Dimensional Measurement Blog

In order to obtain an engineering degree, you must learn certain concepts and skills in school. However, developing an engineering career means your education continues on the job. One field not typically taught extensively in engineering school is metrology, but for any engineer entering the field of manufacturing, understanding metrology is essential. 

In the simplest terms, metrology is the science of measurement. In practical terms, when it comes to manufacturing, engineers have a vested interest in knowing the fundamentals of geometric dimensioning and tolerancing, commonly referred to as GD&T. Engineering drawings and 3D CAD models use GD&T to communicate engineering dimensions and tolerances to manufacturing and quality staff. If the engineer doesn't know how to effectively communicate in the language of GD&T, the finished product will likely not meet the desired outcome.

Why Understanding Metrology Is Important

The purpose of engineering design is to convey information in a way that makes it as easy as possible for the manufacturing team to create the desired parts and assemblies. A good engineering drawing will consider:

• The design intent
• The people and processes involved in manufacturing
• The inspection and verification process

The consequences of not understanding the fundamentals of GD&T can be dire:

• Disruption of manufacturing schedules
• Damaged reputations because of the inability to fulfill requirements
• Inability to meet budgets

Because metrology is so important in the manufacturing industry, there are several benefits for young engineers to learn it sooner rather than later:

1. Quality - Good engineering drawings result in parts that match the design intent.
   
   
2. Budget - Getting a drawing right the first time saves money.
   
   
3. Time - When dimensions and tolerances are stated clearly and thoroughly, manufacturers do not need to take the time to ask questions or get clarification.
   
   
4. Customer satisfaction - Producing the correct results in a timely manner keeps customers happy.

So how does a engineer learn more about GD&T if it's not commonly part of the standard curriculum? The American Society of Mechanical Engineers (ASME) offers the Y14.5 - 2009 Dimensioning and Tolerancing specification. This set of guidelines describes the language of GD&T and establishes uniform practices for communicating the requirements on engineering drawings. Additional resources include training programs and traveling seminars.

Q-PLUS Labs offers both training and consulting services to help ensure that your manufacturing process goes as smoothly as possible. Our training programs are designed for small groups across multiple disciplines so that engineers, manufacturing staff, and other key players can learn how to most effectively communicate in the language of GD&T. Contact us today to learn more about how we can help you.

Are you an engineer in the field of manufacturing? Tell us in the comments section how you learned about GD&T.

 

3D scanning can be used for a broad range of applications. For example, you might want to create a replica of an artifact or inspect a sand casting to a 3D CAD model. However, not all dimensional measurement applications warrant the use of 3D scanning. In some cases, a different or simpler approach might be appropriate.

So how do you know when not to use 3D scanning? If any of these three applications are similar to yours, you might want to re-evaluate your approach:

1. You only need to measure one dimension - The whole point of using 3D scanners is to measure objects in three dimensions. If you only need to know the length or width of an object, a simpler (and less expensive) measurement system or gage may suffice.
2. You need an extraordinarily high level of precision - certain high-end 3D scanners have the ability to produce very precise results, but some applications call for an immensely high degree of accuracy and precision. If you are measuring the profile of a ground cam or a high-speed gear, a non-contact 3D scanner will not likely be a viable solution.
3. Your object has interior surfaces that cannot be seen - If you can't see a given surface, an optical 3D scanner can't see it either. In these cases, a contact probe can often reach the geometry of interest such as a bore hole or other interior surfaces. In other cases, however, sectioning or slicing of the object may be required. CT scanning is also a possible solution however this method has several limitations of its own.

Fortunately, 3D scanners are just one of many tools in the dimensional measurement toolbox. Other types of measuring devices you can use include:

• Direct computer control coordinate measuring machine (DCC-CMM)
• Optical video probes and comparators
• Contour and form testers
• Reverse Rapid Prototyping system (CGI)

This short list represents just a few of the options that might be useful for your dimensional measurement applications. The best way to determine what type of equipment best matches your needs is to work with a qualified dimensional measurement service provider that has the experience and expertise to help you decide.

Q-PLUS Labs provides 3D scanning and a range of other dimensional measurement and inspection services, so no matter what measurement problem you are trying to solve, we can help. Contact us today to schedule a consultation.

What projects are you considering for 3D scanning? Might another measurement method provide the results you need?

3D scanning can be used for a broad range of applications, some of which you might not expect. It can be employed in any situation where the size, shape, and surface characteristics of an object are important. Advances in the technology have further broadened the scope of its utility. It is possible to measure geometry with greater accuracy as well as to capture small details that were previously not possible to measure.

The purpose of 3D scanning is to capture surface geometry, but the reasons you might want to do this can vary significantly. Some of the most common applications include:

1. Reverse engineering and protoyping - There are many reasons that one might want to replicate an object through reverse engineering, and 3D scanning is one of the most effective ways to create an accurate representation of the original object. The level of accuracy required can also vary depending on the application, so it is important to understand the objectives for reverse engineering.
2. Manufacturing quality control - In many cases, parts coming off a manufacturing line must meet specifications within a certain tolerance range. 3D scanning can be used to accept or reject products for quality control, and to ensure that mass-produced parts are able to fit together properly and consistently.
3. Industrial metrology - A highly detailed 3D representation of a machine part can be used to evaluate wear patterns, confirm the final build, and analyze other complex surfaces. It can also be used to replace old parts that do not have an existing CAD model.
4. Medical applications - Teeth, bones, and even skin surfaces can be modeled using 3D scanner equipment. This information can be used to create prosthetics, orthotics, and other medical devices.
5. Movie production - The entertainment industry uses 3D scans for visual effects and other 3D graphics. This technology is also commonly used for video games and animation. View our 3D scanning gallery to see how 3D renderings of people and other objects can be generated.
6. Artifact documentation - Archaeologists and other scientists can use 3D imaging to create replicas of unique artifacts and other materials of interest without damaging them. The scans can also be used for modeling, documentation, and restoration.

The type of 3D scanning equipment you select depends on the application and a number of other factors. Choosing the right equipment early in the process can help you save money and produce the best possible results. Q-PLUS Labs is here to help you select the right equipment, or you can outsource some or all of your 3D scanning needs directly to us. Contact us today to learn more or to schedule a consultation.

What 3D scanning applications have you used in your business?

 

Reverse engineering allows you to obtain the exact dimensions of an object so you can replicate it. Specialized laboratories have various types of equipment to measure almost any type of object, no matter how large or small, or detailed or precise. The measurements are then delivered in a format that will allow you to produce a copy. You might need to reverse engineer a custom part, an object that does not have original design plans, or a unique antique.  

Reverse engineering services can be extremely specialized, and not every provider can meet every need for every customer. Ask your lab the following four questions to ensure that you will receive the quality results you require:

1. Do you understand the application?

Reverse engineering a tennis racquet frame for a 3D digital marketing video requires relatively little precision. However, if the reason for reverse engineering is to produce an exact replica of an engineered airplane part, an entirely different (and possibly more expensive) measurement process will be required. Make sure your provider understands your reasons for reverse engineering so they can select the best measurement method for the application and your budget.

In addition to accuracy, it’s very important to specify between design intent or as built reverse engineering.  Design intent reverse engineering corrects for errors in the object’s original manufacturing.  As built reverse engineering closely matches the original design including its imperfections.  For example, a statue is a good example of something that would use the as built method whereas a damaged piston will certainly require the design intent approach. Both have their place and the choice will be determined  by the given project.

2. Do you have the right equipment for my needs?

If you do need a high level of precision, make sure the reverse engineering lab has equipment that meets the required specifications. In the case of a threaded nut, the equipment will need to measure both interior and exterior surface dimensions; not all measuring devices can do this as accurately as others. The type of material also matters when selecting equipment. If the surface of your object is reflective or elastic, different types of sensors are required. Talk to your provider about the equipment they intend to use and their reasons for selecting it.

3. Can you produce a deliverable format that meets my needs?

Reverse engineering results can be delivered in a format as simple as a PDF (such as an engineering drawing), as detailed as a parametric 3D CAD model, or somewhere in between. Make sure your provider delivers a file that includes enough detail for your application and is compatible with the software you intend to use during the replication process.

4. Can you produce timely results?

Your deadlines might impact the choice of equipment and measurement methods. In general, higher precision measurements take more time. Make sure your provider understands all of your priorities, including the amount of time it takes to produce results.

Q-PLUS Labs provides reverse engineering services for a broad range of industries and applications. Our wide array of dimensional measurement and 3D scanning equipment allows us to tailor measurement processes to your needs, so you can get the type of results you need, when you need them. Contact us today to learn more.

How has reverse engineering helped you grow your business?

Reverse engineering can be used for a broad range of applications, from precisely duplicating an airplane part that is no longer manufactured to making a mold to replicate an antique statuette. The type of reverse engineering required will depend on the specific application and the necessary degree of precision. Knowing these factors in advance can help you determine the type of reverse engineering that makes the most sense so you can get useful results and make the appropriate budget decisions.

Exploring two extreme ends of the spectrum illustrates the difference between reverse engineering types and why it is important to understand them.

Case 1: Precision is important

Various factors are considered when determining the best method for reverse engineering. Take the example of an aircraft part or biomedical device. You have the original part, but no design specifications. In this case, the following factors are considered:

1. Original object - Because having a high degree of precision is important, several original parts are required to generate the most accurate duplicate part. These several parts will be measured and compared; the average measurements are typically used to replicate the part.
2. Tolerance - This represents the range of measurements that are acceptable. When working with a regulatory body such as the FAA or FDA, you generally must stay within a certain allowable deviation.
3. Accuracy - A high degree of accuracy is required to meet the desired function of the part.
4. Measurement approach - Many types of measurements using various contact and non-contact sensors will be taken with either a low-density ordered data or high-density data approach, possibly with millions of points to get the most accurate and detailed information possible.
5. Purpose - You may want to create new tooling or parts for a high-precision application, or duplicate a part for which you do not have existing specifications. The result might be parametric CAD models, 3D mesh files, or engineering drawings that can be used for manufacturing.

Case 2: Precision is less important

When replicating an object that is not subject to regulatory scrutiny, a less strict approach can be taken. The same factors apply, but they are handled differently:

1. Original object - Generally only a single original object is required.
2. Tolerance - The tolerance levels may not be important at all, making the measurement requirements significantly less onerous.
3. Accuracy - The original object may have a more free-form geometry that does not require the same degree of accuracy.
4. Measurement approach - Only 3D scanner measurement data may be required to generate a suitable duplicate and engineering drawings are generally not required.
5. Purpose - You may want to get a digital representation of a product for a marketing video or reproduce products for manufacturing. The result might be a 3D mesh or non-parametric CAD model that can be sent to a rapid prototyping machine and also allows you to compare reproductions to the original.

Of course, there are a broad range of examples that fall between these two ends of the spectrum. A good reverse engineering lab can help you determine which reverse engineering approach is right for your project.

If you need reverse engineering services, contact the experts at Q-PLUS Labs. We provide 3D scanning & digitizing, precision CMM measurement, 3D CAD modeling, and engineering drawing services to help you reverse engineer any type of part. Contact us today to learn more about our services.