In designing and manufacturing, the ability to measure your results is very important. Quick, accurate, and repeatable measurement is the goal of every quality system. One issue that is widely experienced in the production environment is the ability to get the same result from operator to operator, especially with complex parts and small tolerances. The importance of having a good inspection systems is emphasized by the need for accuracy and speed. Early identification of issues allows for rapid responses to resolve critical issues.
The term “smart gauge” refers to an electronic inspection system that automates some or all of the inspection process. In this short article we will look over a few visual and physical smart inspection systems and talk about their strengths and weaknesses.
Physical Inspection Systems
Contracer: When you have a part with an unusual exterior shape it can be difficult to measure the distances and angles along the profile. This machine from Contracer can analyze outside features by tracing a needle over the part to create a profile. With this profile you can insert your tolerances to measure angles, tapers, distances, or even surface roughness. These profiles can be stored and used to compare against drawing and model dimensions. Cost: $45,000 USD.
Coordinate measuring machine (CMM): A CMM is able to check features on very complex parts by touching a probe to a programmed set of points around the outside of a part. While a CMM isn’t the easiest inspection system to program, it can make up for that by its ability to check multiple faces and difficult features on parts. It is also able to switch out probes mid inspection to check different features. Cost is $75,000 USD
Visual Inspection Systems
Instant Measurement System: Keyence’s Instant measurement system is a very fast way to inspect multiple profiles. The system has a top mounted camera and light system to take a quick profile of the available part. The IM system is able to look at multiple parts at once, comparing them all to the pre-programmed profile. It can then show all out-of-spec features and a listing of how far they are out. This system saves time by inspecting three or four parts in as many seconds. It is better for flat parts, as rounded ones will require fixture. Cost: $37,000
Oasis Elite: The Oasis visual system takes multiple part profiles from the side, measuring each feature while rotating the part. This gives a full 360 degree view of the part and allows the true points to be measured. The strong benefit is the ability to take thirty pictures in just five seconds. Results are averaged to get a good true reading of the features. With the rotary base the Oasis is great for round parts, but can also inspect square parts. Cost: $35,500 USD
Laser-Lab: The Laser-Lab is unique in the fact that it takes full 3-Dimensional scans of the manufactured parts compared to the CAD model of the part. While slower, it offers a full image of the inspected part and highlights all nonconforming areas, such as damage to threads or issues with roundness. Cost is $95,000 USD
While inspections are incredibly important, they can also carry a heavy cost. If every inspection is done by hand, then some quality checks can take several minutes for a more complicated part, or a series of parts. These systems all have a large cost to start, but they can pay benefits in early detection of variances in the manufacturing process and saved time. For the relatively simple parts an Oasis or Keyence system can go far for the cost. It is important to consider the needs of your company versus the associated cost. A recall or lost revenue could easily end up costing the more than some of these systems.