Fernando258
Automotive
- Jul 10, 2019
- 1
Hello everyone, we have a drawing from one of our customers of a Pipe Assembly (exhast components).
The assembly have 4 straight sections and 3 arc (bended) sections, this is a multiple axis bended pipe assembly. And in one of the straight sections (lets call it 'section #3') we have this dimension: '4X (∅88.9)' and attached to it has a Datum flag.
I ask the customer for clarification since there is a FCF of Concentricity in another component that joins the 2 pipes that make up the assembly, since these elements are not aligned (are not coaxial) to the straight section that has the Datum flag on it (lets call 'section #2' where FCF is attached). And the customer answer was that 'the Datum consists of the four straight pipe segment', for the moment I just take this as 'GO' to consider the straight section #2 as the reference Datum to report the concentricity, but is the argument that our customer says even valid? Could a multiple non-coaxial axis be taken as the same datum (together or individually)? (Just to clarify, 'INDIVIDUALLY' note was not added to the mentioned datum).
In the time that I've been working here I have seen some 'strange' GD&T practices from our customers but haven't seen something like this before.
The assembly have 4 straight sections and 3 arc (bended) sections, this is a multiple axis bended pipe assembly. And in one of the straight sections (lets call it 'section #3') we have this dimension: '4X (∅88.9)' and attached to it has a Datum flag.
I ask the customer for clarification since there is a FCF of Concentricity in another component that joins the 2 pipes that make up the assembly, since these elements are not aligned (are not coaxial) to the straight section that has the Datum flag on it (lets call 'section #2' where FCF is attached). And the customer answer was that 'the Datum consists of the four straight pipe segment', for the moment I just take this as 'GO' to consider the straight section #2 as the reference Datum to report the concentricity, but is the argument that our customer says even valid? Could a multiple non-coaxial axis be taken as the same datum (together or individually)? (Just to clarify, 'INDIVIDUALLY' note was not added to the mentioned datum).
In the time that I've been working here I have seen some 'strange' GD&T practices from our customers but haven't seen something like this before.