ISO GPS - Line profile for a spine of a bent rod? 2

[Burunduk]

In thread1103-514448, at the last post of the thread, I saw this figure posted by Ryan and taken from ISO 1660. It surprised me a lot because I have never seen a diametric tolerance zone for profile of a line applied to a resolved geometry (spine?) of a feature of size (associated with the diameter dimension). I do not have a copy of ISO 1660, but I haven't found anything similar in ISO 1101-2017.

Is anyone here familiar with it and could maybe elaborate a bit about where exactly and how such a control is defined in the ISO GPS standards?

 

[Garland23]

I have never seen a diametric tolerance zone for profile of a line applied to a resolved geometry (spine?) of a feature of size (associated with the diameter dimension).

I work with ISO quite a bit, and I can say that I have never seen a diametric tolerance zone for profile at all, regardless of it being a spine, FOS, or any other thing.
I'm interested to hear a full explanation.

 

[greenimi]

And I already know who's opinion is needed here......
I am waiting for his valuable and pertinent views on the raised issue.

 

[3DDave]

https://www.ijmerr.com/uploadfile/2018/0613/20180613052716875.pdf

 

[greenimi]

. It surprised me a lot because I have never seen a diametric tolerance zone for profile of a line applied to a resolved geometry (spine?) of a feature of size (associated with the diameter dimension).

Per what I learn from people here on the forum which have more knowledge than I do in ISO GPS is that the characteristic that the profile applies to is pure cylindrical shape of the feature disregarding the size specification.

So this specification is applied to a derived feature and the integral feature does not need to be defined with TED's (diameter of the feature is plus-minus)

Maybe a question could be added: can we add MMR too?
I would think so.....then the geometrical tolerance would change from derived feature to a requirement applied to a surface feature....I guess.

 

[SeasonLee]

Burunduk

This is indeed a good question for people with an ASME background, I hadn't noticed that before. Just providing some of the relevant content of the standard, and I am also looking forward to further interpretation as mentioned by greenimi.

 

[Ryan6338]

In response to Burunduk's enquiry on where this type of control is defined - The example in Figure B.14 is a combination of a compound feature per ISO 1101 section 9.1.4 and the application of Rule C of ISO 1660 as posted above. The tolerance limits are a tube formed by an infinite series of spheres around the derived centreline of the compound feature.

Ryan.

 

[Burunduk]

SeanonLee and Ryan,
Thank you for your high quality answers.
As SeasonLee indicated, having mainly ASME background I will have to let it sink in.