Name of ASME Document Governing "Dimensioning" 2

[ModulusCT]

I am constantly told by people I work with, who are quick to ponit out how much more experience than me they have, that ASME Y14.5-2009 is Geometric dimensioning AND TOLERANCING and not a document about how to be a drafter. I can sort of understand where they're coming from, but am of the opinion that they're totally wrong.

First of all, the document itself says that it supersedes all other specs cited within it, which includes the specs that supposedly govern 'drafting practices'. Seconly, I still haven't found any other document that explains that an angle must start from it's axis of rotation (this is what my checker tells me - this is a plastic, injection molded part), or that a dimension should always have the arrows inside when possible or that two adjacent dimensions should be offset, and not ever share an arrow.

Can anyone tell me which spec covers these things? Because in the past I've always relies on 14.5 and the examples within... Now I'm being told that it's insufficient and that only having knowledge of the 'old way' of drafting is going to be beneficial... or some garbage like that.

Anyway, which ASME spec tells you how to draft? I always thought it was a bunch of theory

Thanks!

I'm not a vegetarian because I dislike meat... I'm a vegetarian because I HATE plants!!

 

[ewh]

Y14.5 covers dimensioning as well as toleranceing, but not in the depth you are seeking. Supplement the standard by studying some Drafting text books for more insight as to what is being expected of you. The directions that you have been given are not "totally wrong" but are generally accepted good practice (though I disagree with offsetting adjacent dimensions). Ideally, these preferences would be documented in a Drafting Room Manual, but are more frequently tribal knowledge. Don't just look at the information being included on a drawing, but also look at how that info is being presented. The goal is to make the drawing complete, concise, easy to read and subject to only one interpretation.
Considering "knowledge of the 'old way' of drafting" as garbage is unfortunate.

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[CheckerHater]

Anyway, which ASME spec tells you how to draft? I always thought it was a bunch of theory

Here are some: faq1103-1039

 

[ModulusCT]

None of those specs, except 14.5-2009 actually describes how to dimension a part and what kind of dimensions are acceptable and in what manner they should be placed. According to some people here where I work though, 14.5 is a GD&T manual and not a drafting manual... Which spec in that list shows me how to create a an angular dimension from it's axis of rotation to its second reference?

Any idea what I'm talking about here?

I'm not a vegetarian because I dislike meat... I'm a vegetarian because I HATE plants!!

 

[MikeHalloran]

It's probably time for your company to produce, adopt, or update, its own drafting standards manual to supplement or customize what the ASME document says.



Mike Halloran
Pembroke Pines, FL, USA

 

[CheckerHater]

People who rely on "knowledge of the 'old way' of drafting" are scared of standards because they render their "tribal knowledge" (and themselves) useless.
Ask your "checker" to produce actual document that he is following and listen to the sound of crickets.

 

[ewh]

Agreed CH. This is why I always get into trouble asking to see the documentation from the checkers. That said, there is a lot that is considered "old school" drafting that should be documented (in a DRM or other company standards). Makes for better drawings. You can have very poor drawings that don't violate the standards in any way, but are a bear to read, which is an opportunity for mis-interpretation and mistakes.

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[ctopher]

ASME Y14.5 is not for learning to do drafting, only GD&T.
Check out MIL-STD-100.

Chris
SolidWorks 13
ctopher's home
SolidWorks Legion

 

[ewh]

MIL-STD-100 has been cancelled, replaced by ASME Y14.100. For dimensioning, you get referred back to Y14.5.
I don't remember MIL-STD-100 being any more detailed as far as dimensioning, but I may be mistaken.

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[CheckerHater]

It was discussed several times on this forum, and mostly agreed that to “learn” drafting (including dimensioning) the most comprehensive sources are:
Genium Manual:

http://www.draftingzone.com/shoppingzone/

and
DRM:

http://www.amazon.com/Drawing-Requi...&sr=1-4&keywords=drafting+requirements+manual

Like it or not, both of them based on about the same stack of ASME standards. Both, unfortunately, got stuck in 2008.

 

[KENAT]

There is no way they are 'TOTALLY WRONG' when they say 14.5 is not a document about how to be a drafter. It lists certain requirements a drawing should meet with regard to dimensioning and tolerancing and more but it's not 'how to be a drafter'.

However, if they do have additional requirements for drafting beyond what section 1 of Y14.5 and the little bits related docs give then they should have some kind of specification to reference - even if it's a fairly informal list or a preferred drafting book or something.

When I was checking I tried to be careful not to arbitrarily impose my preferences, and certainly not to hold up drawings or make a lot of extra work to do so. When it came to things that would stop me approving a drawing I tried to stick to the relevant Y14 series docs and to the things our DRM clarifies plus of course the universal get out of making sure it's a generally clear and easy to understand drawing.

However, I would sometimes suggest what I considered good practices to be used on future drawings.

I think some of the limitations of 14.5 may be a result of it effectively being a consensus document, so some stuff not easily agreed on by those drafting & editing it probably tended to get left out rather than resolved.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[ctopher]

Thanks ewh,
I knew there was a replacement, but didn't go far enough to look it up.
I think the MIL std may be a free download somewhere to use as a start.

Chris
SolidWorks 13
ctopher's home
SolidWorks Legion

 

[ModulusCT]

Perfect answer CH... I will ask.

I'm not a vegetarian because I dislike meat... I'm a vegetarian because I HATE plants!!

 

[ModulusCT]

Well apparently, what OH said is absolutely true. Fully defining the part can be done a number of ways, and there may be a better way from time to time, but most of the time, here where I work, the checker just determines what is right and what is wrong... not based on some document she follows. Just based on what she learned during the many years she spent in the aviation industry. That's fine, but when I'm told that if I don't understand why she needs me to take a dimension from one spot as opposed to another, that I need to take a drafting class, I can't help but be a little irritated.

I think a good checker has to be a good teacher as well. Or at least, not a completely coarse and offensive person. The boss says that she's 'good' at what she does because she doesn't back down from what she believes... If that's the only virtue to being a checker, than I need to go back to school and get out of drafting. I've read 14.5 a number of times so that I feel I know how a good drawing is put together (along with 12+ years of experience)... If that's all thrown out the window based on some tribal knowledge than a lot of that work was wasted time apparently.

I'm not a vegetarian because I dislike meat... I'm a vegetarian because I HATE plants!!

 

[drawoh]

ModulusCT,

The title of my copy of ASME Y14.5-2009 is "Dimensioning and Tolerancing". This thing is a standard, and it explains what all those dimensioning and tolerancing symbols and notations mean. Given this standard, or any other standard for that matter, it means that everyone is speaking the same language.

GD&T is a subset of dimensioning and tolerancing.

--
JHG

 

[ewh]

To be well understood, it isn't just what "words" you use in a language that are important but also how you structure your "sentencences". Y14.5 is more of a dictionary than a style manual.

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[Belanger]

No, I think Y14.5 is pretty good at covering grammar and syntax too, not just the "words," as a dictionary does.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[ewh]

Thesaurus, maybe, but it lacks much in the way of creating a good drawing that a good DRM would cover, such as readability (optimized placement of dimensions).

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[powerhound]

Modulus,

Is there a specific drafting technique that is in question? If so, why don't you tell us what the conflict is and we can add our input in order to further complicate things...

John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II

 

[fcsuper]

I personally wouldn't take any drafting manual as gospel. After my interactions with the writers with Drafting Zone, I've discovered that their vetting process leaves a lot to be desired. In general, there are people with opinions on how things should be, but very little in the way of official statements from any agency. Bottom line, as long as you are communicating the requirements in an unambiguous manner, the drawing is suitable.

Matt Lorono, CSWP
Product Definition Specialist, DS SolidWorks Corp
Personal sites:
Lorono's SolidWorks Resources & SolidWorks Legion