Belanger,
I would conclude from your statement that you have used rectangular locus for PLTZ. If so, was it accepted as legitimate. I have felt that an example in the standard would be of benefit.
I believe that the +/- for locating a pattern was replaced by the composite tolerancing scheme, in the 1982 version. My opinion was that they totally disregarded the benefits of a rectangular locus for the PLTZ.
I believe the method you describe was allowed prior to 1982. I also believe that it was 1982 Y14.5 that departed from the rectangular pattern locating tolerance zone to allow only the diametric. (I have been of the opinion that that was not well thought out.)
Without a date for the Standard...
Flash,
My thoughts are that you should re-examine the tolerances for the holes. They appear unnecessarily restrictive. I would also ask why the safety wire hole requires the use of a diametric positional tolerance in addition.
If you are using GD and T, Y14.5, and position the keyway with respect to only a primary and secondary datum feature, no specific orientation would be required, as I see it
To the best of my recollection, tangent was interpreted as having contact at a single point. Of course, that was years ago in a Geometry class in school. When did it get expanded to 3 points?
drawoh,
On one of your posts you suggest that a line may be used for clocking. Is that possible? I thought clocking (orientation) properly expressed should be to a point.
