Drafting Equivalent of Texting

[truckandbus]

Anybody notice adherence to drafting standards degenerating over the past few years? It is as if the same attitude seen towards spelling while texting (ur instead of you are, l8tr instead of later, etc) is showing up on the drafting boards (hidden lines missing from views, hole common centerlines implied but not shown, etc.). I've recently changed companies and I'm stunned by the lack of application of standard drawing practices. The common explanation seems to be 'the parts are made from the model anyway, not the drawing)

 

[Nereth1]

Yes I've seen it, even been at odds with people because of it. In fact I have had an intern sigh and tell me I was being so pedantic/annoying/wasting paper (had him print it each time) when I redlined too much. Which blew my mind because half the problems were actual mistakes that would have meant rework for orders of magnitude more time than fixing the drawing itself. And yes I have had to put my foot down (to raised eyebrows no less) that the views that show the part (with the possible exception of an isometric view) must have hidden lines shown or it just isn't a damned engineering drawing. If the mess of lines makes it unclear, you need to rethink your views, not rethink the lines.

Where I work we have people working on production parts which are just variants, and all the tolerances and details are known to the machinists, and we have people (like me) working on tools and machinery for production which must get sent out and manufactured. There is a divide between the drawings I make, which must fully communicate a part, and the drawings made for production, which need only really indicate things that are different from the norm. When either side dabbles in the other sides area, there is friction.

 

[JNieman]

And yes I have had to put my foot down (to raised eyebrows no less) that the views that show the part (with the possible exception of an isometric view) must have hidden lines shown or it just isn't a damned engineering drawing. If the mess of lines makes it unclear, you need to rethink your views, not rethink the lines.

That would have raised my eyebrows too. The way you state it, you sound like you care more about adhering to some standard blindly (Which standard says hidden lines are /required/ again?) rather than trying to keep your eye on the goal which is efficient, clear communication which defines the part fully and without alternate interpretations possible.

_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5

 

[CheckerHater]

There is a divide between the drawings I make, which must fully communicate a part, and the drawings made for production

I've seen that and it looks like yet another slippery slope to me. In today's world where moving production from Mexico to China is getting as easy as moving to the shop next door "in the house" drawings are easily becoming "outside" drawings and vise-versa.
Maybe you should redirect your energy into making ALL drawing in your company “fully communicate a part”?

Just a thought

 

[LONDONDERRY]

I don't believe showing hidden lines is a requirments. Personally I rarely show them, unless needed, and for the following reasons:
1. In 2d CAD many times esp. in sheet metal, I've accidently snapped a dimension line to a hidden line and even after checking the drawing it was sent out for fabrication and came back wrong..
2. Too many hidden lines in a view makes a view over complex to understand

 

[ewh]

This issue has been discussed here numerous times and many agree that, since CAD, drawing practices have been falling.

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

 

[Nereth1]

JNieman,

You know, you may well be right in that comment, and at some point I will find removing the lines to be optimal as well (I'll check the standards first though), but none of the parts involved in what I am referring to were particularly complex or required that decision. Rather, they needed less, and larger (scaled) views so that information was more easily readable, and that was facilitated by using hidden lines to show details that would otherwise be invisible on the lesser number of views.

CheckerHater,

That's a soap box I've been on and chosen to get off for now - I am not the one scheduling or distributing resources on that side, I don't know how much time they have to be making more complete drawings, and ultimately I don't have the experience in doing it myself to have a particularly defensible position one way or the other.

 

[CheckerHater]

Understood.
I am trying to push for using standard ways of doing things myself with little results.
Even though we are occasionally getting burned for sending "internal style" drawings outside, "we always did it this way" attitude prevails.

 

[truckandbus]

25 years in industry and at least 1/3 of that time responsible for documentation control and drafting standards and I had never seen anything like this before. Happy(?) to see I'm not alone in observing this.

 

[ctopher]

I have seen it, but not only in Drafting. It's everywhere.
People have become lazier at spelling and grammar. Schools don't push it. Drafting is not taught.
I have been doing drafting for a long time and I make a point of following all standards, and chek speling.

Chris, CSWA
SolidWorks 14
SolidWorks Legion

 

[TheTick]

I worked as a machinist making parts to order before CAD got big. There were plenty of craptastic drawings back then, as well.

 

[LONDONDERRY]

Drafting is a dying profession that was killed off
I have my drafting degree and worked 3 years as a drafter then in 1991 that mini resession changed everything for me. I went back to college and got my engineering degree, and since then I have yet work at a company that has a drafting department or a drafter. Companies in general paid off entire drafting departments becasue CAD, the internet and running lean has killed off that profession all togther, in fact most comminuty colleges removed an AS in drafting and downgraded it to a certificate.

But convince me why I need a drawing if I need a rapid prototype and don't care about tolerances?

 

[KENAT]

truckandbus there have been lots of threads before touching on this topic - or the opposite side such as thread732-222977 & thread730-221206.

As Tick says crummy drawings existed before CAD & Engineers doing their own drafting using it - though it may be that they are more prevalent now.

A couple of thoughts:

1. At least some Engineers see drafting as below them.
2. Many Engineers probably got little or no drafting training at school/uni.

(As to the whole hidden line thing I'm missing something clearly. I make minimal use of hidden lines and am not aware of an ASME std that says to use them as much as possible. ASME Y14.5M-1994 1.4 (g) talks about only dimensioning to visible outlines & Y14.3 talks about not normally showing hidden lines behind cutting plane of section views. 14.3 does show a lot of hidden lines in its figures for what it's worth.)

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[dgallup]

* I never show hidden lines unless they are necessary. Always showing hidden lines is bad drawing practice, they just add clutter.

* All drawings should be fully dimensioned & specified.

* Proper use of CAD makes for better drawings then manual because all the views update automatically. I have seen 30 year old hand drawn assembly drawing that bore little resemblance to current production because every part had changed but no one wanted to redraw the assembly.

* Training of engineers in drawing practice has never occurred at most universities. Sure there are plenty of technical schools etc. that teach it but not universities. It's something that used to be taught by companies when they hired engineers out of school.

* Kids these days are a bunch of snot nosed punks (enter what ever 40 year period of time you want).

* Get off my grass.

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[Nereth1]

Yes as I said with hidden lines, as soon as he mentioned it I realized he was probably right, as I had never read it in a standard but it was just something I had always been trained to do - that said, hidden lines really shouldn't be underestimated, for me at least they help orient things in my head and when some are missing things can get unnecessarily confusing quite fast. I've seen more than a few drawings that would be fine but for missing hidden lines meaning I couldn't fully see what the part was.

 

[KENAT]

"but for missing hidden lines meaning I couldn't fully see what the part was. "

In that case I'd suggest perhaps they are missing views rather than necessarily lacking hidden lines.

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[ajack1]

Whilst I cannot speak for every CAD package out there I would say views generated from a model are far more accurate than they have ever been.

They are exactly what you would see for any given view or section. Whilst a strength this is also a weakness as you either have an all or nothing approach with things like hidden lines, at least on any package I am aware of.

What the old school drawings were very good at, at least the best ones, was showing enough to trick the person viewing them that all the information was there, whilst actually providing all the information that was needed.

If you actually look at many old drawings they are not true representations of the actual part at all, if you model a part from a hand drawing and then generate 2D views you will often see how bad they really were, but still look better to the eye and provide enough information to manufacture too as they looked far less cluttered.

 

[Nereth1]

Kenat,

That can be a matter of opinion. For example I prefer a lot more information on single views, it helps me orient the part in my mind a lot easier, and it also can avoid having to dart back between multiple views and sort of daisy chain dimensions together to find where things are placed. Less views on the same paper can also mean larger scaled views, which is nice.

Ajack,

I'm not sure I follow your second set of comments- "showing enough to trick the person viewing them that all the information was there, whilst actually providing all the information that was needed." Why would you need to trick the person that all the info was there, if all the info needed was indeed provided? No trickery there. Not sure I understand your last section either. Are you saying drawings were not to scale and this was used to make them more clear? All the "oldschool" drawings I have seen (admittedly not many) that were decent/intended for longevity have been mostly scale.

Also while no hidden lines may be acceptable as I would know not to rely on them,if there was a mix of hidden lines shown and not shown I would probably start making mistakes in interpreting, or at least get slowed down really far and just needing to confirm with whoever drew it that there were not just mistakes in projection etc. Do you guys actually use inconsistent hidden line presence in drawings?

 

[ajack1]

To see what I am trying to say Nereth1 look at an "old school" drawing of a cast part with lots of fillets, sweeping curves and draft angles on it, then look at a drawing generated from a 3D model.

One is an exact representation of what you see and one is not but tricks the mind and the one that is wrong actually looks better to the eye.

 

[truckandbus]

I think that in the 'old days' when you had a crappy drawing, everyone would agree you had a crappy drawing that violated standards and somehow got by the checkers. I find today that you get into arguements with people defending a poorly constructed drawing, and that standards are applied inconsistently and without explanation. When you look at a drawing and and it is missing geometry how do you determine if it was intentionally done on the part of the designer? Old school, if it was determined to be neccesary to deviate from standard practices, wouldbe to annotate the view 'hidden lines omitted for clarity"