M2 and M3 Renishaw Styli and Accessories

A few simple rules can be applied to maximize the accuracy for most probing applications.

A = ball diameter

B – Overall Length

Renishaw uses a standard description of overall length, measured from the rear mounting face of the stylus to the center of the ball.

C = stem diameter

D – Effective Working Length (EWL)

This is measured from the center of the ball to the point at which the stem will contact the feature when measuring ‘normal’ to the part.

EWL can also be affected by assembly tolerances. For this reason Renishaw styli are assembled to exacting standards in controlled conditions.

Description

Rules for choosing the correct stylus

A few simple rules for stylus selection can be applied to maximize accuracy for most probing applications.

Keep styli short

The more the stylus bends or deflects, the lower the accuracy. Probing with the minimum stylus length for your application is the best option.

Minimize joints

Every time you join styli and extensions, you introduce potential bending and deflection points. Try to keep to the minimum number of pieces possible for your application.

Keep the stylus ball as large as possible

There are several reasons for this:

Maximises your ball/stem clearance, thereby reducing the chance of false triggers caused by ‘shanking out’ on the stylus stem, and increasing the EWL.
A larger ball allows a larger stem diameter, increasing the stiffness of the stylus.
A larger ruby ball reduces the effect of the surface finish of the component being inspected.