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  1. tim_member

    Fig 6-30/ ASME 2018

    In fig. 6-30, does the UOS profile apply to the 36 basic diameter? If not, what if the diameter needed to be additionally controlled with profile 0.5 to A|B? If in fig. 6-30 the profile tolerance applied to the 36 diameter had no datum feature references, would the UOS profile appply then?
  2. tim_member

    Composite tolerancing a multi-feature hole pattern

    cm_eng, If it's critical that each counterbore is controlled by its corresponding thru hole, then I don't think the approach you are trying to take is the best one, especially if the part requires extreme precision. I would recommend to control each counterbore relative to the corresponding...
  3. tim_member

    Circular Runout applied to a cylindrical surface defined with basic dims and profile control

    Are you asking about a scenario similar to Fig. 6-17 in '94?
  4. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    Yes, I was referring to the fact that the diameter of the tolerance zone to which the feature axis must conform could be negative. This simply shouldn't let anyone think that the actual value for axis interpretation is not determinable.
  5. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    Okay, I admit that the most recent example I made up reveals some issues with the axis interpretation as defined in the math standard, but that still doesn't mean that finding the actual value (that is, the value that would immediately and meaningfully tell by how much the feature axis deviates...
  6. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    You're welcome. I would generally agree that "the most sensible definition of "actual value" is the one that allows direct comparison with the tolerance value", however I'm not sure it makes "determination of conformance very simple" and that "the tolerance is satisfied if and only if the...
  7. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    ...There simply can't be negative actual value because the smallest possible value is 0 (when the UAME axis is perfectly at its true position). ******** (2) and (3) Knowing what the definition of actual value for axis interpretation says in para. 5.2.2 (c), I would say the values are not only...
  8. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    I have some questions: 1. If I am getting the formula correctly, it may produce a negative actual value. This would happen if, for example, a hole axis was perfectly oriented and located (D=0) and the hole UAME size was greater than the MMC size. The very last sentence of the paragraph for...
  9. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    This wasn't to provide a definition of simultaneous requirements, so let me try from another angle by using the following - maybe not too realistic - example: An inspector is told to evaluate the conformance of the feature from my illustration to the MMC MAX callout with the use of axis...
  10. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    Because it is a single callout applied to a single feature. Because 2009 standard doesn't say that for MMC and LMC callouts the surface interpretation is the default. It says that when the axis and surface interpretations give conflicting results (i.e., when one gives FAIL, while the other...
  11. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    I wasn't thinking about it this way. The picture below should help to clarify my point. My apologies that it shows external FOS rather than internal FOS as in Fig. 6-15. For the part as shown: - When both callouts are separate requirements, the measured perpendicularity value for the RFS...
  12. tim_member

    Fig. 6-15, para. 6.4.4 Y14.5-2009

    To nit-pick a bit, as long as '94 or '09 version of Y14.5 governs the drawing, the combination of position and two perpendicularities, as suggested by pylfrm, isn't technically identical with what is shown in Fig. 6-15. The perpendicularity tolerances are not subject to simultaneous requirement...
  13. tim_member

    Projected Tolerance Zone / Maximum Material Boundary

    Shortly speaking, the thicker the part the smaller the size of MMB of datum feature D. Thickness of the part matters because maximum material boundary of datum feature D resides inside the part (hole), not outside of it, and so its size (diameter) changes as the thickness of the part changes. I...
  14. tim_member

    Projected Tolerance Zone / Maximum Material Boundary

    I don't think this can be answered correctly without knowing the maximum possible thickness of the part. Also, cases 2(b) and 2(c) don't look OK. 3(a) and 4(a) should simply be 6.9.
  15. tim_member

    Profile Tolerance in General Note

    I am not sure what you mean by this sentence. What I meant, however, was that as long as the profile callout in the note is not clearly applied on the all-over basis (or it doesn't use any of the mechanisms mentioned in the pattern definition that I referred to), one can make an argument that...
  16. tim_member

    Profile Tolerance in General Note

    The problem with this example is that the general note (2) uses datumless profile and because of that it's not clear if the features subject to it are to be treated as a pattern or individually. That's probably why the quality inspector is raising concerns and suggesting to add ALL OVER to the...
  17. tim_member

    Counterbore control

    Flat surface of the counterbore is not a feature of size, therefore position FCF can't be even considered applicable to this kind of feature.
  18. tim_member

    Help with Positional Toleranceing for Symmetry

    Yes, that's what I am referring to and yes, I think that profile of a surface applied to both faces of the 50 mm width is the best choice. As soon as you start tolerancing other features of this part, that haven't been discussed here, you will notice even more how powerful profile tolerance...
  19. tim_member

    Help with Positional Toleranceing for Symmetry

    Y14.5-2018 gives a recipe for dealing with size specification for features of size that don't contain opposed points. See para. 5.8.1(e).
  20. tim_member

    Restraining Plastic Part

    If part geometry allows, some people would simply put four 0.5 kg weights over each datum target.

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