Need some help - New job & I'm not producing drawings that are 'good enough'. 4

[ModulusCT]

Can someone please point me in the direction of some resource where I can brush up on my drafting practices? I have an ASME in mechanical engineering tech with a focus on design, and have spend the past 13 years doing design/drafting work for various companies. Before I took my most recent job, I did myself the disservice of working for a company that had very lax drafting requirements, for EIGHT years, and so now, in a new industry that is very much focused on the good drafting practices I find myself at a disadvantage.

Many of my mistakes have been silly -- actually stupid -- mistakes, like not putting 2X in front of a dimension that applies twice on the same view, or forgetting to put a centerline on a cylindrical part... things like that. But also, our checker, who has 35 years of drafting/checking experience in the aerospace industry has a very unique (to me at least) way of considering a drawing good. Many or most dimensions for features are taken from holes which are called out as datums. So, first, and angular dimension is usually necessary to create the first leg of the dimension that is parallel to the second leg of the angle dimension (which is parallel to the surface or line to be dimensioned. Then the distance dimension is taken from there. Completely new to me. In the past, all of my drawings have used a baseline sort of dimensioning scheme where things where dimensioned from the bottom left. It mainly has to do with the fact that the industry I'm in now makes a lot of parts with curves and angles and before I was working with parts that were mostly square.

Anyway, I've been given 30 days to 'significantly' improve the quality of my drawings... Else, I'm out of here. I'm pretty sure that I can eliminate a lot of my problems simply by being a better checker of my own work (something I've been lax about for some reason)... and yet, there seems to be things that I don't know about drafting that the checker believes should be basic things I should have learned long ago. My theory is that drafting practices are mostly tribal knowledge. There are many ways to correctly dimension a part. My challenge however, is to do it the correct way as this company sees it.

My problem is compounded a little by the fact that I'm using a new software package (solidworks)... I'm picking it up quickly, but still, there it is.

So I'm wondering... Is there a drafting for dummies out there somewhere in cyberspace I can study? Are there some checking guidelines I can follow to ensure that my drawings don't come back from the check even once with red on them?

Eliminating my silly errors are going to help a lot... I've been making too many of them. Mainly because of a poor attitude. Something only I can change... That's on me. And I've read recently that a good attitude, or rather, a bad one, can manifest itself in a drafters output in profound ways. I'm going to work on that. But proper drafting practices... Beyond looking at other drawings done at this place I work, I'm unsure where to go for advice. I've always used ASME Y14.5 as my go to guide for good drafting practices, but apparently, that's not really a guide for good drafting. That's a GD&T guide first and foremost. I know that standard well. Unfortunately, ASME 14.100 is not a wealth of information, but rather, just a general guideline. Nothing that will help me now.

Any questions for me, please ask... Any help is greatly appreciated. I do not under any circumstances want to be unemployed at the end of December. Please, if you have any guidance whatsoever, don't hesitate to lay it on me. I'm all ears/eyes.

Mod

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

 

[3DDave]

Hi ewh!

I was concentrating on the creation of drawings, not the entire design process. Still not something to leave to the checkers - materials, material cost, manufacturing capability, manufacturing cost, turn-around time, production rate, scrap rate, inspection capability, capital equipment, depreciation, development, testing, training, and all the other items that go into finding out the correct limitations for the dimensional and other drawing requirements.

As to the value of doing the things I mentioned, a good checker will also verify that drawings are consistent, so that production doesn't get multiple versions of the same requirement. Nothing like a bunch of ways of wording plating or painting notes and trying to figure out if the results should be different because the wording is different. And if the checker covers multiple programs, so much the better.

Doing this can be incredibly valuable - how nice it is to write one wording change to a note that covers hundreds of drawings instead of writing hundreds of changes because the notes were inconsistent. Turn a pack of engineers loose and you can often kiss consistency goodbye.

Did I mention that engineers sometimes skip part of their job? Like tolerance analysis or making sure the .250-20 screws go into the .164-32... I mean .250-20 nuts? Under those circumstances a good checker is especially valuable. Maybe the trouble is people who are not engineers get placed in engineering jobs, so they don't know what they should do.

Where I worked for a long time the drafting group and the check group gradually got whittled away. The main problem for the checkers was that their immediate costs are so obvious, but the long-term savings are not. The funniest thing was the program management demands that the engineers should all just get together and agree on how to produce a consistent drawing product, without including any task or budget (or themselves) in the program plan for this meeting of the minds. They'd complain the customer was unhappy about inconsistencies in the drawing package and blame the engineers.

I miss the good checkers and despised the poor ones, especially the 'peer review' ones who didn't check as much as back-seat redesign (not based on function or analysis.) The checkers were finally overcome by too large a work backlog - can't get anything through check? Eliminate the checkers. Of course having fewer checkers had led to worse drawing practices (less feedback), which meant it took longer to mark up the drawings, which led to longer delays in check, delaying programs and so on.

tl;dr I stand by it - the last thing a checker should be concerned with is how a part is dimensioned - that's what the engineers and QA are paid for. If the checker is spending (much) time on dimensioning, someone is not doing what they should be doing.

 

[ewh]

At risk of going further into the weeds...

If the checker is spending (much) time on dimensioning, someone is not doing what they should be doing

I agree, but I don't think it's the checker!

Verifying proper dimensioning is far from the entire design process (materials, material cost, manufacturing capability, manufacturing cost, turn-around time, production rate, scrap rate, inspection capability, capital equipment, depreciation, development, testing, training...). The checkers role includes ensuring that the drawing is complete and concise, without ambiguity. Tolerance accumulation is not often considered when an engineer is trying to get drawings out quickly after a design has been deemed acceptable, and it is often overlooked. Too often, drafters will give an engineer exactly what he asks for, right or wrong. A good checker will catch this, as well as raise questions regarding incompatible materials, less expensive manufacturing methods, inspection capability, etc. It is not his responsibility to make these decisions, but to raise the questions to the engineer to cover any oversights that may have occurred (no one is perfect). The more experienced the checker, the fewer, but more pertinent the questions will be.

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

 

[desertfox]

Have a look at this link re drawing checking

http://www.roymech.co.uk/Useful_Tables/Drawing/Checking.html

 

[fcsuper]

The value of a checker is their ability to determine/understand design intent and make sure the drawing fully defines the product correctly with design intent and manufacturability in mind. Spelling and consistency are actually secondary to this.

My experience is that peer review is only useful if you have peers that actually know how to define product via a drawing (pretty rare among engineers; and only a bit more common among a group of drafters). Involving peers can be a double-edged sword. I've had some really bad experiences where a peer thinks they know GD&T, but are actually fairly ignorant on the subject. Disagreements with peers over detailing can be bad for the engineering group, because trying to educate someone on-the-fly tends to be taken as personal challenge/attack, rather than an opportunity for them to learn.

Checkers are generally a good neutral body. This doesn't mean dedicated checkers solve all your problems. They still need to be willing to grew and learn too, but also, they can be used as a teach tool within any group.


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

 

[Enginerd9]

You said it here: "But also, our checker, who has 35 years of drafting/checking experience in the aerospace industry has a very unique (to me at least) way of considering a drawing good."

What I think you're running into is someone who's had 35 years to become set in their ways, with "blinders" on so they don't see how the drafting world has evolved in that time frame. For example, "Typ." was standard in ASME Y14.5 1994, but in 200-2004 they decided to encourage the use of "2X" or (2) for example to remove ambiguity. The Aerospace industry has to be very particular about seemingly tedious things for good reason, so maybe he's having a hard time getting out of those habits in an industry where those tedious things aren't as critical for function.

I've had the pleasure of working for a few different companies so far in my career, and what I've noticed is that each company has its own "standards," that is, each one interprets the standard their own way. And of course you'll find that with people too.

My recommendation is: grab a personal copy of whatever relevant drafting / dimensioning standard you need for your industry. Read it, carry it with you, etc. And, when you submit your work, have it handy and be ready to defend your work. Don't let someone else cause doubt in your self-confidence. You rock, and you've got your own professional history to back you up.

 

[ewh]

For example, "Typ." was standard in ASME Y14.5 1994, but in 200-2004 they decided to encourage the use of "2X" or (2) for example to remove ambiguity.

Where did you get this information? "X" has been used to denote qty at least since the 1994 version (as well as 1982 I think, but I don't have a copy of that one with me), and never has it been directly suggested in the standard to use parenthesis around a quantity, which would render it a reference value and add ambiguity.
It seems as if you have been working to an interpretation of the official standard, and not to the standard itself. There is nothing wrong with following an official company standard; just don't expect all of the same rules to be followed at a different company.

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

 

[fsincox]

I do have them all!
"2X" goes back to 1982, 1973 was: ..... 2 holes.
Frank

 

[Enginerd9]

Yes, it has been. You missed what I was saying. I said they encouraged the use of that convention in updated standards due to the ambiguity caused by "typ." I never said the "X" wasn't also in those older standards. Read again.

 

[Enginerd9]

Also, adding a parenthesis around a dimension itself makes it a ref. dim, but adding a note after the dim in parenthesis does not.

"Dia. 9.00 (8)" says you have a diameter 9.00 hole located in 8 places.
"(Dia. 9.00)" says you have a reference diameter.

And, because I'm lazy, I'll give you a primer link to help your own research into the matter:

http://en.wikipedia.org/wiki/Engineering_drawing_abbreviations_and_symbols

 

[KENAT]

For example, "Typ." was standard in ASME Y14.5 1994

Where is TYP detailed in ASME Y14.5M-1994? Section 1.9.5 only talks about 'X'.

Posting guidelines faq731-376

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

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

 

[Enginerd9]

Trolls gonna troll.

I'm out, but to the OP: Good luck man, I hope you find what you're looking for.

 

[ewh]

Enginerd9,

Thanks but no thanks... I prefer to get my info from the source standard, not a site that lets anyone have their say (until someone disagrees). ASME does not own the rights to the only drawing standard out there, just the ones that much of industry in the U.S. (and this forum) follow.

I'm still stumped on how parenthesis around one number means reference but around another number doesn't. The only reference I could find is in the '94 version -
"1.7.6 REFERENCE DIMENSIONS. The method for identifying a reference dimension (or reference data) on drawings is to enclose the dimension (or data) within parenthesis."

A similar situation exists regarding "TYP". It is nowhere to be found in the section regarding repetitive features or dimensions (1.9.5) in the '94 standard, or in the section regarding former practices.

It seems that you may be correct about the "TYP" explanation, but I believe it was in the "Former Practices" section of the '82 standard where it was last mentioned.

If you have found another source for either of these issues in the Y14.5 standard (any year), could you please share it?

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

 

[ewh]

oops... too late I guess

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

 

[CheckerHater]

ewh,

It's the same in '09 version - "dimension or data"

But best of all in ISO:

 

[ewh]

Yes, ISO put it best.

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

 

[ModulusCT]

@Enginerd09: Thx for the support fellah.

To everyone else who contributed to this thread I would just like to say that I'm still here at this sporting good manufacturer located in Southern, & not Western mass and the checker has since been checked out of her position due to an inability to adapt to internal requirements.

I on the other hand, kicked ass all through December, taking everyone's advice, producing better drawings and learning A LOT from the people around me.... and I'm still here. Things seem to be going well. The checker from Hell is gone (A story for another day perhaps) and I feel like I've got a future here, should I choose to keep it.

The things that helped me most were, consciously double and triple checking my drawings, asking the checkers for help and probably most of all just telling myself that I was going to care about my job, our product and this position more than anyone else every day and then doing things that someone who felt that way would do really helped me out.

thx everyone.

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

 

[mdambros]

Great news ModulusCT! Glad everything worked out for you. I can't wait to see the new line of wiffle balls and bats from that sporting goods manufacturer in Southern, & not Western Mass!

 

[ModulusCT]

hehe thanks mdambros... There's still a lot to learn, but that's the good news!

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