How to creating a proper engineering drawing?
How to creating a proper engineering drawing?
(OP)
Hi, I have a new job where I need to take CAD models and create manufacturing drawings for the parts.
Are there any books that teach how to make a manufacturing drawing? I have a copy of the ASME standards, but they don't teach how to make a "nice" manufacturing drawing.
I don't want to bother the senior engineers with my questions about what needs dimensioning and what needs GD&T...
Anyone know of any books or resources I can use to help me??
Thanks.
Are there any books that teach how to make a manufacturing drawing? I have a copy of the ASME standards, but they don't teach how to make a "nice" manufacturing drawing.
I don't want to bother the senior engineers with my questions about what needs dimensioning and what needs GD&T...
Anyone know of any books or resources I can use to help me??
Thanks.





RE: How to creating a proper engineering drawing?
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: How to creating a proper engineering drawing?
Bother the senior engineers.
If they want this thing done their way, they are going to have to help you. They understand your company's requirements. Hopefully, they have had the sense to talk to your fabricators, inspectors and assemblers, and there is knowledge to be passed on to you.
There is no sympathy for know-it-alls who screw up.
RE: How to creating a proper engineering drawing?
Regards,
Mike
RE: How to creating a proper engineering drawing?
RE: How to creating a proper engineering drawing?
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: How to creating a proper engineering drawing?
I would interprete "looks good" to mean "functional". I only have one rule: if the machinist needs to stop the equipment, pull up an alternate source like the Machinist Handbook, ask a question or make a phone call, then the drawing has failed. Tell the man what you want and not how to do it!
I've found some really excellent textbook references in antique book stores, some dated back to 1897. I buy them just out of curiosity and see the history and development of the machining practice. Some pretty amazing stuff. Still, machines such as shapers and methods in hobbing gears are practical in today's age. Old book stores would be another avenue you could investigate.
Good luck with it, stay focused on functionality of the print.
Regards,
Cockroach
RE: How to creating a proper engineering drawing?
You bother the senior engineers..You study the companies existing drawings. You need to at least know design intent from the engineers. How the heck are you supposed to know what tolerances need to be applied/where,etc.. (hopefully this is in the models already..it should be)
You need to know how the parts will be made so you can put the correct information on the parts.
RE: How to creating a proper engineering drawing?
For the first, as suggested, review existing drawings. Chances are you will find an existing drawing that covers something new. Get to understand what the general notes mean, why they were used. Talk with those that will build from your drawing, get their input in case you need to add clarification. Rise, repeat.
For the second, you'll have to pick senior brains, no way around it, unless you designed it yourself. The application of proper GD&T is covered in forum1103: Drafting Standards, GD&T & Tolerance Analysis.
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RE: How to creating a proper engineering drawing?
To accomplish that, every feature needs to be located in three dimensions.
So step 1 is make sure that every feature is fully located.
The dimensioning and tolerancing scheme required has to do with how the part need to function.
[simplified example]If the relative location of two features is important, then the distance between them should be directly dimensioned, don't dimension them both to an unimportant feature just because it's easier to draw.[/simplified example]
So step 2 is understand how the part needs to function.
Drawings should define what you need. Not how to make it. However, it sure is useful to understand how things can be, and are likely to be made.
So step 3, go talk to machinists - good ones. If you don't have machinists, at least try to find a good estimator who understands how things are made.
Modern CAD tools all have "dimension shot guns". At the click of a mouse you can very easily scatter random dimensions over the entire drawing. This will result in a really crappy drawing.
RE: How to creating a proper engineering drawing?
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: How to creating a proper engineering drawing?
RE: How to creating a proper engineering drawing?
Models already exist and the OP takes them and makes drawings, thus I think it is safe to say that drafting does apply.
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: How to creating a proper engineering drawing?
RE: How to creating a proper engineering drawing?
RE: How to creating a proper engineering drawing?
and we should note his field, electrical, so he probably hasn't had much drafting instruction (if mech's get that these days).
GD&T would be a good place to start.
RE: How to creating a proper engineering drawing?
Regards,
Cockroach
RE: How to creating a proper engineering drawing?
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: How to creating a proper engineering drawing?
RE: How to creating a proper engineering drawing?
I guess that says it all.
P.S.: I didn't know "OP" was used here.
NX 7.5
Teamcenter 8
RE: How to creating a proper engineering drawing?
Technical Drawing by Frederick E. Giesecke, Alva E. Mitchell, Henry C. Spencer, Ivan L. Hill, John Thomas Dygdon, James E. Novak, Shawna Lockhart
Engineering Drawing And Design by Cecil Jensen, Jay Helsel, Dennis Short
HTH,
Dan
Han primo incensus
RE: How to creating a proper engineering drawing?
First off, look at the relevant standards.
Not just Y14.5. In fact I'd take a look at Y14.3 & Y14.24 before Y14.5 as they are more about drawing lay-out and how views are projected and what belongs on the drawings etc. Maybe even take a look at Y14.2 & some of the other 'lesser' standards as well as Y14.100 itself.
Read the first few chapters of Y14.5, not the tricky GD&T stuff initially but chapter 1 & 2 especially which give more general ground rules & definitions etc.. Section 1.4 'Fundamental Rules' is especially something you should know almost by heart.
Ask the seniors if you have any company specific standards to follow, or at least examples to follow. Try to find out who the real 'drafters' are as opposed to the engineers who half heartedly/grudgingly fudge it just enough to get by (most engineers will probably fall in this latter category from what I've seen) or the CAD monkies/jockeys that know what every button on the CAD does but can't create a decent drawing for the life of them.
If you are lucky enough to have a Checker, or at least a really senior drafter (or the rare engineer that really has a clue about drafting) who can spare the time to bleed (as in red pencil everywhere) all over your drawings then you are very fortunate - MAKE THE MOST OF IT.
forum1103: Drafting Standards, GD&T & Tolerance Analysis really is a good place than for this type of question as it covers most things drawing related - although there may be a few members there that tend to take things into the esoteric realm whenever possible
(And frankly, some of the suggestions above are laughable for "How to creating a proper engineering drawing" - many, perhaps even most, 'CAD Trainers' or standard CAD training courses from the CAD companies are more interested in 'what the software can do' than 'how you should use the software to create a good drawing'.
As for the self generated drawings, it's a case of serious GIGO - if you're lucky - the automatically created drawings usually need serious tweaking unless you were really careful when creating the models. Even then they usually mess up at least a few things.)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: How to creating a proper engineering drawing?
RE: How to creating a proper engineering drawing?
RE: How to creating a proper engineering drawing?