If you’re involved in manufacturing, you know that quality control is the name of the game and that precision is paramount.
And how is that precision achieved? For many manufacturing companies, manual inspection tools that have been around for decades (or even centuries), like calipers and gauges, are still used to judge the precision of their products. For others, traditional free-standing, hand-head, or portable Coordinate Measuring Machines (CMMs) are used. These machines measure the geometry of physical objects by sensing discrete points on the surface of the object using a probe of some type, either mechanical, optical, laser, or white light. The probe position can be manually controlled by an operator or, in more sophisticated machines, is computer-controlled.
These CMMs have proven to be reliable for the last 60 years or so, first appearing in 1959 and representing a huge improvement over hand measurements. Still, technology continues to improve and now more and more companies are looking towards 3D handheld scanners for their quality control needs.
While CMMs are still reliable and certainly still owned and used by many, there are a number of reasons why the switch to a 3D scanner might be a reasonable alternative.
The advantages of 3D scanners
- High accuracy – Many manufacturing operations make parts with fairly flexible precision. For example, a standard precision might be set at somewhere around +/-.005”. They could be more precise, if desired, and a 3D scanner can make that happen. While 3D scanners vary in accuracy, often according to features and price, many are accurate within +/-0.001” for small parts. While some manufacturers don’t require this degree of accuracy, others do, including the ever-growing aerospace industry. This degree of precision and accuracy makes the 3D scanner ideal for situations such as injection moldings and metal or plastic extrusion.
- Better inspection with more points – A handheld 3D scanner offers a much more detailed inspection because it gathers information from literally thousands of points on the object. And it does that quite quickly. In contrast, the CMM uses a touch probe to gather those all-important measurements. That means collecting a single point requires the machine to move to a different position. So, the machine needs to keep moving around to take measurements, which is cumbersome and time consuming. Imagine how much time it would take a CMM to gather information from thousands of points! As a matter of fact, a scan with a CMM rarely takes less than about 20 minutes, depending on the size of the object.
- CMM programming time is eliminated – A program must be made for each part that is inspected on a traditional Coordinate Measuring Machine. In fact, it takes about five minutes or more of programming time for every feature that needs to be inspected. The program can be reused but the initial outlay of time can be quite hefty.
- Fixturing pieces can be expensive – Every time a part is to be measured with a CMM, it needs to be bolted down in some way. That’s because the Coordinate Measure Machine must make physical contact with the part every time it gathers a data point. That means if it’s not clamped down in some way or another, that contact could cause the part to move and measurements would not be accurate. In addition, the need to “fixture” pieces costs precious time as well. Furthermore, complex or unusually-shaped parts often require their own custom fixturing solution, which will need to be made in the company’s machine shop or by an outside vendor. All of this can be eliminated by using a 3D scanner instead.
- Measurement of more challenging criteria – Manufacturing companies often report that the hardest aspects of a part to measure include flatness and concentricity. 3D scanning does both quite well and far better than the CMM.
If you own or manage a company that’s used CMMs or even manual measuring tools for years and are hesitant to make the switch to a handheld or other 3D scanner, let us tell you more about how these technologically-advanced devices can save you both time and money. For more information, call us at 604-910-0165.