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  1. semiond

    Rule #1 of Y14.5

    This is not as good as the sketches suggestion but I can try with words: You could look at the cross sections not as on circular areas but as lines in a view where you see whole length of the pin. If the pin is bent and you look at the middle of it, you will notice that the start point of the...
  2. semiond

    Rule #1 of Y14.5

    greenimi, The most simple answer to the question "how" would be: Indirectly, but inevitably. The more comprehensive answer you can provide yourself by making a couple of sketches, rembemring that the longtidual and the cross sectional areas belong to the same piece of solid material :-)
  3. semiond

    Rule #1 of Y14.5

    greenimi, If I understand correctly your question, the answer might lie here: Para 2.7.1: "(b) Where the actual local size of a regular feature of size has departed from MMC toward LMC, a local variation in form is allowed equal to the amount of such departure." I think this is pretty...
  4. semiond

    Controlling "sharp" edges through geometrical controls

    By round cutters you probably mean form milling cutters, not lathe tools. Those are not different in principle. The face under the cutting edge (flank) is gradually tilted away from the workpiece by the means of a relief/clearance angle ground on the tool/toolbit. It could be a flat face or a...
  5. semiond

    Rule #1 of Y14.5

    OmarEn07, I would word a conclusion otherwise: Rule #1 applies to regular features of size with the exceptions noted in the Y14.5 standard. One sided tolerancing isn't recommended for cylindrical features, because of poor product definition.
  6. semiond

    Rule #1 of Y14.5

    powerhound, You're talking about the wrong pin. greenimi's pin has a minimum limit. The one that hasn't is 10mm Max.
  7. semiond

    Rule #1 of Y14.5

    No portion of the pin will be allowed to violate a boundary of a perfect form cylinder of 10mm diamter size. Perferct form at LMC is not required, but you still need to specify a minimum diameter limit to fully define the part, and it's form. Otherwise, if there is no Min. limit, you could make...
  8. semiond

    Controlling "sharp" edges through geometrical controls

    3DDave, If you propose a dimensioning scheme where the rake and the flank surfaces will be defined, each one, in a view where it appears as a contoured surface with each line element along it parallel to the projection view, you will find that there is no such view available. Because of...
  9. semiond

    Controlling "sharp" edges through geometrical controls

    When you said that you would use profile to control the perimeter, I thought you were referring to a view where the edge is part of that "perimeter" (where the edge is viewed as a line). If by controlling a "perimeter" you mean controlling the outline of the cross section with profile, like I...
  10. semiond

    Controlling "sharp" edges through geometrical controls

    The reason why the word "sharp" is in apostrophes in the title, is that no real edges are completely sharp as in a theoretical intersection of two planes(not surfaces) - these things only exist in theory, and in drawings, where edges are depicted as lines and do not represent something with an...
  11. semiond

    Controlling "sharp" edges through geometrical controls

    3DDave, With the dimensioning scheme you described, I suppose you were referring to the example I presented to drawoh (the sculpture knife). I have to admit that my experience is not in dealing with this specific kind of products, but if I can rely on my knowledge from the metal cutting tools...
  12. semiond

    Combined Controls Extension

    pmarc, Regarding the level 1/2: I can justify aspiration to get to level 2, as long as what it takes to be at level 2 doesn't come in expense of the main goals of the strategy of level 1 which you described: "fully and unambigously define product". With modern production equipment, many...
  13. semiond

    Combined Controls Extension

    greenimi, I appreciate your second quote very much - that was said much better than I could ever say to express my message. But please allow me to use your first quote with a little modification - I will replace just one word by a one that is closely related to it and more relevant to this...
  14. semiond

    Combined Controls Extension

    I just want to add to pmarc's last remark my observation, that Level 2 is only available to "design players" working in organizations where the people "playing" at the production floor have enough spare time at their work day to interpret sophisticated feature control frames using colourful...
  15. semiond

    Controlling "sharp" edges through geometrical controls

    drawoh, You probably remember the example I showed you in this thread a while back (the sculpture knife) you told me how you would choose the datums but I'm still waiting for your suggestion on how to specify the feature control frames to define the cutting edge geometry (angle and location) The...
  16. semiond

    Combined Controls Extension

    pmarc, I do understand the point that you convey with the rethorical questions. But please notice that I emphasized the words "in this particular case" in my last post. I learned to never make generalizations, unless those generalizations are narrow enough to describe a very unique type of...
  17. semiond

    Combined Controls Extension

    pmarc, I looked at your diagrams once again. We calculated the same MMB (VC) and LMB (RC) boundaries that appear to be equivalent for both controls. Yes, I know the rotation phenomenon for the profile+position combo makes a difference and widens the LMB boundary in a peculiar way, but it didn't...
  18. semiond

    Combined Controls Extension

    pmarc, I agree with almost everything said, And by the way, I too don't like "position wrt A applied to a single feature of size that is nominally perpendicular to datum A." Why not use perpendicularity? However you mentioned that MMC position + profile combo vs. composite profile that we...
  19. semiond

    Combined Controls Extension

    pmarc, Regarding your answer to chez311 - we've seen that the composite profile tolerance, in terms of tolerance zones, provided the same flexibility for production as the profile+ MMC position with it's bonus. That is with the additional advantage of design intent clarity and less "unexpected"...
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