Surface roughness probe introduced by LK Metrology

CMM manufacturer LK Metrology, which has its manufacturing facility in Derbyshire, has  introduced its Surfacer SRP. The new Surfacer SRP is a plug-and-play probe with a resolution of 1 micron for analysing the roughness of a component’s surface as part of a CNC measuring cycle on any CMM, provided it has an industry-standard probe head.

The new sensor eliminates the need for secondary surface roughness inspection, either manually using a hand-held instrument or automatically at a separate metrology station. Manufacturers are able to conduct comprehensive inspection on a component in a single set-up in a CMM environment, generating savings in time and cost. Engineered for ease of use and versatility, the equipment comes with its own downloadable application software, facilitating integration and eliminating the need for third-party software.

Swapping between touch probes, tactile scanning probes, non-contact laser scanners and the roughness probe gives users extended multi-sensor capability. The Surfacer SRP mounting is compatible with change racks, including new versions introduced recently by LK, enabling automated sensor changing and enhanced operational efficiency.

At the heart of the roughness probe lies a special body that accommodates three interchangeable, skidded, stainless-steel probe modules. One evaluates flat, conical and cylindrical surfaces, while another measures concave, convex and spherical surfaces. A third is for inspecting grooves more than 3 mm wide by less than 10 mm deep, or steps of similar height.

The CMM positions a stylus to contact the part, after which the machine axes remain stationary while the probe moves the stylus across the surface under investigation. Wireless communication with the CMM computer via a Bluetooth 4.0 adapter provides seamless data transfer for analysis, simplifying installation.

The skid plays a key role during measurement, acting as a straight-line datum that guides the stylus across a surface to ensure probe stability. The stylus travels independently of and slightly in front of the skid, with surface deviations recorded as the difference in the relative movements of the two elements in the Z axis. The design ensures that even minute surface irregularities are captured with exceptional accuracy.

Further enhancing the precision of the Surfacer SRP is an integrated pre-load mechanism, which during stylus operation isolates it from the CMM kinematics, guaranteeing accurate and consistent results regardless of external vibration or machine movement. The force exerted by the stylus tip, which has a radius of 5 micron, is less than four thousandths of a Newton, avoiding surface deformation. Measurable roughness range is 0.5 to 6.5 Ra, which is the average roughness between the profile and the mean line.

Dave Robinson, LK’s marketing manager, says: “By integrating surface roughness measurement directly on to the CMM, we’re providing manufacturers with a powerful tool to streamline their inspection processes, reduce costs and enhance product quality. The ability to perform multiple metrology functions on a single platform eliminates the need for time-consuming transfers of components and ensures greater accuracy by maintaining part orientation between measurements.”