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Garland23 said:They just meant that each segment is verified without maintaining the requirements or constraints of the other segment.
Evan said:The second callout is not just a form refinement - it references A|B| and thus controls the orientation and location relative to both A and B.
Burunduk said:Yes, this is exactly how I interpret the axis control definition of an LMC tolerance in Y14.5. If recall correctly, the corresponding definition in the new Y14.45 standard on measurement data reporting is different because the "measured" versions of the feature axis and feature center plane changed relative to Y14.5 to be able to be produced from the "minimum material" envelopes for LMC-modified tolerances, so that the controlled element and the size considered for the bonus tolerance are to be determined from the same envelope depending on the material condition in which the tolerance applies. This is nice and makes sense functionally, but now there is a discrepancy between the standards. I could understand the logic of sticking with just the Unrelated AME, had the size used for the bonus calculation also been determined from it. It could allow inspection with pin gages. But I do understand your warning from relying on terminology too much.
That's true. I was kind of stuck with the idea that a bilateral equally disposed tolerance zone is always centered to a true profile, and so I imagined that if the tolerance zone expands or contracts it accompanies the same behavior of the true profile. It saved me the effort of making a few more circles and arcs in the sketches, but I ended up with an example that doesn't describe the problem accurately enough. Still, it doesn't change the substance of the point being discussed because the requirement of constrained location applies to the tolerance zone, and so if each curve is thought of two parallel curves, the example is still good at showing what I think to be the principally different results of applying the dynamic profile to the 2 types of features. The parallel arcs zone has shifted in location, while the coaxial cylinders zone did not. If the arcs didn't shift in location, does it mean that any element of circular shape, regardless of what portion of a 360° circle it constitutes, can only be located by the center of its radius?Evan said:One detail is that the true profile does not progress - it's the tolerance zone that progresses
Would the same be true if the toleranced feature was a planar feature instead of an arc, and the dynamic tolerance zone was progressing?Evan said:The zone is still constrained in translation, because we haven't allowed it to translate
I only see how it controls form, orientation and location like you initially said. It doesn't really control size because it can only limit the maximum value up to a maximum of 92.42+1/2=92.92 per the basic dimension from datum B and the profile tolerance value. But it doesn't control the minimum limit of size because the minimum surface-to-surface distance between the toleranced feature and datum feature B would depend on the form and orientation (relative to datum A) controls applied to datum feature B (not shown). So it is outside the scope of that 1 mm profile tolerance with ref. to datum features A and B. Controlling just one limit is not a size control. Do or do not. There is no try.Evan said:The lower callout controls a combination of size, form, orientation, and location.
Evan said:If we applied dynamic profile to a planar surface, I would still say that the zone is constrained in location because we haven't allowed it to translate. I know that this will be even more difficult to accept ;^). But I would also say that the end result of progression in this special case is identical to the end result of translation. So applying dynamic profile to a planar surface can get the same final result as applying a composite profile FRTZF
3DDave said:The progression is by definition - it is instructions to the person performing the task and is not inherent in the as-produced feature
3DDave said:2 + 2 = 4 = 2 * 2.
Does this special case mean addition is the same operation as multiplication?
Evan said:If the zone was calculated using a process that we are allowed to use, then that is sufficient. If there are other disallowed processes that would have obtained the same result, those don't negate the result from the allowed process.