3D Math Data, GD&T and FAI - My issue lies more with Profiles

[SArun Kumar]

The datum features "B" and "C" are features of size and have the Maximum Material Condition (MMC) symbol attached. This callout affects the manner in which the datums are utilized. A possible "datum shift" comes to mind. Have you taken this in consideration when programming your CMM or similar?

Any GD&T Covers who want to chime in?

Stijloor.

Hi Stijloor,

Actually i did programming in CMM in RFS condition. i am no looking for bonus tolerances. My doubt is how to state out of tolerance observation in report.
out of tolerance is -0.6737-0.40 = - 0.2737.
But when I am going making report against this (Profile 0.8 against Datums A /B /C)= 0.6737 it is OK.


Arun

 

[Paul F. Jackson]

But when I am going making report against this (Profile 0.8 against Datums A /B /C)= 0.6737 it is OK.
[/SIZE]

No Arun it is not OK to make it appear good by comparing the largest displacement + or - to the total zone specification... Report it as a deviation "Profile 0.8 (+/-0.4) is (+X.XX), (-0.6737)"

out of tolerance is -0.6737-0.40 = - 0.2737.
[/SIZE]

It is OK to report it like this... just make sure that the report clearly shows that the result is a deviation.

Paul

 

[SArun Kumar]

Dear Jackson & Paul,

Thanks for solving my problem.


I have another query related to Datum Directions (Pls refer attached Drawing file) as F/A , C/C and U /D. can anyone tell abbreviation of these as it is not available in ASME GD&T standard.

Regards
Arun Kumar

 

[Stijloor]

Dear Jackson & Paul,

Thanks for solving my problem.


I have another query related to Datum Directions (Pls refer attached Drawing file) as F/A , C/C and U /D. can anyone tell abbreviation of these as it is not available in ASME GD&T standard.

Regards
Arun Kumar

Arun,

I could only see a part of the drawing...or is it me?

Stijloor.

 

[SArun Kumar]

Yes Stijloor,

I was just a part of drawing. Now I have attached two whole drawings.
Pls review same.

Thanks & regards

Arun

 

[Stijloor]

Dear Jackson & Paul,

Thanks for solving my problem.


I have another query related to Datum Directions (Pls refer attached Drawing file) as F/A , C/C and U /D. can anyone tell abbreviation of these as it is not available in ASME GD&T standard.

Regards
Arun Kumar

The drawing has to be interpreted per ASME Y14.5M-1994 GM GD&T Addendum.

Do you have this document available at your site?

Stijloor.

 

[SArun Kumar]

OK Stijloor,

I am putting request to my customer for GM GD&T Addendum.

Thanks & Reagrds

Arun

 

[Frank T.]

How could i make observations report correctly?

SArun, this might be of some help, "(broken link removed)".

 

[Paul F. Jackson]

Doubling the worst deviation from the basic profile only works if the profile tolerance is specified "equal bilateral". If the profile tolerance is specified "unilateral" or "unequal bilateral" via illustration on the drawing describing how much is allowed in the material plus and minus directions then you cannot just double the worst deviation from basic profile.

Don Day's advice at the bottom of that Tec-Ease tip is probably the best advice "There isn't a standard on how to report profile variation. I recommend that companies prepare a one-page document that explains the method being used to avoid any confusion."

Paul

 

[SArun Kumar]

Thanks everybody,

Don Day's advice solved my problem.

Regards &
Arun