3D Model Call Outs.

[Valek]

Hello,
As we all know the BoM usually mentioned that the dim- that are not given on a dwg resides on the CAD model.

I have a situation that drawings are per the ISO std (which do not call for composite tol- & do not have datums on the dwg) and have missing in this case the Y basics dim- for hole location, it gives you only the basic for the X loc-.

This supplier of ours is in the process of submiting FAI's per the AS9102 std using Net-Inspect. And in form 3 of Net the supplier is not accounting for the Y basic dimension for hole loc- which is on the model.
I keep rejecting these FAI's because of this and the nonsense answer from the supplier is that they don't have to submited if is not on the dwg-. I keep telling them that they have to interrogate the model to find this dim- and they shall included on form 3, otherwise the FAI's would be incomplete.

Does anybody agreed with this statement?
Thank you.

 

[powerhound]

If I understand what you're asking then I would have to disagree with you. You start out with "As we all know..."

Do we?

Apparently not.

I think your supplier has a point. If you have a drawing and you want a certain dimension, then why isn't that dimension on it? To your point, I think your supplier should not be argumentative and just provide the information you are asking for. Unless there's more to this story than you're giving, I think it's as simple as that.

Powerhound, GDTP S-0731
Engineering Technician
Inventor 2013
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[CheckerHater]

Valek,

If I understood you correctly,

• You have a model that you consider “basic” and therefore you believe all necessary dimensions can be derived from the model.
• But you also have a drawing that has at least one dimension on it.
• Your supplier wants only control dimension(s) shown on the drawing.
• You are working to ISO

Guess what? If things are the way you describe, your supplier may be right!

According to ISO 8015-2011 Para. 5.3 Definitive drawing principle:

“The drawing is definitive. All specifications shall be indicated on the drawing using GPS symbology (with or without specification modifiers), associated default rules or special rules and references to related documentation, e.g. regional, national or company standards. Consequently, requirements not specified on the drawing cannot be enforced.”

 

[pmarc]

I am with powerhound and CH on this. You simply cannot enforce something which does not exist in the documentation in any form - note, reference to a standard, etc. That being said, if your print or any other document listed on the print does not mention anything about using CAD model for missing dimensions, your "as we all know..." thinking is just wishful.

There are of course implied basic 0 dimensions that do not have to be specified on the print, but as far as I understand your situation it is not the case here.

 

[weavedreamer]

If a drawing possessed a note like this:

UNLESS OTHERWISE SPECIFIED THE CAD
MATHEMATICAL DATA IS CONSIDERED MASTER
AND HAS ZERO TOLERANCE. FOR DIMENSIONS
NOT ON THE DRAWING, ANALYZE THE CAD MODEL.
ALL ASSUMPTIONS MUST BE APPROVED IN WRITING

in conjuction with an UNLESS OTHERWISE SPECIFIED, ALL OVER PROFILE X.XX|A|B|C
would this satisfy the ISO 8015-2011 Para. 5.3 Definitive drawing principle?
Would this approach be considered valid under ASME Y14.5M - 1994?

 

[CheckerHater]

Weavedreamer,
Even the best general notes usually fail to adequately control position.
Would you be comfortable with the note saying ALL HOLESS ARE DIA .010 WRT EVERYTHING or something like that?

 

[weavedreamer]

The drawing generally have all the machined holes identified and located as required. The note was something intended to apply to undimensioned cast surfaces on complex parts.
If cast holes, or features are dimensioned on the print, the dimension on the print, is inteneded to override the generic 'profile' and 'cad mathematical data' notes.