Let`s go study how to use an indicator head to determine the shape errors of cylindrical surfaces. You can see instruments and equipment below, which we need us.
Instruments and equipment: indicator head with a tripod, measuring parts, a set of final measures of length, other equipment.
Analyzing the accuracy of the geometric parameters of the cylindrical parts, there are distinguish between nominal sizes surfaces, that is, ideal ones and really surfaces ` sizes.
Deviation of the surface shape is the deviation of the shape of the real surface from the shape of the nominal surface.
There are such deviations of the shape cylindrical surfaces: in cross section – deviation from roundness, in the longitudinal – deviations of the profile of the longitudinal section.
There are also deviations from roundness such as ovality and
faceting.
Ovality – deviation from roundness at which the real profile is an oval-like figure, the largest and smallest diameters of which have mutually perpendicular directions.
Faceting – deviation from roundness is when the real profile is a multifaceted figure.
The deviation of the profile of the longitudinal section characterizes the deviation from the straightness and parallelism. Separate types of longitudinal section are cone-shape, barrel-shape and saddle-shape.
The estimate of the deviations of the cylindrical surfaces is calculated by the formula:
