![]() ![]() If the groove is parallel to A and is a circular feature located in an off center bore hole that runs perpendicular to A:ĭeviationA=actual-nominal of distance from A surface to grooveĭeviationB=actual-nominal of distance from centerpoint of circular groove to center point of the ODĭeviationC=(max-min)/2 depth of groove (probably unnecessarily complicated but the depth only actually should be checked in two directions since some error in groove depth is in the same direction as the B deviation and already accounted for: draw a line from center point OD, to center point bore hole, draw a 2nd line perpendicular to the first line through the centerpoint of the bore hole. Click Geometry tab > GD&T panel > Location > True Position. To create a GD&T True Position item: Open a Geometric group in the inspection sequence. The ideal location or true position of the hole is specified as 10.0 from datum B and 5.0 from datum C. of position of the hole, for instance, the center of the hole, to which the line from it points. From a thought experiment standpoint, think of the datums as what holds the part in place, and the position value is how far away from the location of the perfect part. True position reports the location of a feature relative to specified datum planes or axes. It also contains the line identifying datum B the one through the center of the hole denoted by B. Is the groove parallel to the A surface? Also how is the bore hole (C) positioned relative to OD (off center but the axis are parallel? I use a CMM to check position back to 3 datums all the time. ![]() Following the logic of using slots, this feature has the highest tolerances. The application of the callout is broad, used to control a varying array of features to their respective datum reference frames. The tolerance zone controls both location and orientation of a feature. The length horizontal dimension of the slot: This has a feature size tolerance of 0.5 mm and a position tolerance of 0.8 mm at MMC with respect to datum reference frame ABC. A true position callout defines a zone where an axis or center plane of a feature can vary from a theoretical exact true position. With real, imperfect measured parts none of the datum features will be exactly true to nominal, or perpendicular / parallel to each other. The GD&T true position shows the position in the datum scheme used for the GD&T. Can you share the print? It would be a lot easier with that. That gives us: True Position 2 x SQRT 0.00152 0.00152 0.004243. The labelled callout on the screen shows the position in the current active alignment. Formula for taper angle - Manufacturing Processes - 1. ![]()
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