The coordinate measuring machine (CMM) uses a solid granite-based table and a vertical-horizontal gantry to take measurements and compare them in blocks to an engineering file. The machine can only take measurements relative to previously determined coordinates. Using the two coordinates, the CMM generates 3D computer graphics.
Coordinate measuring machines allow manufacturers to perform dimensional measurements at nearly the same accuracy level as tactile probing. They also enable the operator to inspect surfaces within the shortest time. The CMM technique is limited to the measurement of relatively fewer points. In addition, the CMM is restricted by the probe’s top and geometry, meaning it is hard to use the machine to scan concave intersections.
Despite the limitations, CMM has various advantages and applications. Coordinate measuring machine laser scanners offer a perfect combination of ease of use, accuracy, and speed. The scanner takes advantage of CMM’s capabilities and its ability to digitize components quickly. Read on to find out why the method is still a reliable scanning method and where it is applied.
Benefits of CMM-based Laser Scanning
Coordinate measuring machine laser scanning is one of the most accurate ways of measuring an object. CMM’s capability has evolved with time and has increased the number of sensors. For a long time, manufacturers have wanted to mount laser scanners on new and existing machines. Using the coordinate measuring machine, a carriage for laser scanner enables the scanner to have a high accuracy positioning system.
The method is far better than optical-guided equipment or handheld portable arms that need a manual movement of a scanning device. The accuracy of a laser scanning machine without a camera or mechanical moving machine is around 10-30 micrometers. You must also include the uncertainty of the device used to position the laser scanner on the uncertainty of the laser scanner. Therefore, it is critical to utilize the most accurate positioning machine to achieve exceptional performance.
What’s more, a coordinate measuring machine eliminates the need for operator interventions when using the scanner. Consequently, repeated parts measurement does not result in fatigue of the operator, and they can do other tasks while the device is scanning.
When it comes to speeds, laser scanners have higher speeds than touch probe systems as they can handle thousands of points per second. With the CMM, you can measure small to large parts.
When CMM measures the overall dimensions, they are closer to the CAD design measurements than those given by 3D scanning. Therefore, the coordinate measuring machine has lower deviations.
Additionally, there are several sizes and styles of CMM allowing users to choose what suits their needs. The machines meet the industry standards, and they have certifications for measurement and software, so you are guaranteed the highest performance.
Plus, CMM-based laser scanners are ideal for surface and feature measurements on multi-material or reflective surfaces. The lasers also provide high-quality parts data for insightful comparison and reporting with CAD models.
There is an immense difference in the accuracy of a laser scanner and an analog scanning probe. Analog scanning probes have remarkable precision and repeatability. So, you cannot use a laser scanner for machine parts that need high precision unless you install it to coordinate the measuring machine.
Applications of CMM-based Laser Scanning
Many coordinate measuring machines manufacturers produce the devices with migratory paths for individuals wishing to install their laser scanners on the CMM. Older CMMs required the operator to change the controllers and buy news software with the capability of working with increased data load and graphical output when scanning complicated surfaces.
An individual would spend up to $50,000 to upgrade a scanner on a new coordinate measuring machine. When the overall costs of the new controller and software are considered, the expenses increase to $90,000. When integrating the laser scanner into a CMM, you should ensure that the tool changers can accommodate a wide range of probes to automate the measurements fully.
In addition, it will allow seamless exchange of tactile probes for laser probes during reverse-engineering without the intervention of a programmer. Modern CMMs can take complex measurements under the computer’s control and exchange information with CNC machines to control machining and achieve reverse engineering according to the measured data.
CMM–based laser scanning is used to measure machined components applied in aerospace, tool prototype, mechanical manufacturing, military, and automobile. Moreover, they are used in the furniture and molding industries. CMM-based laser scanners are an excellent option for industries handling objects with complex shapes, plenty of features, and high tolerances. These components include plastic, sheet metal, and castings.
CMM-based laser scanners are a timely boost to the traditional coordinate measuring machines since they offer higher accuracy, non-contact surface, and feature measurements with no need for art preparation. Also, an operator can maintain the functionality of the coordinate measuring machine while switching between the laser probe and touch probe.