tools targeted at measurement/metrology, quality inspection, and reverse engineering applications. While often viewed as on the high side, the price of these units reflects the accuracy, robustness, and capabilities of these devices.
The introduction of lower cost 3D scanners began about two years ago, in 2012, when creative users were looking for something much lower priced than the professional units. These users turned to gamer systems, like the Xbox Kinect, to deliver reasonable 3D scanning data for a 3D printer’s use for around $300.
Today, these less accurate, lower cost, but functional 3D scanners include the Sense from 3D Systems and the MakerBot Digitizer at prices ranging from $400 to $1400. Other middle range functional 3D scanners, such as the Artec and Next Engine units, are available for around $10,000 or less.
With all of the recent introductions, it’s easy to see why industry forecasters predict that the market for 3D scanning should double from about $2.06 billion in 2013 to $4.08 billion by 2018.
“These more consumer oriented scanners may not always produce dimensionally accurate models, though” noted Les Baker, senior application engineer, Faro, “but they produce models that look right, so they are useful for certain other applications, like multimedia, or show and tell. They are opening newer opportunities for the use of scanners.”
Combined with several technical advances, such as more economical data storage for example, 3D scanning has emerged as “the hot new field.”
But choose carefully between the professional and the lower cost versions of 3D scanners. You get what you pay for. “Higher end scanners monitor environmental factors that can alter measurements such as air temperature, humidity, air pressure, which all bend the light beam, such as from a laser, affecting data accuracy,” noted Baker. “Desktop scanners may not notice desk vibration, movement or other factors that affect data accuracy,” … whereas the professional scanners compensate for these factors.
“The key deciding factors for selecting a scanner are accuracy, part size, set up requirements, and needs for robustness,” said Burt Mason, product manager, Hexagon Metrology. “With these lower priced 3D scanners, there is an accuracy threshold. They will create a point cloud, but it is not accurate enough for inspection applications. They have limited accuracy for larger or high accuracy parts and typically lack the robustness for the shop environment.” If your applications involve aerospace or automotive, this limitation is important. And if you are looking to incorporate a 3D scanner into a production process, robustness will be a key factor.
On the other hand, the lower cost scanners now give engineers the opportunity to have one at their desk, opening up application possibilities.
Software pitches in
Two main trends are affecting developers of 3D scanning software to add function, features, and create easier to use products.
1. More non-experienced users are being called upon to operate 3D scanners.
2. The capability limits of lower cost scanners are such that additional functions must be provided by software.
“A lot of scanner development is heading in the direction of making it easy for non-experienced users to operate 3D scanners,” said Mason. “Five years ago, it took a lot of expertise to correctly operate a scanner. Companies now seem to be using unskilled labor to do the scanning task and then have an experienced engineer handle the other tasks involved with scanning, such as fine-tuning the data.
“So the issue is how do I get from the point cloud into usable data,” added Mason, “into polygon models, nurbs surfaces, and so on. These steps are simplified, and allow the not-so-trained user to work with these systems.”
In addition, newer software is taking on many data processing functions computers and CAD programs were called on to do. The professional scanners can generate tens to 100s of Giga- and terabytes of data, straining computer power.
“Until recently, the bottleneck was always the computers,” said Baker. “The amount of data was always running at the limit of what the technology could handle. In recent years, though, computers have been on a development tear in terms of RAM and the number of processors you can have, making it easier to handle all the points high-end scanners can gather. Now the new bottleneck is the CAD program struggling to handle the data. Most scanner acquisition software compensates for this, preprocessing the data so that the CAD program can handle it better.”
Other features of professional scanner software include the ability to adjust for shiny surfaces, noise, and resolution that affect data accuracy. The professional scanner systems handle these needs better than the lower priced scanners.
Are these low cost scanners disappointing some users? According to some vendors, that is happening and is a risk. On the other hand, the next generation of engineers, i.e., the student population, have an opportunity to train with the lower cost scanners, similar to the educational uses of hobby/maker style 3D printers.
Finding the right scanner
When evaluating a 3D scanner, whether a professional one or one more targeted at the consumer market, consider the following:
• What is your application? Are you scanning for quality or rapid prototyping needs, for example?
• What flexibility do you need in terms of applications? Do you need a scanner to handle multiple needs?
• Will you use a test part or the actual part to evaluate accuracy or features?
• Be sure to scan over the evaluation part in multiple directions to see if the unit misses data. Also check for accuracy at specific measurement distances.
• Repeatability is not always a needed feature, even in a manufacturing production application.
• Look at setup time. How long will it take to ensure the scanner is ready to operate and is that time workable for your application need?
• What tasks will be needed to prepare the part for scanning, such as powdering the part to eliminate shine?
• White light is often easier to set up and deliver the needed data, but your application may need laser
• Check with the manufacturer to see how they test for accuracy, especially if the scanner is part of a system.
If you are not ready to add a 3D scanner to your toolbox, check into the various service bureaus that offer scanning. These companies will deliver a range of services, all the way to delivering a product your CAD program can work with immediately. In addition, it gives you an opportunity to look into different types of scanners for the one that best fits your needs.
eQuality Tech Inc.
Faro Technologies Inc.