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ANSI Y14.5 dim standard

My question is about the standard, not necessarily Pro/E. I'm actually helping to define a very simple CAD like product for mechanical designers and need a refresher about a dimensioning subject.

When dimensioning in 2D and I want the dim text aligned with the dim line (thus not always horizontal); I am assuming that a perfectly vertical dimesion would always read from the right side of the page. Example, if dimsion text is to the left of an object it would be above the line reading up the page; if dimension text is to the right of an object it is also abovce the line reading up the page. This is how I learned it in the Architectural trade. Rather than having the text always on the side away from the item being dimensioned.

Question 1a & 1b: is that clear and correct?

Question 2: Are there any ANSI rules or common rules about what to do with aligned text on say a 22.5 degree angle?

I'm just trying to figure out when to have the text flip above line line rather than starting to read like it's upside down.

If this is hard to understand, I'll state it differently here. What if I had a 2D view of a gear with 360 teeth and I placed dimensions showing the the pitch of every tooth, radially around the gear. How would the text be arranged. I assume the text exactly on the x coord at top and bottom would read from the bottom of the page. I also assume the text exactly on the y coord would read from the right. Or would the one at the left read from the right and the one at the right read from the left? And how can you describe how the various text entities at the various compass points should be aligned.

Sorry for the labored question, just looking to see if this use of the web can answer my Q, as an hour of searching hasn't done it yet.

Reply to
Bill Wallace
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Bill, I think your questions are not really answered by Y14.5, if I remember correctly, but perhaps by another ANSI/ASME standard. I don't have copies of all I used to own, but I can tell you basically what is usual and acceptable in the mechanical design world.

Typically dimensions are to be readable from normal orientation (i.e., "from the bottom") or from the right-hand side. If dimensions are at an angle, it's acceptable to have them oriented so they read anywhere between bottom side and right side, but not outside that 90 degree arc. However, most machine shops prefer that dimensions read from one orientation only -- that is, from the bottom. The reason is that they typically lay the drawings out on a work table and don't want to have to pick them up with greasy hands to turn them so they can see clearly, and they may not be able to walk around the side of the work space where they have the drawing laid out.

And in mechanical drawing -- unlike architectural drawing -- the dimensions don't go above the dimension line. They either go directly between the arrows or they come out from a leader to one side of the gap between extension lines (outside the arrows).

Hope that helps,

Mark 'Sporky' Stapleton Watermark Design, LLC

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Reply to
Sporkman

I think you've posed a question for the ISO standard. They generally dimension above the line and straight out from the dimension line. ANSI, on the other hand, most often keeps the dimension horizontal and puts an elbow on the dimension line, when placing the dimension outside the witness lines. This is generally taken care of in Pro/e by telling it that your dimensioning standard is ANSI and that you are centering dimensions between the dimension lines (i.e., not above or below).

David Janes

P.S. You will not find this on the internet because ANSI, a quasi-governmental body, charges exhorbitant rates to industry, $100 per book, for their standards or approx. $1000 for the set of the ANSI Y14.x standard.

Reply to
David Janes

"> P.S. You will not find this on the internet because ANSI, a quasi-governmental

Y14.2 - $70 for a 16 page book. I have it, and it was a complete waste of money.

Reply to
John Wade

"> Hey, John, think of it like this: how much more 'taken' would you have felt if

Good point well made. I am perpetualy astonished at the cost of standards which were quite clearly written by people who cannot get fired for doing a crap job. Maybe it's just the eternal optimist in me, always expecting the next one to have some useful content...

Reply to
John Wade

My well meaning but disinclined to listen to anyone stupid enough to work for them (there's a kind of perverse logic to that) employers occaisionally reel in some knuckle trailing simian to deliver training on something I've known for years. I generally treat these clowns with the contempt they seemingly deserve, but if they're blagging that sort of cash they must be smarter than their slack jawed countenances indicate...

- I actually like Y14,5 - It's pretty clear and unambiguous.

14.2 has a great section explaining the fundamental requirement for a drawing is that it's legible. You'd be surprised how many people need that pointing out! I'm trying to get our standards guy to volunteer for the ANSI committee to get him out of my way.
Reply to
John Wade

: > : Good point well made. I am perpetualy astonished at the cost of : standards : > : which were quite clearly written by people who cannot get fired for : doing a : > : crap job. Maybe it's just the eternal optimist in me, always expecting : the : > : next one to have some useful content... : > : : > Maybe it is the cost. I've been online to every public library catalogue : in San : > Diego County (city and county library systems, three universities with : graduate : > engineering programs and half a dozen two year schools with CADDDDD : programs). : > ANSI Y14.5M-1994 is not known or available here in any library. But there : are a : > few 'institutes' and trainers around who hold 5-day, $5000/person courses : on GD&T, : > Tolerance Stackup Analysis, etc., being the expert interpreters of ANSI : > Y14.5M-1994. Some of them sit on ANSI/ISO technical committees. Could that : have : > something to do with why the standards are so expensive, so obscure and so : > unavailable? :

: - I actually like Y14,5 - It's pretty clear and unambiguous. : It's not the standard, per se, that I object to. It's the fact that it is the high school physics teachers answer book. You get all the conclusions, all the answers to the mysteries, without the problems they answer or the procedure for working it out. So, in the end, it winds up bein just about useless and only fodder for the courses that do explain what problems you can solve with a particular standard and the procedure for doing so. The standards are written like Congress writes laws: for lawyers to debate in court. Can you produce stuff by standards whose application is meant only for debate, whose applications are not as precisely defined as the standard itself!?! No, I think standards like this are meant only for the interpreters of standards, to give them jobs, authority and a very nice living.

: 14.2 has a great section explaining the fundamental requirement for a : drawing is that it's legible. You'd be surprised how many people need that : pointing out! I'm trying to get our standards guy to volunteer for the ANSI : committee to get him out of my way.

Unfortunately, in my part of the world, the most popularly cited, possibly used, standard of the series, 14.5, is not available in its latest release (M-1994). So, I'm quite certain that the engineering community here has never even heard of

14.2, and, shame that it is, they don't much feel the loss. So much for standards in the US engineering world.

David Janes

Reply to
David Janes

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