huangyhg

degradation of drawing standards
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...

check out our whitepaper library.
chancey:
i am in agreement with you totally.
i do a lot of training in gd&t and also blue print reading. i re
every drawing i see from every vendor i deal with is crap.
some are less crappy and some are more crappy - but all are crap.
chancey, i agree (well maybe not on the hidden line thing) and i too don't date back to using a drawing board in anger.
i was brought to this company as part of a team trying to improve this. it's been a long hard struggle and now it appears we may have finally lost.
despite proving the benefit of higher quality drawings/checking by reduced eco count on programs that were checked it appears we may have lost the fight.
we've been suffering in the current economy as well as some questionable management decisions and now managements big idea seems to be to give our vendors any old crap drawing and expect them to fill the voids because 'they're hungry'. how the #@$%#$%!#$% they're meant to know the design intent, required tolerances is beyond me & it's all tied in with wanting to outsource/offshore more and more work.
i think our ceo's wet dream would be him as the only us employee just having to phone the relevant subcontractor in whatever country he can find the cheapest sweat shop.3
rant over..... for now.
kenat,
drawing standards are not taught in school and managers that are not experienced in engineering or drafting don't care or don't know about them.
therefore, a don't care or lazy attitude take precedence.
with jobs being global now, standards are mixed and some become overwhelmed or confused, sometimes raising costs for various reasons.
i don't see it getting better in the near future.
chris
solidworks/pdmworks 08 3.1
autocad 08
the standards are the same. compliance is dwindling.
i agree with everyone else on this. not sure how to enforce it though as many don't see the problem.
amen, amen and amen. a mend is virtually imposssible.
this subject has been visited many times before on these fora, and it's true. with the advent of cad, management figured that the engineers could now do their own drawings, as the required skilss for board work were no longer necessary. the only areas that this is true are maybe line work, lettering and descriptive geometry. they neglected to factor in the ability to put a lot of information in a small area, keeping it easy to understand and not open to varying interpretations.
i am currently checking a mold drawing and design created by a contract engineer. it is obvious he does not understand gd&t basics. he used first angle projection, odd scales, lower case lettering, included unnecessary fabrication instructions, used vertical text, unassociative dimensions, poor tolerancing, etc... and i have found this to be quite common.
the basic design, however, was good. the only thing i found that i would change is a #10-32 threaded hole he made 1" deep for a shear application.
i spent enough time on the board and had enough blood spilled on my drawings to have an appreciation of a good drawing and you're right, they are becoming rarer than hens teeth.

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."fff"> - george bush, washington dc, 27 october, 2003

was drafting ever rigorously taught in college? i recall being taught the basics. my present knowledge comes from reading all the literature i can get my hands on, including the standard itself, and taking extra courses.
how many companies and organizations have mechanical design and drafting as their primary expertise?
i suspect that many if not most companies were started by product experts or salespeople. mechanical design got added later. a major problem with mechanical design is that it looks easy. everybody understands what plates, gear and screws do. there is no need to start off your mechanical group by hiring someone experienced and competent. by the time someone experienced and competent gets into the office, standards have become low.
about twelve years ago, i was sent out for unix system administration training, so that i could manage the cad stations. once i got into the administration stuff, i was amazed at the complete lack of supervision. everyone tried to micromanage my mechanical stuff, at which i had more than ten years of practical experience. my system administration was two weeks of training plus a month's experience, and i could not get supervised even if i wanted to.
jhg
nothing like opening pandoras box. it takes the sting off a bit knowing that others share in the pain!

__________________
借用达朗贝尔的名言：前进吧，你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]