Overriding the Envelope Requirement is ISO
Overriding the Envelope Requirement is ISO
(OP)
If I have a drawing where the envelope requirement is made the default by a general note, reference to ISO 2768...-E, or other means, and I want to override the envelope requirement and have the independency principle apply to one feature of size on the drawing, how would I do that? The "I" symbol is not recognized by ISO. I was thinking I could specify a straightness tolerance with a value greater than the size tolerance, but why would that override the envelope requirement?
Any suggestions for overriding the envelope requirement in these cases? I don't want to use notes as these drawings may be used anywhere in the world.
Any suggestions for overriding the envelope requirement in these cases? I don't want to use notes as these drawings may be used anywhere in the world.





RE: Overriding the Envelope Requirement is ISO
I already said how this can be done in the other thread.
RE: Overriding the Envelope Requirement is ISO
RE: Overriding the Envelope Requirement is ISO
ISO 2768 only applies to dimensions without tolerances.
Add tolerance to your "feature of size" and you are good to go.
RE: Overriding the Envelope Requirement is ISO
Adding tolerance to a feature of size dimension will not solve the problem OP is having. If the print invokes Envelope Principle as a default condition, the tolerances itself will not bring Independency Rule into play.
RE: Overriding the Envelope Requirement is ISO
Well,
OP explicitly mentioned 2768 "or other means" so I tried to assure him that 2768 is the least of his problems.
To be honest my mind is blown by the idea of investing into ISO conversion, then immediately overriding fundamental ISO principles by invoking Envelope principle by default, then immediately starting to look for the way to override the override.
I guess, I got confused.
RE: Overriding the Envelope Requirement is ISO
RE: Overriding the Envelope Requirement is ISO
Sure, blame the ISO.
For me it looks like typical Checker-speak: "Let the drawing say ISO, but everything else should stay the same".
I actually have simpler solution for that: ISO provides modifier AD in oval frame meaning something like "'Alternative Default".
Just add something like this to the title block: "Tolerancing ISO 14405 (AD) ASME 14.5-2009" and forget about ISO forever.