Avoiding Redundacy 1

[MrGearhead]

Can anyone point me to a chapter and verse in any dwg standard (prefereably ASME 14.5) that provides guidance on avoiding redundany in standard dwg practice? i.e. FNs on an assy dwg... If used more than once, the redundancy is noted as a "reference" and this is in the case that it IS needed... What if something is not needed? Such as a view, etc... Is there some sort of general wording that conveys "avoid redundacy to increase clarity and chances for mistakes"?

 

[gabimo]

Page 4
NOTE: A reference dimension is a repeat of a dimension or is
derived from other values shown on the drawing or on related
drawings. It is considered auxiliary information and does not govern
production or inspection operations. See Figs. 1-19 and 1-20.
Where a basic dimension is repeated on a drawing, it need not be
identified as reference. For information on how to indicate a reference
dimension, see para 1.7.6.


Page 8

(c) Each necessary dimension of an end product shall
be shown. No more dimensions than those necessary for
complete definition shall be given. The use of reference
dimensions on a drawing should be minimized.

 

[Tunalover]

Not every sound practice is invoked by standards. It's just good drafting practice to avoid redundancies. Along the same lines, I don't think you'll find a standard that says to never dimension to a hidden line. That is just good drafting practice. Maybe a drafting room manual will spell it out but I'm certain it's not covered in any ASME standards.


Tunalover

 

[ewh]

Y14.3-2012 ¶7.2
"The minimum number of views necessary to describe the part is shown."

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

 

[Tunalover]

ewh, must be nice to have all the ASME specs. They're so expensive!

Tunalover

 

[ewh]

One of the perks of working for a huge company. The trouble is getting the right people to actual read them!

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

 

[KENAT]

The reference issue on find number balloons is not in the ASME standards as far as I know, and in my opinion isn't correct anyway but I can't give chapter & verse why.

Tuna - I'm pretty sure not dimensioning to hidden line is in one of the stds but off the top of my head I can't remember which.

Posting guidelines faq731-376

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

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

 

[Tunalover]

Kenat- A lot of people get caught in the trap of proving every drafting practice by pointing to a passage in a standard. There are things that are taught on-the-job and in drafting courses that I call "good practices" that aren't always delineated in a DRM or standard. On the other hand, it IS nice to know that a practice you hold true is documented somewhere. As an engineer most of my drafting knowledge was picked up on-the-job but you'd be amazed at the things that so-called educated designers and draftsmen do that runs counter to good drafting practice (like dimensioning to a hidden line). A lot of people get used to doing it a wrong way and continue to do so saying "that's the way we've always done it." I'm sure I'm preaching to the choir.



Tunalover

 

[TWJR]

Tuna - I'm pretty sure not dimensioning to hidden line is in one of the stds but off the top of my head I can't remember which.

It's in Y14.5M-1994, section 1.4(g)

(g) Dimensions should be arranged to provide required
information for optimum readability. Dimensions
should be shown in true profile views and [highlight #FCE94F]refer
to visible outlines[/highlight].