CMMs typically operate either by physically touching the object with the tip of a touch probe (contact method) or by measuring without touching the object, such as with lasers (non-contact method). Both methods have their unique characteristics and applications.
Contact Type CMMs typically use a touch probe to measure three-dimensional coordinates and dimensions through physical contact with the object. These machines come in various sizes and degrees of precision. Over time, traditional bridge-type CMMs have evolved into highly efficient and intuitive handheld CMMs which can be used anytime, anywhere.
The contact type CMMs record the center coordinates of the sphere at the tip of the probe when it touches the object. Using these collection of coordinates, they calculate the measurements. This method allows for flexible and precise measurements and is particularly effective for measuring complex shapes and three-dimensional objects. A significant advantage of contact type CMMs is their ability to measure quickly and consistently. However, one potential drawback is that larger bridge-type CMMs can require significant space and installation costs.
Here, we introduce four CMMs: GLOBAL Touch+ (Hexagon Metrology), ZEISS DuraMax (Carl Zeiss), XM Series, WM Series (Keyence). These machines are recommended for companies considering the implementation of contact CMMs.
Unlike contact methods, non-contact measuring machines project lasers or patterns onto object to measure three-dimensional coordinates and dimensions. They employ lasers or light to read the coordinates, generating a large amount of point or voxel data during scanning.
The primary advantage of non-contact measuring machines is the ability to quickly gather extensive measurement data without physically touching the objects. However, there are limitations, such as the inability to measure objects with shapes or materials that do not reflect light. Another downside is that the measurement range can be relatively narrow.
Non-contact measuring machines are particularly sought after in situations where even minor scratches on the object are unacceptable. With recent advancements in lens accuracy, sensor capabilities, and software convenience, these machines are increasingly in demand, even in environments requiring high precision.
