Mahr’s non-contact MarScope measures complex turned parts in seconds

The MarScope from Mahr UK is capable of measuring turned parts up to 1 m long by 120 mm diameter and weighing up to 30 kg. The unit, intended for both laboratory and shopfloor use, features a telecentric precision optical system with a high resolution camera that enables measurements of various characteristics to be made quickly and without contact.

Characteristics that can be measured include lengths, intersections, run-out, roundness, part axis, pitch, diameters, radius, co-axiality, concentricity, taper length, radius centre and widths of recesses or chamfers. A zoom function enables the measurement of small details such as bevels or small recesses that can be beyond the capability of traditional tactile systems. The part to be measured is mounted vertically between centres or special fixtures. When the fully automatic measuring sequence is initiated, the camera located on the measuring carriage scans the part, acquiring millions of points every second. Measuring value resolution is up to 0.0001 mm and angles up to 0.0001°. Repeatability is 1.5 µm (length) and 1.0 µm diameter on clean, polished workpiece surfaces. Tactile measuring device The MarScope can also be equipped with a tactile measuring device incorporating an inductive measuring probe that can be used to calculate flatness and squareness. The probe tip can be calibrated to the optical measuring system, and rotated by 90° in its length axis to enable tracing in Z and X directions in diverse measuring tasks. The MarScope measuring sequence is controlled through an easy-to-use graphical interface. Characteristics to be measured are indicated, and nominal values and tolerances entered and saved as a quality control plan. An optional software routine for thread measurement enables features such as flank diameter, flank angle and pitch to be included in the measuring sequence. The emphasis on fully automated measurement eliminates operator influence from the measurement results. Results are displayed on an LCD screen within seconds and can then be stored or printed out. The measurement printout is easily customised as required.