The Technology of 3D Scanning
3D scanning is a relatively new technology, but one that is rapidly becoming very popular. With handheld 3D scanners costing less than $500 it’s no longer necessary to spend huge sums of money on 3D scanners. The 3D scanner market has grown in proportion to the 3D printing industry and this growth has fueled the development of more low-cost 3D scanners. So, what are 3D scanners used for and how does this change the basic design process?
One of the most efficient ways to generate a CAD model for reverse engineering is by using a 3D scanner. This is particularly true if the physical part that you’re reverse engineering has a complex shape. Traditional measurement techniques are difficult to employ with irregularly shaped objects, but 3D scanning makes it much more efficient…not necessarily easy, but definitely efficient.
What You Need to Know
There are some “tricks” to 3D scanning that it’s helpful to know, starting with the evaluation of the scanner itself to determine which one is best for the kinds of jobs you’ll be doing.
Therefore you should consider the following:
What application do you need the 3D scanner for?
Is high quality of the scan necessary, for rapid prototyping needs, for example?
Will you be doing one type of scanning, or do you need a scanner that can handle many different applications?
Will you use a test part or the actual part to evaluate accuracy or features?
Do a trial run with the scanner by scanning over an evaluation part in multiple directions to see if the unit misses data.
Check for accuracy of the scan at specific measurement distances.
How long does scanner set-up take? Will the set-up requirements cause problems for the applications you need?
Do you need to prepare the part for scanning, by powdering the part to eliminate shine, for instance?
Do you need a white light scanner or a laser scanner? White light is often easier to set up and deliver the needed data, but your application may need laser light.
Find out how the manufacturer measures their scanner accuracy so that you can ensure that the scanner is sufficiently accurate for your applications.
Remember that some of the lower cost consumer-oriented scanners may not always produce dimensionally accurate models, so cost should not be the primary consideration unless accuracy is not important. The lower cost scanners do produce models that look right, so they have their place when cost is a larger consideration than absolute accuracy.
Consider a 3D Scanning Service
If you’re not sure which scanner your need or you’re not ready to commit to the purchase of a high accuracy scanner, then we recommend checking with a CAD service bureau that offers 3D scanning. An advantage of using a CAD service bureau is that they generally offer a wide range of CAD-related services, in addition to the 3D Scanning. Most can use the point cloud or mesh model achieved by scanning to convert into your CAD program so that you receive a file that you can begin to work with immediately.
Another advantage to using a service bureau initially is so that you have an opportunity to become familiar with the output from the various 3D scanners. This can help you to home in on the right scanner for your applications when you’re ready to purchase.