Micromachining is machining remarkably small components with a tool that has a diameter smaller than 0.015" and no more than a few-tenths tolerance. Micro tools can create very small, complex parts. It takes a specific machine with sufficient spindle speed and high-quality cutting tools to produce the consistency and strength to run at high speeds. Micro tools can be as small as 0.001" in diameter to achieve the high precision and intricate detail required.
2) Micromachining’s benefits
Micromachining allows reliable, repeatable production of small and intricate components with extremely tight tolerances. Micromachining is ideal for machining complex prototypes and components with micro features in ceramics, plastics, and metals. Applying high-quality micro tools to machines with high spindle speeds or Swiss-type lathes can create cleaner cuts, more precise dimensions, and tighter tolerances. Adding high-quality micro tools to your precision machining application provides the opportunity to produce more distinct components.
3) Micro drilling
Drilling holes smaller than 3mm in diameter requires an extremely sensitive machine with a precise spindle and very low runout. Precision tool holders, typically hand clamped to avoid positioning errors that can occur with an automatic tool change system, will benefit the accuracy of your micro drilling operations. Ultra-fine coolant channels through the body of these tools to the cutting edges allow optimal operating temperature. The tools’ aluminum titanium nitride coating counteracts wear and increases overall tool life. With drills of this size, it’s important to pay attention to wear indicators. Because of the low tool material volume, heat absorption is minimal. Therefore, the price for overloading the tool beyond its predetermined recommendations will be paid in total tool failure.
4) Trochoidal milling with micro tools
Trochoidal milling uses a circular, or trochoidal, tool path. The technique can increase tool life, reduce machining cycle times, and use fewer tools for a job. However, it is crucial to have a precision machine and optimal software capable of dynamic speeds and feeds to avoid critical tool failure. While micro tools can benefit from trochoidal milling, the risk of tool breakage must be carefully considered. Although trochoidal milling can increase your machining efficiency in many applications, it is vital the micro tool used is high quality.
5) Micro tools, macro demand
Demand for smaller and more intricate machined components increases as more industries transition to smaller, more complex components. Micromachining will become vitally important to a precision manufacturing company’s work. To meet this demand, Kyocera SGS Precision Tools has increased production of high-quality micro tools, expanding its line of more than 4,000 new micro tool items to keep up with growing industry demands.
Equiped with an Erowa Robot 80, a sinker EDM machine and mill perform automated electrode changing.
For aerospace manufacturers, electrical discharge machining (EDM) has long been the answer to achieving high levels of accuracy and precision. The industry has relied on this technology for various parts, especially ones exposed to high temperatures and stresses. Some producers turned away from early EDM equipment because of damaged surfaces, but continued development has resulted in more stable, predictable processes. Among these improvements are automation components. Robots, handling systems, and sensors provide real-time feedback, greater repeatability, and improved quality.
In the following Q&A, Mike Bystrek, national wire EDM product manager at MC Machinery Systems, discusses other advantages of EDM automation, available tools, and considerations for implementation.
Vent holes being performed on the Sinker EDM.
Aerospace Manufacturing & Design (AM&D): What benefits does automation offer in EDM machining?
Mike Bystrek (MB): It comes down to knowing how many parts you really need to produce and helps avoid any guess work, keeping work costs under control. For example, an Erowa Robot Compact 80 can be implemented on a sinker EDM to perform automated electrode changing and it changes out the parts as well. So, the good long-term solution is it improves productivity and reduces overall cost.
The biggest advantage to automation is increasing your productivity while reducing lead times. Once a process is proven and automated, it provides repeatable results every time. This ultimately reduces your labor costs, increases part quality, and provides profitability.
AM&D: What smart tools are available on MC Machinery’s wire and sinker EDM machines?
MB: On both the wire and sinker we have an artificial intelligence (AI) system that allows the operator to enter/answer some simple questions on the control, allowing the machine to take over. The system uses real-time condition monitoring within the burn and directly modifies specific parameters for a stable cut that produces optimal results. Because the AI technology analyzes this data, it can reduce overall electrode wear and cost.
In today’s workforce, the older generation of toolmakers in the shop are retiring, bringing in younger people, which is great. But sometimes that experience doesn’t transfer over. So this experience or knowledge we’re building directly into our machines allows operators at all levels to produce quality results.
AM&D: What are some challenges to implementing a wire or sinker EDM in an aerospace facility?
MB: Before you fully automate a process, you must prove that process out. You need to make sure that you’re able to get the part, put the part in the machine repeatably on some tooling, cut the part, and make sure you get the same results. Once that whole process has been proven, I think then you can move on to automating where you can run something like that 24/7. Sometimes people skip the basic steps and try to jump right into implementation, but then miss some of the obvious things.
The rotary table is using an automatic chuck.
AM&D: Why is automating EDM important now?
MB: In this industry, whether it’s aerospace, tool and die, or any kind of manufacturing industry, they’re still on a hunt for skilled professionals to do a lot of this work. Having skilled people set up something like this and allow the customer to automate it would enable them to function at a much lower overhead, making them more profitable. And analyzing to determine if results would lead to reduced overall turnaround time or increased productivity or product prove-out would probably be the first thing I would consider for automation.
It also comes down to dollars and cents. Do you really want to pay somebody X number of dollars to stay in there, pull a part, and take it out? Everybody’s worried about them taking their jobs, but I think that would allow a company to be profitable and perhaps open more doors to people to train them in other areas. That’s the way they should be looking at it. By allowing that, productivity increases and your shop will be much more profitable.
It’s important that we achieve a greater acceptance of EDM and the smart tools and controls that can be incorporated. It’s the optimal way to produce a cheaper part more quickly.
About the author: Michelle Jacobson is the assistant editor of AM&D. She can be reached at mjacobson@gie.net or 216.393.0323.
Job shop automation for high-mix manufacturing
In collaboration with ProCobots, Hurco has developed a streamlined automation package for high-mix manufacturing to make job shop automation practical, providing automation packages that are flexible, easy to program, and easy to move to other Hurco machines without requiring an integrator to make a change.
The Automation Manager control feature seamlessly integrates automation to CNC machines. It includes a setup wizard, job and queue progress bars, a graphical interface between the collaborative robot (cobot) and the CNC machine to facilitate an easy setup process for each job, run multiple jobs sequentially, and load and save job sets.
The Smart Manufacturing Platform seamlessly connects industrial assets and business systems to collect data and provide real-time data collection and monitoring from any industrial asset, regardless of brand, age, or process. Reports are accessed anytime, anywhere via browser devices. This cloud-enabled Internet of Things (IoT) platform includes customizable dashboards and alerts, identifying manufacturing bottlenecks and inefficiencies, and streamlining manufacturing processes.
The Freedom Platform is available at three plan levels to right-size the program to individual shop and process needs.
The DST20 miniature strain sensor provides static and dynamic measurements of large forces across a range of 500µm/m to 1,000µm/m, even within limited spaces. Measuring 28mm x 12mm x 10mm, the screw-on sensors can withstand the rigors of industrial applications thanks to stainless steel housing and protection to IP65. They are suited to challenging industrial environments and mechanical engineering applications, as well as general process automation. The output signal is 1.0mV/V and connection is via an M5, 4 pin, male connector.
The OnRobot Screwdriver is a smart, complete-out-of-the-box device allowing manufacturers to automate a range of assembly processes quickly, easily, and flexibly.
Programming only requires entering the appropriate screw length and torque value into the user interface integrated into the robot’s teach pendant. With precise torque control and embedded axis, the screwdriver automatically calculates the necessary speed and force. It can detect incorrect screw length, improving overall quality and reducing scrap. With the Z-axis, screws are retracted inside the tool and driven automatically once the robot arm moves into position, which reduces robot arm movement and additional programming. Screws up to 35mm long are retracted completely inside the screwdriver when moving until the screwdriving process is safely initiated, enhancing its collaborative capabilities.
Advances in wire-based additive manufacturing (AM) technology have created new opportunities for prototyping, legacy part production, and aerospace tooling.
Manufacturers are under constant pressure to deliver prototype, production, and replacement parts at an ever-quickening pace, all while maintaining quality. Wire-based metal additive manufacturing (AM) technology can help manufacturers meet this challenge while:
Reducing lead times from months to weeks
Increasing design freedom, part consolidation
Speeding prototype testing
Light-weighting parts, lowering waste
Cleveland, Ohio-based Lincoln Electric, known for its arc-welding and cutting products and automated systems is at the forefront of AM, leveraging its in-house technology, materials, automation, and software to produce large, complex metal parts.
With a background in defense aerospace, Michael (Mike) S. Wangelin, business development and sales manager for Lincoln Electric Additive Solutions, who also represents Lincoln Electric subsidiary Baker Industries, Macomb, Michigan, spoke about innovations recently with Aerospace Manufacturing & Design (AM&D).
AM&D: What are the advances in wire-based AM?
Mike Wangelin (MW): Wire-based AM is basically taking an advanced gas metal arc welding (GMAW) power source, an industrial robot, and software that combines the robot’s motion with a multi-axis positioner to lay down successive weld beads to create a free-form 3D shape. It differs from metal powder-based AM in that the technology allows a larger build and is not limited to a build chamber. The only limitation is the movement of the robot or the cell used for the build. We’re currently working with a 4ft x 6ft x 6ft build volume and can expand that as needed. No special environment is needed, it’s just enclosed for fume collection with a localized shielding gas.
AM&D: What common industrial manufacturing challenges can AM solve?
MW: Prototyping in polymers or plastics can take a concept to a physical object in a short time, but it’s not representative of the actual part in strength or weight, so it’s limited to demonstration purposes, not functional testing. With our process, the strength would closely match or be the same as production. By initially prototyping with metal you can get to the point of what’s in production, whereas with polymers you’re limited to a conceptual object. Metal is a better match, closer to the end product.
AM&D: What replacement parts can you print on demand?
MW: Parts years out of production, often defined by paper 2D drawings, are difficult to reproduce in the current manufacturing environment. You can scan a part, capturing it digitally as an as-built object and recreate it quickly with 3D printing. Wire AM has greater surface variation than machined or cast surfaces – it’s near-net shape, so excess material may need to be removed from critical areas, but not necessarily entirely, saving time.
AM&D: What’s different about Lincoln Electric’s in-house technology?
MW: There are many 3D printing service providers in polymers and metal, many using off-the-shelf equipment and materials, so they’re limited to creating objects with what’s commercially available. What’s different about Lincoln Electric is that we’re in control of the entire process from start to finish, so we manufacture the power sources, welding equipment, and our own wire feedstock. Lincoln Electric has decades of experience in advanced automation and also owns and develops the software that takes the 3D model, creates the building routine, and controls the robot and positioner. Every piece, from startup design to completion of the product, is within Lincoln Electric’s control. Having the power of the large Lincoln corporation, we’re able to invest in each advanced technology segment along the way, driving the whole process.
Completed, machined Invar tool.
AM&D: What software has been developed?
MW: One key piece of establishing the 3D-printing solutions group within Lincoln Electric was having the software that sliced the 3D model to prepare it for 3D printing, generate the deposition tool path, and control the system. So, the company has taken software initially developed for complex 5-axis NC machining and adapted it to AM, a product called SculptPrintTM. Having the software owned by Lincoln Electric offers us the advantage to constantly make changes to the software as we learn about the process and gain efficiencies with it, so there’s no delay between identifying issues and making changes, where with third-party software, you’re running behind in making those advancements.
AM&D: What materials are you using?
MW: We’re currently printing steel, high-strength low-alloy steel, stainless steel, Inconel, bronze, and recently with Invar, a nickel-based alloy that has become the material of choice for aerospace composite cure-tools because its coefficient of thermal expansion matches the parts being produced. In addition, Invar has durability and wear benefits.
AM&D: What are the largest parts you can produce?
MW: Basically, a 5ft cube, but it’s part- dependent. If narrower, we can print up to 9ft – limited only by the robot’s reach. We could use a larger robot or pedestal to raise the robot if the need arises to go beyond our current build volume. A couple of projects we’re working on are 14ft long. We’re printing 4ft to 5ft segments vertically and joining the segments, welded together post-printing. Printing shorter segments also shortens the cycle time.
AM&D: What are the benefits of producing tooling with metal AM?
MW: As parts become more complex, lead times and costs start to come down with AM. Tooling is the last item needed before a production run, so there’s always schedule pressure to produce the tooling as quickly as possible, and we see this as our advantage, as we can cut cycle and delivery times, especially for complex tools.
AM&D: What are some examples of complex tools?
MW: Anything with high curvature such as inlet ducts, exterior skins with intricate contour shapes, multiple angles, or bends. Traditionally, you can form tools from plate stock with bumping and forming blacksmithing skills or machine it from a billet. With our wire additive, we can rotate the part, and the robot motion lets you build a complex part without a support structure. It’s well-choreographed to control robot motion and torch angle while rotating and spinning the positioner holding the part. Multiple pieces of equipment are rotating, all programmed with SculptPrintTM software.
Close-up of the weld stack in an aerospace composite tool.
AM&D: How is Lincoln Electric offering AM services?
MW: Lincoln Electric is selling the metal AM 3D-printing service as a print bureau, using a dedicated 75,000ft2 facility in Cleveland, which currently has 18 production cells. We’re working with Baker Industries, which uses its 35 3- and 5-axis CNC centers for machining, prototyping, or tooling, or we provide a print for customers to machine from near-net.
AM&D: How does the service work?
MW: A customer comes with the solid model and prints of a finished part or a tool to produce, giving us the parameters. We can design to requirements or use a completed design or a variation between the two. Or bring us an existing design of a product you’re trying to produce. We’ll build to print or we can redesign it for AM, offering alternatives to reduce time or cost. Or bring us an existing part, where tooling or drawings no longer exist.
Engineers and managers use measurement data collected by aerospace machinists and inspectors on shop floors and quality labs across the globe to satisfy customer requests, comply with Federal Aviation Administration (FAA) requirements or other government mandates, and monitor product quality and manufacturing performance.
However, manually collecting and retaining dimensional data is inefficient, can lead to costly errors, and carries expenses associated with storing and maintaining paper records for product life as required by the aerospace industry. Therefore, aerospace manufacturers are steadily reducing paper records in favor of quality data management software that can capture and store information digitally.
Demonstration of closed-loop manufacturing cycle using QIF standards.
Graphic, photo coutesy of Mitutoyo America Corp.
Digital thread
Aerospace relies heavily on its extended supply chain to produce quality products, but the massive volume of parts, part numbers, and suppliers involved in building aircraft makes it difficult to track products. Aerospace manufacturers highly support improving the supply chain so they can improve part quality, profit margins, and the overall safety of air travel.
This can be achieved by adopting the digital thread – digital information that can be tracked through every part’s life cycle. Quality data management software plays a significant role in an enterprise’s ability to support the digital thread. Software contains essential information such as the part’s tolerances and as-measured values. Process capability statistics calculated from these measurements can generate performance charts for the manufacturing process. When necessary information isn’t accessible to those who need it, or to other software that can use the data, the extended enterprise is not being as efficient as it could be.
Manufacturers who implement the digital thread must choose interoperable software that uses a communication standard such as quality information framework (QIF).
Aligning QIF standard
Released and accepted as an ANSI standard in 2013, QIF has been submitted by the Digital Metrology Standards Consortium (DMSC) to ISO/TC 184/SC 4 Industrial Data as ISO/DIS 23952. Once accepted, the standard should become more widely adopted.
Adopting the QIF standard should give aerospace manufacturers clearer insights into all parts and products received. QIF stores product information in documents written in extensible markup language (XML). Since XML is commonly used, QIF documents can be easily transferred across tiers of suppliers to the aerospace manufacturer through their enterprise resource planning (ERP) software, all of it potentially different.
However, when software application developers create proprietary communication protocols, or if private organizations create their own standards, the entire industry takes a step back. Information is no longer shared effortlessly. Because organizations can’t agree on which protocol to adopt, the enterprise eventually resorts to spreadsheets and PDFs to share information. If a proprietary format is agreed upon, it becomes costly to adopt since it was developed by private organizations that have their own interests in mind.
QIF, however, is free. The XML format is easily adoptable and can allow companies to choose applications that best suit their needs rather than applications that only work with a particular machine or software.
Measurement data is captured by MeasurLink, Mitutoyo’s quality data management software. Critical characteristics from an aerospace part are checked for conformance by Mitutoyo’s CNC roundness tester. MeasurLink provides real-time feedback for the inspector, while the data is also available for post-analysis and reporting.
Tracking serialized parts
For serialized aerospace parts, conventional characteristic naming systems, including balloon IDs, are being supplemented with universally unique identifiers (UUIDs), a standardized format ISO/IEC 9834-8:2005. Conventional characteristic naming systems are being supplemented because they cannot provide unique identifiers across the enterprise.
QIF results files are serialized and ideal for long-term archiving and retrieval (LOTAR) (http://lotar.prostep-ivip.org), eliminating problems related to managing, tracking, and locating measurement data for specific parts or characteristics.
For example, a database search for “Diameter_28,” would return thousands of results for that characteristic from numerous parts and assemblies. However, a characteristic search in one or many QIF documents finds a specific UUID that returns immediate and exact results for an ID that will not be duplicated.
Close the loop
In a machine cell, a QIF document containing measurement results and statistics can feed information back to a machining center for controllers to make tool offsets, ensuring high-quality manufacturing.
Machine tool controllers are becoming more intelligent every day, and many can manage tool wear, estimate cycle time, and report machine condition. However, all these functions require information. To adaptively compensate for tool wear, the information needed by the machine tool controller must be actionable, which, in this case, is measurement results and statistics. For example, measurement data coming from a coordinate measuring machine (CMM) measuring newly machined parts can be calculated into useful process capability statistics by the quality data management software. The machine tool controller can then read the information from a QIF results and statistics document to make necessary corrections on the next part automatically. Closed-loop manufacturing keeps costs low, parts in tolerance, and process capability high. It also frees up operators to do other tasks and only requires them to get involved with tool offsets during critical situations.
An operator uses a Mitutoyo caliper to capture data inside MeasurLink. The data is transmitted electronically and stored in a centralized database for easy retrieval and long-term archival.
Manufacturing future
The future of manufacturing lies in the smart factory – more data, more sensors gathering the data, and a more interconnected manufacturing space.
A smart factory requires aerospace machine and software suppliers to be able to communicate and share part and measurement data with one another by leveraging QIF and using the digital thread. Part quality can be confirmed, and manufacturers can be more responsive to real-time issues impacting delivery.
Manufacturing plant interconnectivity between different software applications and machines, and information sharing with partners and suppliers through the entire supply chain, will be integral to profitable aerospace manufacturing.
About the author: Hany Abdel-Motaleb is the MeasurLink & data management specialist at Mitutoyo America. He can be reached via email at hany.abdel@mitutoyo.com or at 888.648.8869.
Inspection techniques to improve parts yield
Features - inspection
Precise shop-floor measurements can shorten turnaround time while maintaining quality.
3D measurement of a scratch with two profile traces showing variability of results by location.
All photos courtesy of Onto Innovation
Speedy quantification of part defects directly leads to faster turnaround time (TAT) via reduced inspection times. Accurate metrology removes any doubt about the severity of defects, reducing scrap and increasing yield to further improve TAT.
Widely used inspection techniques in maintenance, repair, and overhaul (MRO) shops can provide quick TAT but often can’t accurately evaluate defects. Alternatively, techniques that provide needed accuracy can come at the cost of a quick TAT. To provide fast and accurate defect detection, 4D Technology developed the 4D InSpec Surface Gauge, putting metrology and 3D measurement on the shop floor.
3D analysis of corrosion pits, automatically finding pits that are in different categories.
Speed vs. accuracy
Visual tests and fingernail inspection rapidly find defects. Inspectors use their fingernails to make an educated guess as to how large a nick, scratch, or bump is. It provides no quantifiable data and is subjective, though some inspectors are good at classifying larger defects into a range of depths. When unsure whether a defect is acceptable, inspectors tend to err on the side of caution and reject it. That gray area often leads to rejecting parts that meet specifications. Visual inspection only correctly identifies about 85% of bad parts and improperly rejects 35% of good parts, studies show.1 The result is the loss of millions of dollars in good parts by MRO facilities every month. Visual and tactile inspection may provide all-important quick TAT, but at a cost in yield. Rather than a fingernail, a scribe gage better quantifies parts, but they often can’t penetrate to the bottom of parts, and finding a proper reference area on complex geometries adds further uncertainty.
Another defect measurement technique is using replication, combined with an optical comparator or stylus profiler. This method uses costly replication materials, can take around 30 minutes to complete, and provides only 2D traces across a single defect. Defects aren’t mapped along their entire extent – the deepest part of a pit may not have been crossed by the measured cross-section, leaving the deepest point unknown. Additionally, it’s not always visually obvious which pit is deepest, as discolorations and shadowing can cause uncertainty. Through any of these limitations, inspectors reject parts rather than passing a potentially bad component.
Nanometer-scale resolution inspection that removes the gray area but typically requires measurements to leave the shop floor to be inspected with lab-based 3D optical profilers or contact-based stylus profilers. Shipping processes and demand for the instruments can push TAT to weeks. The instruments are significantly more expensive than other processes (up to $200,000) and require a designated, trained operator. And, systems only measure small parts and samples, meaning larger parts require review of replicated defects. These systems provide the high resolution necessary to accurately measure defects and increase yield at the cost of TAT. Often, operators will reject or rework parts for unquantified defects rather than slow the process to accommodate high-resolution techniques.
Measurement of edge break radius, showing the radius in 3D (center) and the two adjoining surfaces (right).
Shop floor metrology
Working with the three largest engine manufacturers and various MRO organizations, 4D Technology set out to put a high-resolution instrument on the shop floor. The 4D InSpec and 4D InSpec XL are vibration-immune, 3D surface gages designed for portable, rapid, precise measurements at existing inspection stations. Polarized structured light technology allows the gages to be handheld while maintaining a height resolution of 0.0001" (2.5µm).2 Inspectors can perform accurate, in situ defect quantification without sending parts to a lab.
With non-contact and non-destructive measurements of surfaces ranging from rubber to polished metal, defect analysis with the 4D InSpec is like taking a picture. The instrument communicates to a desktop, laptop, or tablet with an Ethernet cable. Data collection and analysis occur in a fraction of a second, displayed through analytical software for the inspector. Aviation customers can use a backpack power supply and handheld tablet for maximum portability for applications, such as on-wing measurements.
Taking measurement systems to the part reduces TAT by providing instant data and reduced labor. Fold mirror attachments allow 4D InSpec to take measurements that aren’t within line-of-sight. At one aviation manufacturer, being able to access tight spaces saves a week of labor – per measurement – by eliminating the need to disassemble everything.
A rivet as viewed through the instrument camera (left), and a 3D plot of the rivet with traces drawn in X and Y (right) help evaluate peak height and planarity of the rivet, as well as evaluating defects like voids.
Instant 3D measurement
2D techniques, such as styli and optical comparators for defect measurement, are common on shop floors, but there are drawbacks to lacking an area-based measurement. There is no way to guarantee a 2D trace measures the most extreme part of a defect, and each defect must be measured sequentially. For parts with many defects, this can become time-consuming.
3D measurement maps each defect in the field of view – guaranteeing that the deepest part of a long scratch was measured. Measuring every defect in the field of view simultaneously allows quantifying dozens of corrosion pits, so the deepest point automatically displays.
InSpec’s design allows macro area-coverage and access to recessed features, while maintaining high vertical and lateral resolution. The software’s Feature Analysis displays all data for every feature in the measurement so inspectors don’t have to individually evaluate each defect individually. This is especially useful for inspecting corrosion pitting or dot peening. Precisely measuring defects means inspectors can stop padding depths due to uncertainty, reducing unnecessary rework and rejection of otherwise good components. Additionally, results can be printed, exported to a file, or uploaded into a facility’s quality control system, providing a comprehensive digital record of the measurement. Records can be reviewed and even re-analyzed later should there be any question about the results.
4D InSpec on the left, and the 4D InSpec XL with a larger field of view.
Qualifying geometries
3D measurement is also a powerful tool for assessing critical small geometries such as edge break, radii, and chamfers. If a 2D trace is not perpendicular to such a feature, the radius of curvature or chamfer length calculated will be artificially larger, due to improper trace orientation. Edge break and feature radius are important callouts for many aviation components. Relying on an operator to get the exact 2D trace correct is unrealistic. 3D data allows software to mathematically find the true radius of curvature or chamfer angles and dimensions, independent of human judgment. Since the feature is sampled across many hundreds of lines, the results are more comprehensive and reassure operators of their accuracy.
Rivet analysis
A 3D measurement of a rivet enables software to analyze the planarity of the rivet and its depth or height relative to the surrounding surface. Users can set pass/fail thresholds in the software based on their specifications and receive immediate feedback for each measurement.
Conclusion
As the MRO industry works to improve TAT while maintaining quality, the need for precise shop-floor measurement is increasingly important. Accurate, simple 3D metrology allows inspectors to qualify parts right up to the specification line. This reduces unnecessary rejection and rework without the risk of passing bad components. A handheld shop floor gage allows automatic determination of the deepest feature within the measurement area, across multiple pits or scratches if they are present. Such measurements provide edge break, chamfer, and radius analysis, allowing one system to accomplish multiple inspection tasks. Finally, a digital record of measurement results is critical, should it be necessary to review history and the exact results.
NOTES: 1. See, J.E.: Visual inspection reliability for precision manufactured parts. Human Factors 57(8), 1427–1442 (2015)
2. Joanna Schmit, Erik Novak, and Shawn McDermed “Inspection of mechanical surfaces with polarized structured light,” Proceedings SPIE 10834, Speckle 2018: VII International Conference on Speckle Metrology, 108342F (7 September 2018); https://doi.org/10.1117/12.2322178
