The emergence of additive manufacturing has excited many engineers; one of its many benefits is the freedom to go where traditional manufacturing simply could not. Much of the buzz around additive manufacturing right now is due to a dramatic decrease in production times even as the demand for customized products accelerates.
But there’s an elephant in the room that no one’s addressing: How are you qualifying your additive manufacturing parts? There’s a reason that you chose to use additive manufacturing, and it’s the same reason that prevents you from using traditional inspection methods.
There are a number of challenges that we face when qualifying additive manufacturing parts. Strict regulations, pressure to find a measurement solution, time, and budget are all considerations for manufacturers.
Industries such as medical device, aerospace, defense, and automotive are particularly sensitive to how their parts are validated due to their highly regulated need for safety. There are ways in which these industries are expected to approach their validation tasks, and they’re not going to be discarded simply because it is inconvenient to the 3D printing industry.
Traditional testing methods, such as CMM, are quite restricted for parts made with additive manufacturing, using points in accordance to the touch probes. You need to be able to inspect the parts in a non-destructive way, and this puts you between a rock and a hard place. CMMs have been used for decades, the technology is entrenched in many industries and is a required component in the manufacturing acceptance criteria.
Customers are pushing us for faster and faster turn times. Traditional measurement methods just aren’t good enough; the process needs to be more comprehensive and faster. Engineers find themselves chasing failure with the process of elimination. Is the defect part A or part B? Is it the Design? Is the tolerance too open? How accurate is the machine producing the part? Weeks and months of time along with a lot of money can be spent trying to identify a problem. It’s a costly process that can be minimized.
X ray is expensive, but an option.
Cutting parts is destructive, but an option.
There is a cost-effective, non-destructive, and minimally intrusive option to all of the above…
CT Scanning allows manufacturers to qualify their part in a non-destructive way where no other form of inspection can. Precision parts with small, complex, and fine geometry from benefit especially from this technology, since they are very difficult to measure using even the most advanced laser-based scanning or CMM. This is a quick and accurate way to validate the internal geometry of additively manufactured parts in 3D without applying any external forces or pressure that may alter or warp them. CT scanning also aids manufacturing projects that require 100% validation of high value printed parts through production. Accuracies can reach micron levels (or better).
Here we have a sample part that we had made at a local 3D printing company. As you can see, the complexity of this part doesn’t allow for traditional inspection methods. How can we qualify the internal features without destroying the part? The sales representative told us that the accuracy of this particular machine+/-.005. Sounds pretty great. But who’s validating the machine? Who’s proving this .005? Like CNC machines, for instance, there is no industry standard for proving or qualifying them. We’re left to trust the manufacturers and printers to tell us.
Using the sanitized digital representation of the part, a parametric or organic model can be built with extreme accuracy. Below is the design of the part.
It’s important to note that all scanning platforms – regardless of capture technology – output a point cloud of data.
Rather than use hand tools, point-to-point measurements, 3D scans capture the original part’s geometry. Saving an incredible amount of time, with higher accuracy. Specifications on this machine are .0002 for resolution and accuracy. These pieces of equipment can start around $500,000 dollars, and can easily go up to millions. Usually, this is specific to the size of the chamber, accuracy, and power.
To qualify your part, we’re going to overlay or best fit the data to the CAD. We do this by either a datum alignment or best fit. Once these are overlaid we do a measurement from data to CAD and to display deviations. So what you’re seeing in color is deviation from nominal. Anything that isn’t green doesn’t match the CAD. Areas in cool colors such as blue and pink are negative or less material. Areas that are yellow or red – warm colors – are positive material. Cost always depends on the size and complexity of the part, along with what chamber it fits in. But in comparison to the multiple hours, weeks and months of trying to find the problem the old way, the cost is minimal. Time is money.
In sum, the reason that this part is not a candidate for traditional manufacturing methods is the same reason is that it is not a candidate for traditional inspection methods, but it is just as vulnerable for failure. It’s a common misconception that parts made by 3D printers don’t need to be checked. That these parts will be made perfectly and within the stated accuracy of the machine. But there are no ANSI standards to measure the accuracy of your equipment. So you’re left to trust the 3D printer that what they say is accurate, is.
However, If you seek the right inspection vendor, industrial CT scanning can qualify additive manufactured parts quickly while reducing inspection and production costs. In addition, you won’t be left having to deal with the process of elimination when your prototype doesn’t function, saving you time and money while getting you to market faster; enabling you to stay competitive.
Our focus and priority is to provide high quality dimensional inspection, advanced 3D scanning, modeling analysis, and geometry re-creation services that saves time and is cost effective for manufacturers. Our highly trained professionals can promptly scan and your additive manufacturing parts during or after the course of the development of your product.
Our proficiencies are structured to personally assist you from development into full production. We will personalize your project to accurately and precisely suit your needs. We pride ourselves on our quality service and there is no doubt that your manufacturing process will greatly benefit by more rapid and cost effective production results.
Behind the scenes, The QC Group has developed a rapid-response system that will transform expectations for speed of response and quote turnaround. Online requests for quotes are responded to within 5 minutes of submission, quotes in hand within 2 hours. Request yours at qcgroup.com/rfq.