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  1. PaulJackson

    How to specify dowel pin locations

    Kego, I don't know what type of joint you are designing but there are many designs that incorporate two round dowels and two round dowel holes. Almost every coupling where axes on either side of a housing joint must align (where alignment is not provided by the components alone) use two round...
  2. PaulJackson

    Can indirect control override direct one?

    I have no knowledge of the recent exchange so I'll enter the water calmly. Roundness is form only so the axis it is compared to is its own... I choose a) 0.05 I would re-word the comment "As we all know, Runout indirectly controls Roundness." Since a perfect roundness can have a imperfect...
  3. PaulJackson

    Rotating datum feature to align to axis

    If [A], [B], & [C] Orient, Locate, and Stop rotation of the part respectively in their assembled condition ... and the material edge location is dependent upon the DRF [A|B|C] then it is fitting that the origin is at the intersection [A] and [B] and oriented for rotation to [C]. The DRF does not...
  4. PaulJackson

    Rotating datum feature to align to axis

    Oh the stuff you see after you post! The angle should be 56.31 degrees rather than 60 among other things for that detail to work ... Paul
  5. PaulJackson

    Rotating datum feature to align to axis

    updated alternate Paulhttp://files.engineering.com/getfile.aspx?folder=1df91ebf-a5ba-472d-8876-e8810e140b0f&file=Alternate1.pdf
  6. PaulJackson

    Two datums adequate?

    Any discussion of how it should be tolerance should beg the question "how does it function... what orients and/or locates what... what tolerance liberties and refinements are necessary for ideal function?" If the flatness and perpendicularity were extracted leaving just the profile all over...
  7. PaulJackson

    Two datums adequate?

    This tolerances the remainder. Paulhttp://files.engineering.com/getfile.aspx?folder=7ffc38f3-8c1c-4cdc-99a9-659612f7cfa4&file=profile_examplePJ.pdf
  8. PaulJackson

    Datums call out @ part center is correct?

    Here is a functionally blind option. Paulhttp://files.engineering.com/getfile.aspx?folder=3cbedd80-1b11-4c52-8b8e-8964fa872efa&file=OPTION-Z.pdf
  9. PaulJackson

    Name for Other Zone

    "O" zone... aka "OTOL"
  10. PaulJackson

    needhelp with composite box

    should be... examine what wins in constraining the three rotation and three translational Degrees-Of-Freedom for the part you are detailing in the assembly or function.
  11. PaulJackson

    needhelp with composite box

    pmarc, Clamp load(maybe 800+ Kg)assisted by shank clearance maybe 3/4 MM all around... Just guessing... In ronj100's clevis the translation along the axis may actually be a width with clearance or it may have some sort of gravity assisted ramp for self closing... I don't Know!!! That clevis...
  12. PaulJackson

    needhelp with composite box

    pmark, You are correct he didn't specify... I said "may have" not "are"(were) and I will stick with my functional assessment. I believe as I have said before get the datums right first and the rest will fall in place.
  13. PaulJackson

    needhelp with composite box

    ronj100 See slide 3 for a possible solution. I believe you may have your datum features mixed up for their functional influence on the assembly. Functionally I don't think that the shoulder surface can arrest the two rotational degrees-of-freedom away from the long perpendicular cylinder...
  14. PaulJackson

    GD&T Callout to Protect Wall Thickness in Valve Housing

    jimbod20, you said: WHY MMC! Is there any functional purpose to permit the ten tolerance zones (projecting radially, equally spaced, and perpendicular to the primary datum feature's axis) to translate at minimum or translate and rotate away from that axis variably according to their size? I...
  15. PaulJackson

    REAL life example of LMC use.

    Supergee, Think of an engine head gasket... the cooling and lubrication holes in the block and head that pass fluids through the gasket as well as those gasket holes should have their tightest constraint functionally at LMC... while the head bolt holes and perhaps the dowel pattern spread...
  16. PaulJackson

    Pattern hole position

    Well done Evan... your attention to detail is showing! Now if we only had the feature sizes we would re-optimize and predict the precise amount of slop that the attribute gage could split in any given vector...
  17. PaulJackson

    Pattern hole position

    SeasonLee, Attached is 1) your pattern un-fitted (referenced from the center of the pattern)and 2) your pattern hand fitted (by eye) by rotating and translating the basic pattern and its known individual tolerance zones over a map of your measurements. Of course all of the tolerance zones are...
  18. PaulJackson

    Pattern hole position

    Yes you are correct the sizes of #1 and #3 are switched around. Sorry I never caught that mistake thank-you. Paul
  19. PaulJackson

    Pattern hole position

    PMARC, It is the difference between the individual feature’s MMC size and its pattern constrained oriented actual mating size as the collective pattern is simultaneously expanded/contracted among the pattern features until expansion is limited by at least one feature, then sequentially...
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