×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Drawing Quality
4

Drawing Quality

Drawing Quality

(OP)
   This is a question for fabricators, inspectors and manufacturers.  thread1103-265767: Engineering Drawings and Tolerances is drifting off topic, so I am starting this thread.

   How good are the drawings you are being sent?  Do they make sense as per drafting standards?  Are you willing to promise to meet the dimensions and tolerances?   

               JHG

RE: Drawing Quality

From the other side of the fence, my money is on fewer quality drawings, especially since the introduction of CAD.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Drawing Quality

I am seeing less quality from vendors. In return, they request drawings from me to be less 'technical' and without GD&T.
I think companies have become lazier and have less employees that understand drawing standards and GD&T.
It's more of a 'cost cut' in management minds.

Chris
SolidWorks 09 SP4.1
ctopher's home
SolidWorks Legion

RE: Drawing Quality

drawoh,
Thank you for moving this. I would love to know peoples impressions, I suspect there are lots of drawings out there that people will laugh in your face if you applied too much GD&T. My wife is an engineer in a company who constructs water treatment systems, again not mass production stuff. they DO NOT use GD&T. All bent brackets, weldments and lots of tubing all fabricated outside they make nothing in house. They are booming now, just the right leading edge American industry.
Frank

RE: Drawing Quality

Vendors will only laugh when they don't understand GD&T (or automatically increase the cost %15).  Find a shop that understands it, and your cost could actually be lower.  It all depends on the industry I suppose.

CAD and CAM have contributed to the downward spiral, in both the frontend and backend of the process.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376: Eng-Tips.com Forum Policies to make the best use of these Forums?

RE: Drawing Quality

I think CAD, particularly 3D solid modeling, has improved the quality of drawings.  Maybe not dimensioning and tolerancing of the drawings.  It is almost impossible to make drawings from 3D solids that are physically impossible or with discrepancies between the views or assemblies that don't fit togeather.  I used to see that kind of stuff all the time with drafting boards or electronic etch-a-sketch CAD programs like AutoMAD.

RE: Drawing Quality

dgallup, you clearly have been blessed with more competant colleagues than I.

Just last week I was working in an assy file someone else had created and noticed some holes didn't line up.

3D CAD gives improved tools for finding these problems up front but no package I've ever used makes it impossible.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Drawing Quality

Modern CAD makes it very easy to create confusing and unnecessary drawing views.  Click-click, new view... click-click, new view.  I routinely see multi-sheet drawings with too many section and detail views that are not needed.  The worst was a 6-sheet drawing that I was able to reduce to 3 sheets.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376: Eng-Tips.com Forum Policies to make the best use of these Forums?

RE: Drawing Quality

I think that 3D CAD has averaged the quality out.  There are fewer drawings written on napkins, but there are fewer drawings made by skilled and knowledgeable staff.   

Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

&

RE: Drawing Quality

Guys,
Do you feel the tolerances on your fabrication drawings, (castings, weldments, formed parts) acurately reflect the tolerances achieved on your parts?
Frank

RE: Drawing Quality

  I seem to remember a history class where the teacher was telling us about the "Industry Revolution of the 1890's". He was saying that before that time a "furniture shop" could fabricate a piece of furniture at a rate of one piece a week. This furniture was a quality piece and the cost of this furniture was high. Then the industrial revolution hit, the same shop now generated 12 pieces of furniture a week, quality wasn't as good, but the price was reduced, and they didn't have to have the "craftsmen" they did before. So NOW more people could now afford useable "poorer quality" furniture!
   Fast forward to mid/late 1980's owner companies, on hard times, decide to drop whole design/drafting groups, & a majority of their senior engineering people. Now opting to replace the Sr. people with wet behind the ears engineering students fresh out of school with only afew Sr. types to ride heard over the Jr. people.
  Now AutoCAD pokes its head into things, with the new "Computer Revolution"! Now it's a whole new/different way to do drawings and lot of the Sr. people in design/drafting opted to retire early as appose to have to learn a new way of doing their job. SO now it's more important as to what computer program you know and developing your computer capabilities as apposed to developing your designer capabilities. This goes on this way for about 15 to 20 years. These days 3D is the "optimumal" way to document projects! Why? ...because with 3D you generate a "pictures" where it doesn't require anybody to be able to "read" a technical drawing. IF you're thinking this is not true, I'm here to tell you it's already happening, I've seem it! Projects are done 3D and "pictures" (with shading) are passed out to the welders. This is done because the cheaper welders don't read drawings too well and do better with pictures!
  This is the reason us "older guys" have heart ache with this whole thing. When I was taught mech. & piping drafting, it was hammered into you that your drawings WILL LOOK one way! That doesn't happen these days. What these computer programs put out would be unacceptable pre-1985 ...they DO NOT follow accepted drafting standards & convention! ...SO WHY are they acceptable now!??  ...Welcome to the Computer Revolution of the 1990's!
 

RE: Drawing Quality

"Do you feel the tolerances on your fabrication drawings, (castings, weldments, formed parts) acurately reflect the tolerances achieved on your parts?"

If I communicate with the machinists and explain the drawings each time, yes. Too many machinists these days that can't read drawings. I used to give it to them and walk away, then receive good parts.

Chris
SolidWorks 09 SP4.1
ctopher's home
SolidWorks Legion

RE: Drawing Quality

I can't argue that 3D models can make for a better product, but that is a different matter than the creation of a quality drawing.  Drawing standards are in place to aid in the interpretation of drawings, but these standards are seldom followed completely, be it a wrong weight/font line or a dimension line/extension line cross or GD&T; most drawings today are done by engineers who usually are only exposed to a CAD program but not the intricacies of an easily interpreted drawing.  So while the lines may be more consistently crisp and the lettering uniform using CAD, the actual ease of interpretation of the drawing has declined.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Drawing Quality

I don't think the furniture Industrial Age example is a one for one with the advent of the Information Age.  At the heart of the current standards are hundreds of lawsuits whose precedence aren't fading away.  With the adoption of 3d cad, the same level of detail and control is necessary on the model as it was on the drawing.  It comes down to the fact that furniture is just furniture.  Drawings or the 3d models are actual visual expression of contracts between to entities. A contract is a meeting of the minds between all signers.  PO law makes on the fly contracts.  If a model is sent to a vendor without proper and complete detail, there isn't a meeting of the minds. Once a dispute happens and goes to court, the customer is going to realize just how important detil is...just as it has already happened in the 1950s and 60s.   

Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

&

RE: Drawing Quality

Even the best CAD system we can ever imagine will not be better than the quality of a person that uses it. Of course it can make one's job quicker, drawing will be nicer to look at and easier to read, but if somebody does not know exactly what he is showing on the drawing, the content of such document will be very minor and benefits of using CAD systems will reduce significantly.

But coming back to OP's questions; I am working for automotive company that has many plants all over the world: US, Europe, India, Asia-Pacific. Different sites use different drawing and GD&T standards - US follow ASME Y14.5, Europe works according to ISO. We are of course using CAD system and producing hundreds of drawings per year, but I am very sad to say that I have not seen a single drawing that could be considered as fully done according to any of mentioned standards. Designers/drafters simply put remarks like 'Dimensioning and tolerancing according to ASME Y14.5M (or ISO 1101)' in general title block without thinking what are the implications of it. What is even worse, they do not use GD&T almost at all. And I am not talking about very simple parts like rectangular blocks or similar - geometry of our products is usually quite complicated. We have some internal rules saying that to avoid too complicated and unreadable drawings only functional dimensions should be presented, and I am OK with that, but engineers here are not even able to show these functional dimensions properly. Good example can be when symmetry of two features (let's say rectangular) is considered. Everybody will specify their widths, but nobody will care that geometrical relation between them is still missing. Most of guys will say: 'They are shown symmetrical on a drawing, so they are symmetrical, and that's all. If we add symmetry or position control on the drawing this will increase final costs of a product'.

Sometimes I wonder how lucky this company is that no serious problems caused by ambiguous dimensioning has happened so far. This might sound weird, but from my point of view (as a great supporter of using GD&T) I would like a situation to happen that somebody will come to us and say: 'Hey, there is no sufficient information on your drawing. Please fix it.' or 'You haven't specified it on the drawing, so we did as we thought, and you can not have any complaints to us that this doesn't work. If you want any modification you have to pay'. Maybe then our management would somehow realize that the company spends hard money on licences for sophisticated CAD systems to product worthless pieces of paper which instead of bringing huge profits can bring serious financial troubles.
 

RE: Drawing Quality

pmarc,
I think you and I must work for the same company/boss. It is good to hear I am not alone out here.
Frank

RE: Drawing Quality

Kenat,
I think that is about it. I was once told the difference between an engineer and scientist was something like a scientist is on a long search for the real truth an engineer needs just to get close enough, good enough, strong enough, fast enough to get the job done.
Basically, companies only want to get the work out. Walt says: "remember, companies are in buisness to make money".
It is people like us here who care enough and are interested in perfect drawings.
Frank

RE: Drawing Quality

11echo,
Shall I assumue you are refering to the times when real people made real prints, a little before my time? When I first started, I worked with a guy who shaded his drawings it was beautiful art, they would shoot the guy now. Most of my time, before CAD, their was mylar repos they were pretty ugly generally and not to scale usally either, I would not call that the golden age either. I was glad to leave it, frankly
Frank

RE: Drawing Quality

I totally agree with you fsincox, I don't know when this golden age was either; I must have somehow blinked and missed it. When I started out in the early seventies most design was done by hand and there was some great stuff drawn by highly skilled people but there was also some complete garbage around.

CAD is so much more than a few lines on a piece of paper, it has driven so many things forward and things are produced today that would simply be impossible without it.

Of course none of this alters the fact that the skill of the operator is still key, be that at a CAD station or on a drawing board.
 

RE: Drawing Quality

fsincox ... I have a personal story to tell you.  ...Back in 1976 after I had gotten out of the Army, I already had a Jr. College degree in drafting and I had gotten my first job as a piping draftsman. I had a very formal drafting education, and part of that were afew graphic design courses. One of my first job as a piping draftsman was to detail out a tank appurtenance drawing ...this tank wasn't more then an over sized trash can. But I was trying to do a good job, and in my "infinite wisdom", decided I could make this drawing better by adding shading under each nozzle! It looked GREAT! I wanted to take it home and hang up on the wall! But then I handed it to my boss he told me to set down and we'd go over it. ...So with a large red ink marker he proceeded to X out every bit of shading I had done! With red ink on the original it ruined the drawing. I didn't say anything; I was disappointed because in my mind I was trying to do "good". He could see I was alittle upset so he took the time to explain. He told me what I did looked great, but it wasn't per any drafting standard, and that if any body else tried to use this drawing after me, that he couldn't be sure if they had the talent to do as well as I did. He went on to explain that drawings needed to follow standards and accepted convention, but they needed to be as SIMPLE as possible so it could be assumed that the next draftsman down the road would have no problems using the same drawing to add or remove any modifications required. To be honest that "lesson" took afew years to sink in, but I never tried to shade anything again.
The lesson, that it seem almost everybody has lost, is drawings STILL need to be as simple as possible to insure that just about any body can use them down the line! Two axioms that just about says it all are as follows"
"NOTHING is make better by making it more complicated"!
The other lesson written between the lines here is...
"IF good work is not recognized, then poor work will follow!"

RE: Drawing Quality

11echo, you actually bring up a point that is perhaps even more relevant with CAD.  CAD, or at least the 3D packages I'm even vaguely familiar with, get more complex all the time.

Much of it is adding capabilities that some people will find very usefull.  However, often for most situations it just ends up with more than one way to achieve something, some of these ways are very complicated.

I've certainly opened files made by others that I needed to change and found it a real pain to do so, some because of bad practices, some because of complicated practices.

At our place the situation is complicated because we have a lot of 'part time' users, and a lot of interns who typically haven't used our CAD package before.

So, KISS rules to help future users, but it does sometimes limit how much advantage we can take of the CAD's capabilities, and yes, even I occasionally get carried away.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Drawing Quality

(OP)
11echo,

   Yes, for the sake of other users, you have to keep things simple.  On the other hand, you can dumb things down well below the minimum level to do actual design.  CAD is user friendly enough that dull, stupid people can perform most operations.  That does not mean that they can make design decisions, or understand assembly requirements well enough to communicate requirements on the documentation.  

   There is a minimum level of intelligence and knowledge for someone to be able to do drafting and design.  

   Whining and crying about how things used to be so much better, definitely can be tracked back as far as Socrates. Perhaps someone will dig up a Mesopotamian tell and find a cunieform tablet complaining that today's makers of machines are idiots.  The point of my post is that I am curious about what sort of average drawing the fabricators and inspector here are encountering.  The older guys can comment on what it looked like thirty or forty years ago.   

               JHG

RE: Drawing Quality

I'm sure that KENAT will be able to appreciate this winky smile

The rise of CAD coincided with the fall of the drawing checker.  After all, CAD makes things so easy to do, anyone can do it!  And that led to the downsizing or elimination of entire drafting departments, leaving drawing creation to the engineers.  This could have worked out well, if they had kept the drawing checker, but he was part of the drafting department and had to go.
Engineers need to see their drafting mistakes, omissions and poor practices in red.  Handing the drawing off for a peer check does little as far as good drawing practice is concerned (just re-inforcement of poor habits), and (in my experience) engineers often self-check because "it will get the parts out the door" quicker.  Proceedures in many places have become more lax, and drawings are often signed off and released without anyone skilled at drafting having any input.
Yes, there were poor board drawings back in the day, but there were also many more good drawings, depending on the company cuture.  It was a hell of a lot harder to correct your mistakes then than it is now on CAD, and those lessons tended to stick.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Drawing Quality

Don't get me started ewhwinky smile.

Anyway, there's no room for Checkers in the modern commercial world, what value does preventing errors in advance while educating folks have?  The engineers just need to be trained properly; we can rely on their professionalism to self-check and do it right.  Then rely on Scrap & Rework to speed up product development.  That's the way forward.

As to the OP, I do occasionally get actual drawings from vendors and generally they are pretty woeful, rarely enough info on them to do a tolerance check against for instance.  
 

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Drawing Quality

drawoh ...Did you "see" my last axiom I posted? ..."IF good work is not recognized, then poor work will follow!" ...If you don't know how things are done properly, how do you make the judgment call that things are better now? I'm guessing that because computers make things easier that they do a better job? I'm here to tell you that's not the case! A computer is nothing more then a fancy pencil and paper, even with a fancy 3D program. IF you don't clearly know what should come out of that computer to accomplish the job ...the same job that was done years ago on the board with pencil & paper, then it and the operator aren't doing their job! No matter how "pretty" it looks in 3D with shading! I believe that if you ask just about anybody that has done this on the board for a living (us "old guys"), they'd agree!?
 Now that you got me pegged as some "old Fart" that has computer phobia you are wrong again! I don't think anything has come along in this industry that has so much potential! However it has come with growing pains.
...People in positions without a "proper" education for that position.
...No national standards or conventions on how a computer makes the presentation.
...The number of different drafting programs that have divided up the work force.
...The fact that the major emphasis now is to up grade your computer skills as apposed to up grading your designer skills.
...AND the one that really causes me heart ache is as KENAT pointed out (and what I was hinting with my story about shading nozzles), computer guys like to go overboard on how they generate drawings! Because it's "fun" for them to intricately weave computer programs/commands/X-ref.s to generate a drawing ...so complicated that it takes the I.T. department or the original author to un-ravel it so some lesser qualified employee can use the file on another job! This is where the KISS principal needs to be implemented! ...AND where I point to on the first axiom I stated..." "NOTHING is make better by making it more complicated"!
 All this goes hand in hand for the computer age, as it has done for the "old days" on the board with pencil and paper  ...like it or not.
 
 

RE: Drawing Quality

Quote:

...No national standards or conventions on how a computer makes the presentation.
Well, there has been an attempt made at standardizing some CAD practices... ASME 14.41.
I'm not at all claiming that it is a perfect standard (neither is Y14.5 though), but it is a starting point.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Drawing Quality

Except...

It seems more telling the CAD programmers what to develop rather than so much telling CAD users what to do.  Also it doesn't really define modelling best practices so much as how to apply anotation in a model to replace a drawing and or how to have a model/drawing pair.

I agree it's a start point but there's a long way to go.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Drawing Quality

I wish the 3D CAD companies would concentrate on a way to section view radially patterned features (ribs, vanes bosses) that when sectioned would look like proper sectioning practice, any ideas??
I started around 1980, am left handed and a perfectionist. Drafting was a chore for me as I always rub my hand accross my printing and got bad hand/arm cramps from it. I was really excited about CAD now my drawings could look like everyone elses. I love the information I can get too.
Frank

RE: Drawing Quality

Quote (fsincox 23 Feb 10 19:04 ):

I wish the 3D CAD companies would concentrate on a way to section view radially patterned features (ribs, vanes bosses) that when sectioned would look like proper sectioning practice, any ideas??

Is what I was referring to.  Not sure what being left handed has to do with that, and who says I'm not a lefty anyway?

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Drawing Quality

Are you?
Frank

RE: Drawing Quality

Kenat,
When you cut a section on CAD it cuts through ribs, impeller vanes, bosses, etc like a saw. That is not the correct representation according to the old standard drafting manuals, mil or ASME standards rules on section projection. I have yet to find an easy way around this, yet it is so basic to drafting practice and I felt may     contributes to some of the "bad practice" mentioned here earier.
You don't have that?
Frank
 

RE: Drawing Quality

Frank, I think what you are referring to is called an "aligned section."  All the goodies about section views are labeled in ASME Y14.3.

I don't know about specific CAD systems, but I remember that section views can be cut from a "cutting plane line" that is not always straight across -- it can zig zag, or turn on an angle as in the aligned section that I mention.  However, when you see the section view, it makes it all appear as if it's in the same plane; you have no sense that the saw turned a corner.

Not sure if that's what you are referring to...

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

RE: Drawing Quality

Thanks, Guys
I guess I am not describing this very well.
Kenat,
Sorry, I am not at work now and I do not happen to have a copy of that standard here in my pdf collection.
Take a section through the center of a 5 spoke pulley wheel, I can cut the section so the spokes roll down into proper opposing places, but, the spokes then are also not supposed to be shown as cut through/sectioned.
Frank
  

RE: Drawing Quality

Note the section view on the left is how most cad systems would show the rib. The section view on the right is how it should be per drafting standards.

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net

RE: Drawing Quality

PeterStock,
Thanks, Yes, that is right except in the old days and per ASME Y14.3-2003, as Kenat has kindly provided above, the other rib should be rolled into place but not "sectioned".
They used to refer to it as true view vs. sectioned. To my OP they really need to work on sectioning or more likely the standards must be changed, I would hate to see the later though it may be more likely.
Frank

RE: Drawing Quality

I can only refer back to the '94 version, and thin sections should not show section lines.
It would be good if the latest made that a sugestion instead of a mandate.  While the CAD system I use can be cajoled to meet the '94 standard, it is much more involved than a simple section.  As for rotating into plane, I don't even try.  The cutting line would have to reflect exactly where the section is taken, no feature rotation.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Drawing Quality

Thanks!

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Drawing Quality

Amen, I knew that was the more likely outcome as I said above.
Frank

RE: Drawing Quality

Since CAD drawing quality has become terribly low.
I somewhat judge a company on their drawing (rightly or wrongly), the better looking drawings generally are the best done as far as accuracy and content.
I drew on the board for 10 years before going to CAD, and I still try my best to have the best drawings, and I get many complements from them.

RE: Drawing Quality

Anybody that's wants to go back to low contrast sepia's with smudges, erasures and coffee stains all over the place, views that were not redrawn when the dimensions changed and assembly drawings that were 5 component changes out of date is welcome to go back 30 years in my time machine.  You have to supply the 1.21 gigawatts.  The good old days were not that good, at least around here.

RE: Drawing Quality

As I posted, quality drawings were created "...depending on the company cuture."  Sepias were a shortcut method at best, and I still remember the scent of eradicating fluid.  Modified sepias seldom looked good, and the quality would decline with each modification.  On the otherhand, ink on mylar drawings usually held up well through many changes, but were a bit more delicate in execution.
The type of product manufactured and frequency of changes made a big difference, but good drawings were more prevalent then than now, at least in my experience.  YMMV

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Drawing Quality

I believe it would be hard to "judge" that quality ...or lack of it unless you've "been there"! The computer revolution has given us a lot of advantages, but with a number of growing pains too (as I pointed out)! The one we are discussing here now is one of the biggest. SO if everyone recognizes that there are "issues" with CAD generated drawings, how do you point a negative finger at the board generated drawings when it's held as a level of achievement ...coffee stains, smudges, & all!??

RE: Drawing Quality

I want to add one thing to the drawing quality discussion from my own experiance. When I was in the machine tool industry we adopted the standard around '87. We had outside trainers the whole bit. A lot of discussion here and other threads bemoans the demise of checkers. My experiace was a little different, the people most opposed to change were the entrenched checkers who prefered to keep things the "old way", they didn't like CAD and didn't like GD&T. This may also be a reason they were no longer viewed as value added.
Frank

RE: Drawing Quality

Kenat,
I realize now you have come from a later time. All the profile tolerances talked about here would have been laughed at when I first started. You have come to accept a whole new level of GD&T than when I started, it was mush more like some of the comments we get now, "what do we need to go to that for". I see the same thing in resistance to the 2009 standard, for example, it's statement that +/- is basically only good for features of size. Make no mistake some checkers were my mentors in many other ways, no doubt. Change is a given, resistance to change did them in.
Frank
 

RE: Drawing Quality

fsincox, not sure exactly how far back you go but most of the checkers I'm talking about are now around retirement age and had been working GD&T dating back possibly to pre 1982.  They came from defense/aerospace backgrounds though, as it seems do a lot (most?) of the people making most use of GD&T.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Drawing Quality

(OP)
KENAT,

   Everybody seems to have their own idea of who should do design checking, and how.  In the offices of Dominion Consolidated Widgets Incporated, the design checker may be a highly qualified professional that everybody respects and relies on, or he could be some goof that everybody wanted kept away from the drafting board or CAD station.  

   This sort of thing depens massively on who you are working for.  

               JHG

RE: Drawing Quality

Kenat,
I really do not believe the majority of old checkers knew GD&T. I would like to believe we would be much farther ahead if they had. I once refered to the people you are refering to as the best and the brightest of their time, someone took issue with that statement when I made it before. I would still maintain that the people you know were the best and brightest of their time. Unless you just mean they knew the words like: parallelism, perpendicularity, concentricity and symmetry. those checkers I knew, too. Parallelism was like a snake.
Frank

RE: Drawing Quality

No they were good, one of them occasionally gets on here and was the best of the bunch.  For the most part they had a very deep understanding of the GD&T - much more so than me - while still having a reasonable grasp of the more practical side of things.  They didn't get caught up in some of the minutia like some of the more 'expert' members here do, but it wasn't generally because they didn't understand it.

While a sample of 3 folks isn't that large, they were very good.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Drawing Quality

  Yes, it does depend on the company culture.  Most of the checkers I have worked with (from the early 80's on) had a strong working knowledge of GD&T; if you disagreed with their interpretation of the standards but could not back it up, their opinion stood.  If you could back up your position with the relevant standards, they would aquiesce.  The majority of the time, they were correct.  The time spent in attempting to prove them wrong was valuable in the lessons learned.
  I do not and cannot claim that a majority of checkers back then knew the standards very well, but I can claim that most of the ones I worked with did, and what they did not know they were willing to learn as it was presented to them.
Again, YMMV.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Drawing Quality

Realise, I was only stating my perspective, too. I am asking how others perceive things. That is really why I am here, to continue to learn and change. How do you explain the whole, "we need certification," if you are correct and there were so many good people out there, It just doesn't pass my fishy smell test.
Frank
 

RE: Drawing Quality

Sorry, GD&T certification. I have always realized some people may work in more progressive environment. I am maintaining that all the discussion here and in the Yahoo group about the poor state of GD&T application, coupled with the fact there was a call for "certification" of "experts" leads one to suspect you were fortunate. On the other hand it could have been sales propaganda, I suppose, by those selling the standard. But, I do not perceive it that way, you?
Kenat,
Are you English originally; You mentioned you worked there when we first talked, but now, after reading back it appears different.
Frank

RE: Drawing Quality

English originally, now a yankee doodle dandy, or maybe not as I live in CA but a US citizen anyway.

Regarding certification, I looked into this when I got landed the checking role, I even got the study guide.

However, having looked at it a little (not enough) and talked to some others, I have the perception that they perhaps set the bar too high for the initial level of certification.  The amount of time & effort I'd have to spend to get it didn't seem commensurate with the benefits.  I haven't seen many job adds asking for GD&T certification, just for experience with ASME Y14.5 etc.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Drawing Quality

Thanks Ken
The checkers I worked with then, did not know any standards but "company standards". They had no interest in national standards any more than if they were ISO standards. Now I work in areospace and I see a nominal interest by management in at least looking like we adhere to standards because the apperance of it is good for buisness so I do see the difference.
Frank  

RE: Drawing Quality

Ken,
I am reading your thread 1103-192933 on GD&T parts costing more. Powerhound's comments about bad GD&T stand out in particular as he references his perspective. That and many other threads here indicate to me from the outside world that you were very lucky to have a good friend/mentor. I did too, he was a checker also, Art.
Frank
 

RE: Drawing Quality

I can speak for two US manufacturing companies, and say without any reservation whatsoever that 99% of the people I work with, even the ones that produce drawings, don't know how much of the drawing standard works.  I even had a senior engineer try and tell me that basic dimensions aren't required for true position tolerances!  Even though our prints go through three people (drafter, design engineer, manufacturing engineer) who are supposed to check them for problems before they reach us, we find issues constantly.  The more I learn about the standard, the more I believe that the number of prints I've seen that comply to it completely could be counted on my fingers and toes without taking off my shoes.  As for visual quality, it varies widely.  Sometimes we can barely read prints, particulary if they're for an ECO, and sometimes they're high resolution and extremely easy to read.  I believe several posters hit things on the head: People don't know the standard, don't want to know the standard, and the companies don't care - or at least, not until they get some bad parts because the drawings were garbage, at which point nothing happens except they mark up the print on the floor and remake or rework the bad parts.  CAD has helped for high-complexity parts, I think, but where I work there are several CAD packages being used in parallel, many older engineers who don't want to learn 3D drafting (let alone GD&T and the drawing standard), and lots of young engineers fresh out of Virginia Tech who learned CAD modelling upside-down and backwards at school but nothing about actually producing drawings (Yes, I've asked them and they stated unashamedly that they learned nothing about dimensioning and tolerancing).

RE: Drawing Quality

I mentioned here before a story: I was in an argument with our lead of quality, the nominal head of our GD&T effort, he claimed that you allways know how to layout parts in inspection because; "A is primary, B is sec....., etc". I asked him why do they bother to reference datums in the DRF then if it is always the same and you are going to ignore that part of the frame. I think he quickly got the point.
Frank

RE: Drawing Quality

I took a drafting course in college before there was any CAD software.  They did not teach a word about dimensioning and tolerancing then either.  Technical schools may have taught it but not my 4 year engineering school.  I absolutely hated board drawing and for the first decade of my career we had draftsmen working on boards.  I did take GD&T courses and studied drafting standards as part of my work experience.  I would not be doing what I do today if parametric solid modeling CAD had not come along and displaced all those asleep at the board drafters.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources