Drawing Technique

[Downeyman]

I have been using "CENTER" OR "CENTERED" for quite some time when describing a feature cnetered about a axis or hole pattern. A senior level engineer questioned my use and had never heard of using "CENTER" as a dimensioning technique. Has anyone else used "CENTER" before and what is your interpretation of the tolerance stack-up?

Heavy D

 

[dr_gallup]

True Position is the current preferred GD&T but I still like to use Symmetry in cases like that. It just seems so much more intuitive when you have an obvious axis of symmetry as opposed to having implied basic dimensions of zero with True Position. But I would never just say CENTERED, how would you indicate the allowable deviation from perfect position & form?

 

[dross]

There is a text symbol in Pro for this.


It looks like three horizontal bars stacked above each other, the center one is longer than the top and bottom ones.

 

[sbiker]

I think using just the symbol without value isn't proper.
This symbol is supposed to be used as geometric tolerance
with value which gives the symmetry "quality" of toleranced
feature - here is "princip" of symmetry geometric
tolerance:
View attachment 5722

 

[sbiker]

still a brief description:
SYMMETRICAL FEATURES: USE SYMMETRY FOR
NON COAXIAL PARTS WHERE BALANCE IS
IMPORTANT. (NOTE: EXCEPT FOR THE SHAPE OF
THE PART SYMMETRY AND CONCENTRICITY ARE
IDENTICAL, AND THE CAUTION EXPRESSED FOR
CONCENTRICITY APPLIES HERE AS WELL.
CONSIDER USING POSITION.)
(http://www.draftingzone.com/shoppingzone/dmpgt.pdf)

 

[dross]

I think using just the symbol without value isn't proper.
This symbol is supposed to be used as geometric tolerance
with value which gives the symmetry "quality" of toleranced
feature - here is "princip" of symmetry geometric
tolerance:
View attachment 5723

The way that you show it is correct per ISO 1101.