Dimensional Measurement Blog

 

In manufacturing industries where the difference in a decimal point may determine whether a 21^st century elite battleship sinks or floats, quality is as integral as the bolts that bind that vessel together. Finding a dimensional inspection lab that can not only proficiently provide a variety of services, but also do so reliably and consistently can prove to be a daunting task if you are not equipped with the right criteria. Although each manufacturer has different dimensional inspection priorities, there are a few key factors to consider in finding out if a dimensional inspection provider will help you operate more efficiently and possibly save you both time and cost in the process.

Key qualities to consider when selecting a dimensional inspection service provider are:

• Industry Expertise - Almost any engineer can perform basic dimensional inspection with a little training. In fact, there are many reasons engineers benefit from learning more about metrology. However, dimensional inspection in the context of the manufacturing world is an entirely different story. You need a partner that understands industry-specific requirements, manufacturing methods, and can interpret engineering drawings properly. If they are already familiar with the factors involved in measuring your application, the expertise of your dimensional service provider can help in maintaining a tight production schedule. An experienced provider will be able to not only provide you with a detailed measurement report, but also advice on how the results may directly affect your application.

• Modern Equipment - Although the field of dimensional measurement has existed since even before the first standardized measuring tools were created, the technology is constantly evolving. A facility that doesn't stay on the cutting edge of 3D scanning technology and all the other measurement technologies and methods may not be able to provide the most efficient and accurate services. Look for a lab that regularly updates its equipment inventory so that you can get the best service now and in the future.

• Attention to Detail - Even the smallest cut corner can have a major impact on a manufacturing process, which is why working with a provider that is as committed to the little details as you are is so important. As the world of manufacturing in progressing more into the nano realm than ever before, it is important to consider a provider who can offer both accuracy and insight into the needs for dimensional inspection across the size scale for manufacturing.

• Broad Capabilities - As the world of manufacturing is progressing more into the nano realm than ever before, it is important to consider a provider who can offer both accuracy and insight into the needs for dimensional inspection across the entire size scale for manufacturing.

• ISO 17025 Accreditation - An ISO 17025-accredited lab must meet certain quality standards so that you can be confident that your project will get the attention it deserves. ISO 17025 accreditation meets and exceeds the requirements of ISO 9001. Although many dimensional measurement facilities achieve ISO 9001 registration, not as many make the extra effort for ISO 17025 accreditation. The advantages of using an ISO 17025 accredited lab are numerous. For example, each measurement machine in a scope of accreditation must be subject to rigorous measurement uncertainty studies and round-robin testing in addition to accredited calibration.

• Technological Aptitude - Metrology technology and equipment are constantly evolving, which means there are always new ways to do the job better, faster, or in a more affordable manner. Look for a partner that has competence in all the modern methods of dimensional inspection using the latest technology so you can reap the benefits.

• Forward Thinking - The manufacturing process requires many steps, and to get it right the first time, you must have foresight and think strategically. Look for a provider that is invested in the whole process, not just the measurement tasks you require. An experienced dimensional metrology provider should be able to consider all factors when it comes to measuring your application, and provide you with a coherent plan that includes aspects such as your budget, your team's experience, and overall quality goals.

• Qualified Employees - Dimensional measurement requires both training and experience. Make sure your provider is staffed with technicians who have the level of expertise required for your application.

• Prompt Service - Some dimensional measurement services can't happen overnight, but you should be able to communicate with your provider as often as necessary. Look for a lab that responds quickly to your inquiries and has the flexibility and capacity to provide rush services if you need them.

Poor testing procedures and inadequate equipment can cost you a lot of time and money, both in the short-term and in the long-term. In order to meet minimum quality standards you need the right equipment and a trained staff that knows how to use it.

Q-PLUS Labs has been a leading dimensional measurement laboratory since 1987; providing one place for precision measurement solutions. As a lab registered to ISO 9001 and accredited to ISO 17025, you can be certain that you will get the right dimensional measurements every time, on time. Contact us today for an assessment.

 

 

With their repeatable accuracy and programmability, coordinate measuring machines (CMMs) have universally been known as the ultimate dimensional measurement and inspection equipment by using contact probing to deliver single point by point sparse measurement data. However, 3D scanning is widely accepted as an effective, accurate, and fast way to collect and analyze measurement data. The integration of robotic technology with structured light 3D scanning systems has made tremendous progress that, under optimum circumstances with high-end equipment, now approaches the accuracies of CMMs, but captures millions of measurement points in seconds without any contact to the part. With the growing demands of accurate measurements involved in manufacturing, it is important to understand what types of measurement devices are available for your application as well as the strengths and weaknesses of each.

What is a CMM?

Coordinate measuring machines (CMMs) are mechanical systems that use a contact measuring probe and transducer technology to convert physical measurements of a surface into electrical signals that can be analyzed by specialized metrology software. CMMs range from basic XYZ read-outs utilizing hard-probes to fully automated systems with articulating continuous contact probing that can perform CAD model-based inspections. The measurement envelope of CMMs ranges from desktop systems to those large enough to measure an entire car and beyond. Since volumetric accuracy is usually stated as an equation in which the error increases as a function of size, larger CMMs generally tend to have less accuracy then smaller systems. However, just because a CMM is large does not mean it cannot also be accurate. CMMs that are large and accurate exist but certainly cost much more. While both manual (free floating) and DCC (Direct Computer Control) CMMs can be programmed, DCC-CMMs are robotically driven by motors instead of the operator. This makes for huge time savings in inspecting many of a given part configuration, over and over again. However, with power, comes responsibility. Automated measurement systems such as DCC-CMMs have the possibility of a programming error which can lead to it being misused, causing damage to the CMM or the part being measured, however newer software reduces the chances of such accidents.

The sensors for CMMs are not limited to touch probes. Advanced systems can also include continuous contact scanning probes, indexable vision sensors, laser scanning heads, and even surface finish probes. CMMs measure points and DCC-CMMs can control the direction in which these points are measured. Everything else is in the software, which makes the features of the software integral to the machine's output. It's important that the software offer the right combination of power and ease of use. All CMM software provides for taking measurements of points and basic geometry such as planes, circles, and lines, as well as cylinders, spheres, cones, and more. Operations are then performed on the geometrical elements which are then generated into dimensional readings, compared against design tolerances, and distilled into reports. Newer CMM software allows for model based inspection where the CMM measurements and program are written using a 3D CAD model of the part of interest. Special software modules exist for complex parts containing airfoils, gears, or free-form non-prismatic geometry. However, contact sensors generally do not work well for dimensional inspection applications where the object is soft, elastic, or extremely small.

What Is a Structured Light 3D Scanner?

One of the most common types of non-contact 3D scanning is structured light scanning. Sometimes also called white light or blue light scanning, this method of 3D scanning includes a projection light source which could be either white or blue light, and involves projected light and typically 1 or 2 cameras to measure the three-dimensional surfaces of an object via triangulation. To obtain scan data via triangulation, a pattern of light is projected usually in a series of parallel lines which become distorted on the surface of the object when viewed from a perspective different from the projector. Each camera utilized captures this distortion from varying, sometimes multiple angles, and triangulates the distance of numerous points on the part being scanned. Finally, these three-dimensional coordinates are used to digitally reconstruct the details of the object. As part of the post-processing, the digital “mesh” of facets is created from these scans at multiple orientations via software which cleans the scans up, merges the multiple scans, and stitches them all together. This meshed representation can then be used to perform dimensional inspection operations or reverse engineering.

This method of 3D scanning can be used on objects and quickly captures a high volume of data without impacting the surface of the object. Because structured light scanners operate with immense speed relative to measuring devices like CMMs that measure at each area that the probe comes into contact with, producing a sparse amount of points, structured light scanning offers advantages, particularly with data density, that are simply not feasible on a CMM. Like CMMs, structured light scanners comes in various sizes and can be used on everything from the micro scale such as orthodontics all the way to large volume objects such as airplanes (when used in conjunction with retro-reflective targets and photogrammetry). Other applications for this technology would be when contact probes like CMMs are not appropriate. For example, if the object is elastic, delicate, or otherwise difficult to handle, structured light scanning can be used without any physical contact with the object being measured. The use of structured light scanning on a specific application depends on factors including surface characteristics such as reflectivity, transparency, and roughness. In some cases, structured light scanning is not an appropriate method because diffraction and reflection can affect the measurements. This can usually (but not always), be overcome either by special system settings or by the application of a fine and easily removable chalk spray.

Consider All Factors

There are several factors to consider when choosing measurement equipment. It is important to understand how each of these factors will affect your application's measurements.

• Accuracy of measurement results
• Portability of the system
• Size of the parts being measured
• Features that will be measured
• Degree of automation required during measurement
• Speed of the measurement process
• Cost of the system
• Cost of training operators

CMMs still and will continue to play a vital role in today's dimensional metrology applications, however structured light scanning can offer many advantages in scenarios where:

• the given application has a large amount of complex geometry
• a high percentage of the parts need to be measured
• the parts can’t accommodate contact measurement
• the measurement process needs to be very fast

Since 1987, Q-PLUS Labs has been a leading dimensional measurement laboratory specializing in assisting companies with finding the right measurement solutions to meet their needs. In addition to offering a vast product line, Q-PLUS Labs provides both CMM and 3D scanning services and products, in addition to a full range of other dimensional measurement and inspection services. Contact us for answers to your dimensional measurement and inspection questions or to request a quote.

 

 

For some products, the manufacturing process does not end once those products are packaged and shipped out. In the case of automobile manufacturers, many of the final vehicle's components come from various suppliers and are assembled to build the cars we enjoy driving. Because the quality of these components work together to comprise the overall quality of each vehicle, and thereby the quality of the car's brand, it is imperative that each of the vehicle's components from those various suppliers must be carefully examined for non-conformance. What happens when a supplier's shipment of non-conforming parts is already on its way to the other side of world? What measures can be taken to maintain the brand's integrity and keep consumers safe, while adhering to a tight schedule?

Response Time: Once the supplier knows there are non-conforming parts that are already on their way to a warehouse or distribution center, timing is critical. If there is a tight schedule to maintain, then either sending the shipment back to its point of origin to be sorted and reshipped, or having a team sent out from the supplier's location to the shipment's destination to inspect the defective shipment are options, but can be costly both in time and money. Alternatively, enlisting an on-site team who can perform all the necessary parts sorting and inspection services, and who are already located at the shipment's destination can help the supplier stay on schedule and deliver value. Once the shipment arrives, the on-site inspection team will already be in place to work diligently to contain the defective parts, sort the parts that meet specifications, gather the relevant data that the supplier wants to know about their shipment, or assist with any necessary part rework, repair, or assembly.

Reliable Data: If the supplier does not already know, they will quickly need to know the extent of the non-conformance of the parts in the shipment in order to determine how many conforming parts need to be produced or shipped to replace the defective parts in the shipment. Is it the entire shipment or is the defect limited to a certain quantity of parts? It is important to know how much of the shipment is defective, how these parts are defective, as well as the measurements of the defective parts if the defect is related to dimensional measurement. Sometimes these measurements can be quickly collected at the shipment's destination, or in the case of non-conforming parts with tight tolerances which demand accurate measurements, the defective parts may have to be sent to an environmentally controlled dimensional metrology lab. Obtaining the measurement data, whether at the shipment's destination or in a controlled lab, will save the supplier the time and cost it would take to send the entire shipment back to its point of origin to be sorted and inspected. This data can be used to produce the correct parts and ship them out while the non-conforming parts are on their way back to the supplier or are dispositioned.

Rework or Repair: Once the defective parts have been sorted from the parts that meet conformance, and the supplier has reliable measurement data which they can use to know how much the defective parts deviate from the conforming ones, sometimes the supplier can use this data to rework or repair the bad parts currently at the shipment's destination. In certain scenarios that do not require a part to be held to an extremely tight tolerance, rework or repair can be as simple as smoothing out a dent or deburring a rough edge.

Parts Sorting & Inspection Services as a Value-Added Solution

Q-PLUS Labs is a fully equipped dimensional metrology lab that has over 30 years experience in dimensional and on-site inspection. Our personnel are veterans at helping our customers maintain their product's integrity and are fully capable of providing an on-site parts sorting and inspection team able to respond and arrive at your location typically within 24 hours. As a registered ISO 9001 and ISO 17025 accredited laboratory deeply knowledgeable in serving industries including Solar, Energy, Automotive, Aerospace, Medical, and Defense, Q-PLUS Labs can help you keep your tight schedule while maintaining and delivering the quality associated with your brand.

Contact us for information on how we can add value to your manufacturing and production process.