Dimensional Measurement Blog

3D scanning can be an effective tool for first article inspection. It is relatively fast, produces accurate results, and can be more cost-effective than other solutions. However, 3D scanning does not work for every first article inspection application. For example, if the part includes internal features or surface finishes that are not compatible with optical inspection tools, a different approach might make more sense.

If you have determined that 3D scanning is the right method for your application, following a set of key best practices will help ensure that you achieve the highest quality results.

First Article Inspection Best Practices

1. Accuracy - Although accuracy varies depending on the application, a good guideline is for 3D scanning to be 4 to 10 times more accurate than the tolerances for the part. If you're not sure what to specify, work with your provider to determine the range that will produce the results you desire.
   
   
2. Object condition - Make sure that the part you are scanning is clean and free from any surface debris. This is especially important for non-contact 3D scanning because any particles left on the object will be included in the point cloud obtained during the scanning process.
   
   
3. Speed - First article inspection typically depends on speed. Most manufacturers want to get confirmation that a part meets specifications as soon as possible so they can start or continue production or take corrective action, if necessary. Working with a 3D scanning lab before you provide the part for inspection can improve the turnaround time for results. Your provider can do advance work such as pre-programming the point cloud inspection software (such as Rapidform XOV or Geomagic Verify) to make the scanning process more efficient.
   
   
4. Quality - When it comes to first article inspection, results are extremely important. A mistake can cost manufacturers time and money. Although speed is an important factor to consider, it should not come at the expense of quality.
   
   
5. Experience - 3D scanning is still a relatively new dimensional inspection technology, and not every lab has expertise with the equipment and software. Make sure you work with a certified provider that has a track record of success with 3D scanning.

Q-PLUS offers 3D scanning services for a broad range of industries and applications, including first article inspection. We'll work with you throughout the entire process to ensure that you get the fastest, best results. Request a quote today to learn more about our 3D scanning services.

What are the challenges you experience with performing first article inspections?

First article inspection is an important component of successful manufacturing. The first article in production must be inspected, or measured, to determine whether it meets the engineering specifications. If it does not, corrective steps must be taken. These steps take time and money, which is why first article inspection must be quick and accurate.

10 Common Mistakes with First Article Inspection

1. Not including the drawing title block requirements such as general edge breaks, concentricity requirements, and others.
   
   
2. Not reviewing the marking character-by-character to the marking requirements for syntax errors.
   
   
3. Not including specifications listed in the drawing notes that will have a dimensional or interpretive impact on the drawing features.
   
   
4. Not accounting for features that apply to multiple places on the part.
   
   
5. Failure to properly address drawing notes and flag notes -- ensuring that items with a specific location via a flag note are, in fact, in the correct position is important.
   
   
6. Overlooking cavity number, dash number, or serial number part identification requirements.
   
   
7. Failure to correctly place raised markings, especially relative to tooling points or surfaces.
   
   
8. Cleaning up or benching surfaces with tooling points or datums which alter the native surfaces produced by the tooling and can have a pronounced effect on the inspection results.
   
   
9. Failure to include surface finish and coating requirements, especially when they apply only to specific locations or zones.
   
   
10. Failure to properly measure small arc segments with relatively tight tolerances, especially those with large radii.

If you have ever encountered any of these common mistakes, or if you're not sure what each of them means, consider working with a dimensional inspection lab with expertise in first article inspection. Getting production right the first time does not always happen in manufacturing, but getting first article inspection right the first time is not only possible, but also essential.

Q-PLUS Labs has the expertise and the equipment to inspect your first articles accurately and quickly so you can continue production or take the necessary steps to correct errors. We provide reports that are easy to interpret and offer custom solutions to any measurement application. Contact us today for a free assessment.

What problems do you encounter with first article inspections?

Color mapping is commonly used as a profile analysis tool in first article inspection primarily because it allows you to quickly visualize the differences between the scanned part and its nominal CAD model specifications. After an object is scanned, point cloud software highlights the differences using a color map. Each color represents a different degree of variation between the scanned part and the original design so that manufacturers are better able to understand what the part's actual condition is and refine and improve the corresponding manufacturing processes.

Color mapping is beneficial in many cases, but like any other technology, it does have some limitations. The key to effectively using color mapping for first article inspection is understanding these limitations and the applications for which it is best suited.

Color Mapping for First Article Inspection: Pros

• Ease of use - Color mapping allows you to use 3D scanning to get a big picture sense of how well the part conforms in one easy-to-understand visual display. At a glance, you can see areas where the part does not conform to the design and by how much.
  
  
• Flexibility - You have the freedom to control the color spectrum. If you want to see only the differences within a certain range of accuracy, you can adjust the display so that only those deviations are highlighted.
  
  
• Visibility - Color mapping can be conveyed in a number of ways. This includes free viewing software, dynamic HTML files, and 3D-interactive PDF files that allow you to move the 3D analysis result within it. This means that you can view the color map from multiple angles to get the most complete picture of the deviations on the entire part.

Color Mapping for First Article Inspection: Cons

• The dazzle effect - Undoubtedly, color mapping produces impressive results. However, a visually interesting result is not a certain indicator of measurement accuracy. Looks can be deceiving, and confirming accuracy is important, even when a colorful map seems to indicate good results.
  
  
• Inadequate data - Although color mapping is an effective way to determine where deviations are, it alone does not give you the hard data you need for process control. Further quantitative processing is required.
  
  
• Invalid analyses - 3D profile analyses are only valid when the specifications stipulate a profile callout. Inspections must still be performed in accordance with engineering requirements. In such cases, a 3D analysis serves only as a visual aid.

One perceived disadvantage of color mapping is that it is too subjective because you can't use it to compare across multiple parts. This is a myth. You can actually extract points for part comparison, turn off outside geometry, and take 2D sections. All these features allow you to objectively compare the deviations between multiple parts, allowing you to more effectively refine processes.

If you are interested in learning more about color mapping or any other dimensional inspection technology, work with the experts at Q-PLUS Labs or download our free guide to selecting the right dimensional inspection equipment.

Have you ever used color mapping for first article inspection? Tell us more about your experience in the comments section.