by Noelle Stapinsky
Moving automated 3D inspection technology to the shop floor boosts throughput with faster quality control
The key driver for improved measurement and accuracy for any job shop is pretty simple—everyone wants to make a quality part the first time. And as technology constantly evolves and automation becomes the new norm on the shop floor, the need for real time quality inspection and data feedback has become critical.
Traditional measurement processes, such as using a manual hand gauge or micrometer, are incredibly time consuming and vary in reliability in terms of how a part is measured and the person doing the measurement. Even for shops already using a traditional coordinate measuring machine (CMM), moving the part—whether it’s to an inspection room or just away from the processing machine—means time lost.
The new strategy for many is moving automated inspection technology closer to the manufacturing process and 3D inspection suppliers are noticing the increased demand.
“The benefits would be that you could measure all those parts faster, accurately and consistently. And improvements in reliability mean you’re not rejecting parts or passing parts when you shouldn’t. You’ll have an improved yield in only accepting products you should and that will also drive down your rework because you’ll calibrate your machine tool to deliver parts as they should be,” says David Wick, manager of product management for Zeiss. “Plus, if you’re a small machine shop and you’re selling to a tier one automotive supplier who’s selling to the big three, for example, you have to supply quality reports to your customer. The systems we have enable you to do that.”
Up close and measurable
Peter Detmers, president of Mitutoyo Canada, says there are a variety of 3D inspection technologies available today, including structured light, laser, tactile probing and optical. “Many of these technologies can be used standalone or in conjunction with other components such as a vision system or CMM, or added to a robot for large capacity measurement.”
Just as the shop floor technology has evolved, 3D inspection technology has kept pace with advancements. “One of the biggest changes in the recent past is the emergence of what we call non-contact sensors that use a laser beam or beam of white light to measure the form of an object,” says Wick. “It’s an interesting technology, but what it enables the customer to do is measure uniquely shaped surfaces such as a turbine engine blade or an impeller blade, quickly and accurately.”
Zeiss DotScan is a chromatic white light non-contact sensor that captures a structure’s form. This technology is geared toward sensitive, low-contrast or reflective surfaces, which are difficult to capture with optical sensors.
Another area of technology improvement is the ability to measure surface finish or roughness on complex parts. In April 2018, Zeiss launched Rotos, a roughness sensor, which is easily integrated into CMMs and enables operators to also measure roughness and waviness on the same work piece. “Rotos is integrated into Primso and CenterMax CMMs we make. It uses the same software used for all the other dimensional measurements, the same machine and platform, and it produces the same reports,” says Wick. “It’s a very streamlined process that winds up saving the customer a lot of time, therefore making them more productive.”
Some manufacturing shops need to get their measurement systems even closer by integrating measurement technology into their machine cells. James King, Blum-Novotest’s regional manager in Canada, says that many job shops can’t afford to remove parts from their machine without confirmation that critical dimensions have been machined correctly.
“In some cases the part may be too large to move to a CMM for measurement or the cost of putting it back on the machine for rework will consume profit from the job and time from the machine,” says King. “One of our solutions — Blum FormControl — is a type of measurement performed on the machine. The software allows you to import your part drawing, then point and click on the features you need to inspect, which will generate a probing routine.”
This software will also perform a collision check before sending it to the machine where an inline probe will measure the part. And once the measurement is complete, a digital view of the inspection report is supplied in a PDF version.
“Now you know that you have a good part or you know what needs to be reworked before it comes off the machine,” explains King. “The software is PC based and very intuitive. In most cases it’s used by the operator on the shop floor and they can generate the inspection routines themselves.”
Connectivity equals quality
Many job shops with CMMs or other 3D inspection on the shop floor are using the technology for a variety of solutions, according to Detmers., such as for machine setup “which helps quantify the set up of a machine by confirming feature sizes prior to progressing to higher production. And some use it to qualify production by sideline or inline part inspection.”
The benefits to the manufacturers are certainly broad. Integrating inspection technology with robotics reduces the physical handling of parts. Feedback to machine tools can also be implemented to allow the measuring device to analyze parts and provide data to the machine tool correction software so that offsets can be made before a bad part is produced. “Companies can also take advantage of real time data collection and analysis. Many collect data because they are required to, but the value is in retaining and analyzing that data,” says Detmers. “For instance, tool offsetting can only be done to a point. At some stage the tool needs to be replaced. But if you had measurement data combined with information of when a tool was changed or broken, perhaps over time you could see a correlation between changes in size and tools wearing. That could be used to evaluate tool life.”
Detmers continues, “or maybe you have two machines running the same job. What if one of the machines was underperforming on part quality or throughput. Analyzing that data can identify these nuances and help you understand how to correct the differences.”
According to King, it’s all too common on the high production side to have the inspection without communication to the machine tool. And when a defect is found there are a number of parts that need to be sorted and inspected. “The other side is when the larger, more expensive or one-off parts have to be moved for inspection and then back to the machine for costly rework.”
That is why Blum has been focused on collecting data for manufacturing and how to use that data to make true autonomous decisions to maintain quality and process stability. “One way we are already doing this is with AutoComp,” says King. “This is not a Blum product, but we have a close partnership with Caron Engineering, the manufacturer, and we distribute it exclusively here in Canada.
AutoComp is software that takes data from any type of gauging —digital caliper, custom gauge, spindle probes or CMM—and communicates back to the control to make automated offsets as required. “Non-automated cells shouldn’t be without the ability to communicate back to the control when tools are wearing and sizes are changing,” adds King.
As more small to large job shops invest in automation and technology, the market for entry-level inspection solutions is on the rise.
In the last two years, Zeiss has introduced an entirely new optical system called O-Inspect 322, and DuraMax, a tactile system, both of which are specifically aimed at the small to medium sized shops.
The O-Inspect 322 is a 3D inspection machine that combines a non-contact optical sensor for part geometries that are hard to access, and a touch sensor. “The operator has a choice and it’s all programmable by the same software that’s very user friendly,” says Wick. “The DuraMax is a tactile tabletop machine. You can run it on a bench top, put it in an automation cell or connect it to a robot so it can automatically load or unload the part.”
Wick adds, “we see the market for more entry level, budget conscious machines every year. And they’re not going to the big guys, but companies well down the supply chain that need to be more productive.”
In the manufacturing world, everyone wants to go faster. Order runs and lead times are shorter, making the demand for first part good part even more imperative. The data collected by 3D inspection technology can take the overall operational view to the next level and help companies fully understand their processes, where challenges exist, and identify areas of improvement, which will lead to improved throughput and cost savings. SMT
