ANSI Y14.5 dimensioning in Quindos

By default QUINDOS is ISO only. There is no "switch" that I know of to toggle between ISO and ASME like there is with other software - like PC-Dmis for example. Having said that, ISO and ASME have essentially the same interpretation for most things and only really differ for the likes of profile, symmetry and concentricity / coaxiallity so I assume you would have to "code your way" around those differences - QUINDOS has the tools to allow you to do practically anything you want to, in what ever way you want to do it.

Thanks, Neil.

I will be checking lots of concentricity, coaxiality and runouts, do you have examples of code?

Unfortunately, no, I don't have any example code. You may have more luck contacting one of the American applications teams since I assume it's a problem they will have run into.

By default QUINDOS is ISO only. There is no "switch" that I know of to toggle between ISO and ASME like there is with other software - like PC-Dmis for example. Having said that, ISO and ASME have essentially the same interpretation for most things and only really differ for the likes of profile, symmetry and concentricity / coaxiallity so I assume you would have to "code your way" around those differences - QUINDOS has the tools to allow you to do practically anything you want to, in what ever way you want to do it.

If only! I mean the fact that they both used the same symbol (Concentricity) to mean different things is confusing enough, but the common misconception that the difference between the two languages are few is even worse.

Fortunately in the latest release ASME Y14.5-2018 no longer supports Concentricity (YIPPEEE!!!!!). And it bears pointing out that ANSI only certifies the standard these days, it does not author nor publish and therefore the proper title is ASME 14.5 not ANSI Y14.5.

I am no expert on ISO GD&T but to the best of my knowledge it is possible to do most things in either language, but it's the exact phrasing that gets sticky. There are many subtle nuances to GD&T that must be observed.

The two languages differ in some key default conditions for fundamentals, including but not limited to The Taylor Principle which is known as Rule #1 in ASME and the Envelope Principle in ISO. In ASME it is the default condition, in ISO it must be invoked with the E in a circle symbol. Then there is Axis vs. Median Line. For many tolerances on cylindrical features, (e.g. position), ASME controls a straight line axis while ISO controls a median line of imperfect form. The final difference I will point out here is the ISO default of Independancy versus the ASME default Simultaneous Requirement.

I recommend Alex Krulikowski's 2010 book ISO Geomentrical Tolerancing. It is a good place to start to explore the differences between the two languages.

I have not read myself, but have on my to read list, Henrik Nielsen's 2012 ISO Geometrical Product Specifications Handbook.


HTH & ymmv

Sorry, you´re right, is ASME 14.5 not ANSI Y14.5, I don't know what the hell I was thinking.

The final difference I will point out here is the ISO default of Independancy versus the ASME default Simultaneous Requirement.[/FONT]

As far as I understand it, this difference is a difference in wording only - ISO says default is independancy, and then lists a lot of cases where it should be simultaneous (patterns around a common center point/axis, MMB on datums, etc.), so I think the final outcome is the same. ISO is independant only in those cases where simultaneously wouldn't change the result… I may be missing something, though…

There are also changes coming to ISO, to eliminate all defaults everything should be explicit on the print, but that will take a while before all prints are updated…

I also belive there is something about the (E), making it the default (in some cases?), but I don't have our standards expert available right now, and don't care for reading through umpty-eleven hundred pages again…

The only big difference, as I see it, is the definition of profile deviation - 2 x max(abs(MAX), abs(MIN)) instead of MAX - MIN. And in reality, they are both insufficient - you need to look at the MAX and MIN separately.