Can anyone give me a practical explanation for RUNOUT GD&T?
3 Answers
Circular Runout:
Circular Runout zone is limited in the measuring plane perpendicular to the axis by two concentric circles, the common centre of which lies on the datum axis. Also it is can be defined as two-dimensional geometric tolerance that controls the form, orientation, and location of multiple cross sections of a cylindrical part as it rotates. For circular runout, the tolerance zone for each cicular element on a surface constructed at right angle to the datum axis. The circular element through a surface point conforms to the circular runout tolerance for a given mating surface if all points of the circular element lie down within some circular runout tolerance zone. Circular run out controls the cumulative variation of circularity (roundness) and coaxiallity for features constructed around a datum axis and circular elements of a surface constructed an angle not parallel to the datum axis. A circular runout tolerance. The tolerance zone is an annular surface of revolution about the center axis of the circle and perpendicular to the feature surface. FIM means, Full Indicator Movement.
At shown measuring position, each circular element of the shown surfaces must be within the specified runout tolerance which is 0.003 full indicator movement. when the part is rotated 360 degree about the datum axis with the indicator fixed in a position normal to the true geometric shape. The indicated surfaces must be within specified tolerance limit.
Total Runout:
Total runout involves tolerance control along the entire length of, and between, two imaginary cylinders, not just at cross sections. Total run out controls the entire surface simultaneously hence it controls cumulative variations in circularity, coaxiality, straightness, taper, angularity, and profile of a surface. Total runout tolerance for a surface constructed at right angles to the datum axis specifies that all points of the surface must lie in a zone bounded by two parallel plains perpendicular to the datum axis. And it is separated by specified tolerance. A total runout tolerance. The tolerance zone is an annular cylindrical volume of revolution about the center axis of the circle and concentric with the feature surface.
The specified entire surface of the part must lie within specified runout tolerance zone which is 0.001 full indicator movement. When the part is rotated 360 degree about the datum axis with the indicator placed at all the location alongthe specified in a position normal to the true geometricshape without reseting of the indicator. The feature must be within specified tolerance limit.