What is a measuring needle?

What is a measuring needle?

The measuring needle is a part of the measuring system, and the contact with the workpiece to be measured results in the displacement of the probe mechanism. The measurement results are obtained by processing the generated signal. The appearance of the measured workpiece will determine the type and size of the measuring needle. In all cases it is important to measure the stiffness and sphericity of the needle. In principle, the measuring needle is the coordinate measuring machine. "Tool" is like the relationship between turning tool and lathe, milling cutter and boring cutter and milling machine. When measuring with a contact measuring head, the machine tool uses a measuring needle to collect data points on the workpiece surface. The points generated by each trigger are defined using X, YZ coordinate values. These points are then used to calculate features, size, shape and position. The difference is that the scanning measuring head collects continuous data points along the workpiece surface. Powerful software uses this data to calculate the size, position, and shape of features on the artifact.

Great care must be taken in selecting the measuring needle to ensure that the needle must be measured with great care and * suitable for your measuring application. This chapter describes the main types, key parameters and material properties of measuring needles and accessories. If you want to fully measure the workpiece on a coordinate measuring machine equipped with fixed sensors, you usually need a large number of measuring needles, which are mounted in different directions and require different shaped measuring needle assemblies, extension rods and joints. A combination of all these components, called a measuring needle configuration, is mounted on the transfer block. Renishaw produces a range of measuring needle assemblies in different materials, so you can match measuring needle configurations to meet measuring applications.

Straight measuring needle

Direct measuring needle is the most simple, most commonly used type of measuring needle. There are straight shoulder measuring rods and tapered measuring rods to choose from. When the workpiece is easily accessible, the measuring needle of the tapered measuring rod is more rigid. Measuring needle ball heads are made of ruby, silicon nitride, zirconia, ceramic or tungsten carbide. The ends and measuring rods are available in a range of materials - titanium, tungsten carbide, stainless steel, ceramic and carbon fiber.

Main Application: To avoid needle distortion, choose a short needle as far as possible, especially when using a trigger probe system.

Star needle measurement

A multi-tip needle configuration consisting of a securely mounted needle. The ball is made of ruby, silicon nitride or zirconia. It is also possible to install (* more than)5 needle measuring assemblies with a star needle measuring center seat.

Application: Surface and hole can be directly contacted. This configuration is flexible, the measuring tip can contact with different characteristics, no need to change the measuring needle.

Rotary needle measuring:

This is a clamping mechanism that adjusts the measuring needle to the desired Angle.

Main applications: For inclined plane and inclined hole, the configuration is flexible, the measuring tip can contact with different characteristics, no need to change the measuring needle.

Disk shape measuring needle

These measuring needles are high sphericity measuring ball "cross sections" available in a variety of diameters and thicknesses. The disc measuring needle is mounted on a bolt and is made of steel, ceramic or ruby. The omnidirectional rotary adjustment and center measuring needle function are features of the disc measuring needle series. This makes the measuring needle very flexible and easy to use.

Main applications:

The measuring needle is used to detect the cutting slot and groove in the hole that the star measuring needle cannot reach. Simple disk needle measurement. The "spherical edge" test is as valid as the test for or near the outer circle of a large-diameter ball. But only a small part of the surface of the ball can be touched, so in order to ensure good contact with the target to be measured, you need to adjust the Angle of the thin disk measuring needle.

Column needle measurement

The cylindrical needle is made of tungsten carbide, ruby or ceramic.

Main applications:

Used for measuring sheet metal, molded components and thin workpieces that cannot be accurately contacted by the spherical needle. It can also measure various thread characteristics and locate the center of the tapping hole. The ball-end column gauge is fully calibrated for X, Y, and Z direction measurements, so surface measurements can be made.

Ceramic hemispherical needle measuring:

The advantage is that the effective measuring ball diameter is large, the weight is small, using this large diameter measuring ball to measure the influence of uniform surface roughness.

● Main application: for measuring depth characteristics and holes. Because the roughness is mechanically filtered out by large diameter surfaces, it is also suitable for contact rough surfaces.