Degradation of Drawing Standards 13

[chancey]

Ok I am not old old school because I didn’t start on the board but has anyone else noticed the degradation of drawing standards? I think this really boils down to the use of CAD. Now that most packages have become easier to use (unlike the early versions of Pro E & MDT) I think more people are creating drawings. Things I see a lot of are missing hidden lines (I understand clarity reasons), lack of centerlines, dimensioning with disregard to intent (like not coming from datums), lack of tolerance consideration (like 3place decimals throughout), dimensioning to hidden lines, poor overall dimensioning & view layout, over crowding, etc. And god forbid they try to use GD & T.

I must just be getting older and grumpier…

 

[MadMango]

Let's not turn this into a 2D/3D drawing/no drawing thread, and keep it a "bash poor drafting methodology" thread.

 

[macgyver247]

A recent favorite of mine is dip your brush in the GD&T ink well and proceed to spatter it all over the drawing. If you put enough GD&T on a drawing you are sure to get a part that should fit your application.
I think The Tick summed it up above, Same standard, Poor compliance.

 

[vc66]

There aren't enough drafting experts anymore. When I got out of college, I couldn't make a drawing for my life. In my first company for about 2 years, I had an old draftsman beat good drafting practice into my head. That's the only way to learn.

I think a lot of the REAL drafting information is not in any standards, and it's just based on tribal knowledge. There aren't enough good drafters around to teach the young bucks.

V

 

[ewh]

That's because good drafters are seldom hired for their expertise anymore. Management just doesn't see the benefit, when they could hire another designer instead.

"The ambassador and the general were briefing me on the - the vast majority of Iraqis want to live in a peaceful, free world. And we will find these people and we will bring them to justice." - [small]George Bush, Washington DC, 27 October, 2003[/small]

 

[dgallup]

I disagree with quite a few posters. I still have to dig out quite a few 20+ year old mylar drawings from Ford, Chrysler, etc. and they are awful compared to what we produce on the computer today. Fuzzy, indistinct lines, huge sheets (oversize E) for small, simple parts. I swear those guys must have been paid by the square foot.

I think one of the key things lacking in most midrange CAD systems is the ability to enforce standardization. A lot of these systems (SW & Acad are particularly guilty) allow each user unlimited freedom to mess things up. I setup our Pro/E system with standardization in mind & every drawing has identical line weights, lettering, etc. etc. That doesn't mean a incompetent user can not make a bad drawing but we don't keep those people on too long.

I agree most new engineers don't have a good drawing/drafting background but I didn't either when I graduated 30 years ago.

 

[ewh]

No one is claiming that all board drawings were better than todays CAD drawings. But in my experience, the board drawings (done by a drafting department) at every company that I have ever worked at are much superior to the CAD drawings that come out of most of todays engineering departments. Your mileage may vary.

"The ambassador and the general were briefing me on the - the vast majority of Iraqis want to live in a peaceful, free world. And we will find these people and we will bring them to justice." - [small]George Bush, Washington DC, 27 October, 2003[/small]

 

[TheTick]

The decline of drafting means the decline of a common design language.

Yes, it is possible to fully document in 3D. What is not really happening (yet) is the evolution of a common, widely used 3D design language.

Every so often I am reminded of the limitations of 3D vs. 2D documentation (yes, I typed those in the right order). Engineering professionals take too much for granted w.r.t. non-techies ability to fully read and comprehend a design in 3D. 2D really does work better to get the message across for many folks.

 

[KENAT]

dgallup, sure line weights etc. used to be an issue. Now they shouldn't be for the most part. I've seen a few poor old drawings but on average, trying to allow for the evolution of drawing standards over the last few decades, the ones I saw were probably better.

My biggest concern on drawings (and the limited hibrid 3D MBD we do) is that people aren't properly defining the part especially with respect to tolerancing. This is then compounded by poor drawing layout etc.

The drawing (or MBD package) should be unambiguous, for the most part they aren't, or even if they are unambiguous to them selves they don't support correct fit etc. at the next level.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:

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

 

[ctopher]

Whether it's CAD or board drafting, done by drafters/designers/or engineers, standards by ESME/ASTM/DOD/MIL/etc are just not followed by most anymore.
I see CAD apps setup all the time with some standards, but are usually setup by IT/CAD mngrs/eng/etc. Usually by people that do not know the standards.

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[fcsuper]

There are definately "not enough drafting experts". The problem is that many engineers who've didn't even take a drafting curiculum in school think they are drafting experts simply because the software does a good portion of the *drawing* work for them. Drawing something quickly doesn't make someone a knowably *drafter*.

I think that drafting is the tailend of a long tradition. Back in the middleages, they had drafters, but their job then was mostly to reproduce other works accurately. Over time, this task expanded into having the responsibility to create the works from under-detailed notes. Sometime in the 19th Century, the field started becoming more formalized. The need is still there, but it's going to take some big lawsuit to help the general industry to re-realize it.

Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group

 

[KENAT]

I found out today that the Engineering Director thinks I spend all my time telling people to move notes a few fractions of an inch.

This despite him having had my boss & I prepare a report on the types and approximation of frequency, of errors that I found late last year.

I don't remember listing 'notes out a fraction of an inch' as one of them.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:

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

 

[ctopher]

Tell him the tolerance is +/- 1 inch, you're within spec.

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[DesignerGuy16]

I was lucky enough to learn on the board in high school. My teacher was very good about railing in the standards.

Problem with engineers doing their own drawings is most "engineers" didn't take years of CAD training prior to making drawings.

I was on the academic advisory board for the CAD program at the college I graduated from (and I only took descriptive geometry for fun). The industry members of the board from Chrysler, Delphi, etc all had the same complaint that there were a ton of people who could work in 3D, but couldn't read or create a blueprint. My reation to that is how can you create the model if you can't create the documentation to back it up?!? There's something fundamentaly wrong with that.

I'd love to see drafters still start and learn on the board, and to get some training in quality control to really learn how parts are measured. That way they can link the dimensions with the measurement, what's critical, etc.

James Spisich
Design Engineer, CSWP

 

[Brandy7]

BRING BACK THE CHECKING FUNCTION

 

[ewh]

No, many companies do give lip service to the checking function, but it is usually peer review. What is needed is to BRING BACK THE CHECKERS!

"The ambassador and the general were briefing me on the - the vast majority of Iraqis want to live in a peaceful, free world. And we will find these people and we will bring them to justice." - [small]George Bush, Washington DC, 27 October, 2003[/small]

 

[dingy2]

Bring back the Checkers??? That is a bit like bring back Inspectors on the factory floor and our quality problems are corrected. Checkers or Inspectors don't fix the problem.

Training is the problem. After the training, it is the application of the training.

How about placing hidden lines where they are applicable? Are your object lines are a bit heavier? How about 3rd angle projection - are the projections correct? Does the Designer even use chain lines or chain line boundaries at all? I am not even getting into GD&T where, frankly, it is pretty awful out there and a lot of Designers covering their butts by sticking it in notes without any thought of the feature's function or relationship to other features.

Just some thoughts from a user of drawings.


Dave D.

http://www.qmsi.ca

 

[ctopher]

I agree, training is the issue. Just like our schools, training is always the first to get cut. Then motivation goes away.

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[ewh]

Oh, I agree that training is the real answer, but complete checks need to be done until new drawings are meeting expectations (the staff is trained). Every new hire that is to produce drawings has to have his work completely checked to verify quality. Then you can turn them loose. Cursory and full spot checking is still necessary, by someone who understands what they should be checking (not a peer review). Just getting a "certificate" that claims you know drafting is no guarantee that bad habits won't surface.
It's the same on the floor. You don't inspect every part made, but you do a statistical analysis where samples of parts are checked. If they don't meet expectations, the manufacturing procedure is revisited. But you have to look for the problems before they go out the door (or in the case of drwings, before they hit the floor).
The last thing I want to do is have to fully check every drawing new hires or the contract firm we are using is producing, but until one comes across that meets expectations, ALL will have to be checked.

"The ambassador and the general were briefing me on the - the vast majority of Iraqis want to live in a peaceful, free world. And we will find these people and we will bring them to justice." - [small]George Bush, Washington DC, 27 October, 2003[/small]

 

[KENAT]

I'll have to disagree with several and say that ideally all drawings, with the possible exception of some in house tooling and the like, should be properly checked by a suitably qualified person.

I'm primarily a checker (at least for now), but still make my own drawings sometimes. The last one I did I'd gone over several times on the screen and printed out a copy and went over it till it looked good. I passed it to a contract checker we have to take a look and he almost immediately found a mistake, just the one but a mistake that would have caused a problem had it gone out. People make mistakes.

Training is definitely a big part of the solution (or lack there of the problem) but people also have to be forced encouraged to apply that training. A slightly trite saying, but arguably fairly true in many cases, says "People do not do what you expect, people do what you inspect". Everywhere I've been people have been pressed on schedule, it's easy to cut corners on drafting in that situation.

Also, done correctly, having prints checked is itself training in a very practical, hands on, real world, way. It's pretty much how I learnt to draw, I'd done a little at uni & high school but having my prints bled on is what got me up to par, not some highly theoretical, very brief, training class.

(We manage to screw this up though, while permanent engineers create many of the drawings I check, the redline incorporation (and sometimes all the detail drafting) is given to interns to do. So the engineers don't really get the feedback [they are usually asked to approve the redlines but I'm not sure how much attention they pay] and don't really learn.)

The analogy to inspection as dingy puts it isn't quite correct in my mind. Places I've worked do have full inspection of first articles most of the time, moving to sampling etc after that. Well the drawing is used to get the data to create & inspect the first article, so it's arguably critical that it's verified for accuracy in its own right. So I'm still convinced that checking is worth the effort even though I'd be lying if I said I loved doing it myself.

Still this is getting slightly off topic and has been discussed before. Theres a bunch here who still think checking's relevant, there's others that think it went out with the ark, in my time on this site I'm not sure anyone's ever changed their mind.

I can't say I look forward to seeing what happens round here if the Engineering Director really has persuaded the new manufacturing VP to accept the same crap level of drawings we used to have before I started.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:

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

 

[MadMango]

A real eye-opener for some management types is to collect the cost of changes through your ECO/DCN process to correct poor drawings. Once you give them "hard proof" over a 6mos or year period, the resistance goes down a bit (until the next pressing project).

I vote for cattle prods attached to red pens.