M3 RENISHAW, cylinder styli, ruby cylinder, ceramic shaft

Cylindrical styli measure two-dimensionally and are particularly suitable for narrow workpieces, such as thin sheet metal. Even narrow workpiece edges can be measured well with cylindrical styli. Care must be taken to ensure that the styli axis is mechanically aligned very precisely with the feature axis on the workpiece.
Ceramic shafts offer high stiffness with low weight and are therefore particularly recommended for long stylus shafts where weight and a high stiffness is a critical factor. The straight shaft is the simplest stylus design and the one with the longest usable length. The full shaft length can be used as measuring length. Ceramic shafts have a high rigidity, but are also very fragile. In thermal behavior and weight, they are worse than carbon fiber

Ruby styli are the standard for almost all applications and are available in a variety of different diameters. By scanning certain materials and surfaces, Ruby shows weaknesses due to material deposits and wear. With extremely soft materials, e.g. aluminum, material from the workpiece can be deposited on the ruby surface (material deposit). Very hard and rough surfaces, e.g. castings, on the other hand, cause abrasion of the sphere (material removal). The shape of the cylinder changes as a result and loses accuracy.