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I am studying a bunch of stuff related to mechanical engineering and am considering an eventual switch to the field after taking the necessary classes. I'm older, and I took drafting classes in high school and part of college. I'm familiar with the standard drafting procedure with paper, as well as AutoCAD, and these days SolidWorks. It's a shame they don't teach paper drafting much anymore!

But I am left with a question I don't have the answer to, nor the resources to answer it. These days it seems most mechanical engineers (at least the ones I know) are really performing the role of both the drafter and the engineer.

Prior to 1995 when SolidWorks came about, what was the duty of the mechanical engineer? If we go even further back before CAD was invented, what duties did a mechanical engineer perform?

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    $\begingroup$ There are many mechanical engineers that don't draw a thing. It's a pretty broad discipline. If you are limiting yourself to design engineers, then we used other CAD packages before Solidworks. Solidworks wasn't the first solid modeling program either. $\endgroup$
    – Eric S
    Nov 28 '21 at 21:52
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    $\begingroup$ @EricS i suppose the real heart if the question was, how did engineers design before any form of CAD. $\endgroup$ Nov 28 '21 at 22:12
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    $\begingroup$ a pox upon thee for suggesting they bring back drafting! $\endgroup$
    – Tiger Guy
    Nov 29 '21 at 16:52
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    $\begingroup$ I liked drafting (when I took it as an elective in high school) :) $\endgroup$
    – chepner
    Nov 29 '21 at 20:16
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    $\begingroup$ Conversely: "How did software engineers work before StackOverflow?" $\endgroup$
    – Dai
    Nov 30 '21 at 10:29

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At the beginning of my career (1979) as a design engineer at HP, the mechanical engineer created the part design and then rendered it in pencil on paper, and then transferred it onto sheets of vellum paper held onto a huge flat tilting table called a drafting board which had a precision sliding arm on it with which parallel and right angle lines could be drawn anywhere on the sheet.

Clever graphical rules were applied to the resulting drawings which permitted auxiliary views of the part to be generated so it could be viewed from any desired angle, as an aid to the machinists who made the part in accordance with the drawing. Clipped onto that arm was a handy HP handheld calculator with which the engineer kept track of cumulative dimensions as he (all of them were "he") worked his way across the paper sheet. Some of these "he's" also attached their ash trays to the drafting arm so they wouldn't get cigarette ash on the vellum.

You'd come into work, sit down at the drafting board, and stare at the three views of the part you had drawn for half an hour or so to get it into your head, and then pick up the pencil, put a nice sharp point on it with a mechanical sharpener, and then proceed drawing where you had left off the previous day. Coffee helped.

The outlines of the part were drawn with one thickness of pencil line, dimension lines with a very thin line and arrowheads done thickly in softer pencil lead to produce a nice dark effect.

Erasing was done with a device like a dremel moto-tool, in which a hand-sized electric motor spun a chuck holding a stick of rubber eraser material.

Stress analysis was done by hand and parts interference problems were worked out in collaboration with the machinists in the model shop.

It was a simpler time, but the work was much more tedious and time-consuming than the design process used today.

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    $\begingroup$ A friend of mine from another forum talked about designing the USS Eisenhower aircraft carrier. The General Arrangement prints were over 100 feet long - hand drawn. It was a long walk around to the other side to go get coffee. $\endgroup$
    – Phil Sweet
    Nov 29 '21 at 23:18
  • $\begingroup$ I'd trade the cigarettes for some other vice but outside of that that sounds idyllic. $\endgroup$ Nov 30 '21 at 11:20
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    $\begingroup$ @AdamBarnes It's only idyllic in the best case scenario. Changes will piss you off and make you really cranky, real fast. $\endgroup$
    – Nelson
    Dec 1 '21 at 1:58
  • $\begingroup$ @PhilSweet I can totally imagine someone building a bridge to get over the plans :) $\endgroup$
    – Criggie
    Dec 1 '21 at 5:29
  • $\begingroup$ Pocket calculators? That was the beginning of the end of real engineering ;-). $\endgroup$ Dec 1 '21 at 9:43
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In the offices I worked in, drafters were also expected to have a grasp of the trades required to build the thing they were drawing. They'd have some background in welding, fitting, and fabrication. They were expected to draw something that was a) faithful to the mechanical engineer's design, and b) practical to build. We'd often get comments from the drafters like "You cannot fit a hand plus welding torch in there."

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    $\begingroup$ The draughtsmen I worked with until about 10 years ago had all gone through an apprenticeship route so had learnt a lot of the skills needed to build their designs. They kept their hands in by working on prototypes (but we were a small-volume/customisation group). Those of us who came in as graduate engineers had a lot to learn around things like designing for manufacture, and those skills are valid whatever drawing tools you use. $\endgroup$
    – Chris H
    Nov 30 '21 at 13:04
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    $\begingroup$ When I was an undergraduate engineer, in our first year we were required to do both general math and science at university, along with basic drafting and workshop at the local technical/trades college. $\endgroup$ Dec 1 '21 at 1:02
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    $\begingroup$ @ChrisH that's a process all automotive engineers should be required to go through these days. In the name of "packaging", it seems any automotive service beyond a simple oil change requires an engine removal or at least 3 elbows, 2 wrists, and forearms the diameter of a newborn infant. :( $\endgroup$
    – FreeMan
    Dec 2 '21 at 13:42
  • $\begingroup$ @FreeMan In some models to change a headlight bulb you're supposed to jack the car up, remove the front wheel, and the wheel arch liner. I'm not sure how they get away with that one - strictly speaking you should get towed to a garage for a blown bulb. But in general there's far too little trust placed in hands-on experience. $\endgroup$
    – Chris H
    Dec 2 '21 at 13:49
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I think the duties that engineers have to perform are independent of the tools they use. Nowadays there seems to be a trend that everybody involved in a working process, regardless of if we are talking about research and development, design, manufacturing or service, relies too much on CAD (or any other software tools) itself.

A good working process, and a good technical solution, is independent of the tools it is created with. Of course, CAD and/or ERP tools are a very important aspect, and you can't compete without them. No doubt. But as long as the working process as a whole has drawbacks, the CAD tools will not lead you to success by themselves.

Thus this is the true duty of a real engineer: to create, lead and develop a process that works in all aspects: the people, the product, the (CAD) tools. An engineer's job is to develop knowledge and give it to the people, create a working structure in which both the product as well as the employees can evolve. If CAD is needed for that, it must be used. If all that is said does not work, CAD alone won't fix it. There were brilliant engineers that created solutions on a sheet of paper, and there were others that produced CAD modeled solutions that looked brilliant on screen, but not more than that.

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But I am left with a question I don't have the answer to, nor the resources to answer it. These days it seems most mechanical engineers (at least the ones I know) are really performing the role of both the draftsman and the engineer.

IMHO Solidworks (and other similar products) for the engineer today are much like a scientific calculator back in the 1980 and 1990. I.e. they are a tool that can speed up their lives and give them access to workflows that were not available before. Nowadays with solidworks you can think something and you can do a very quick (and relatively accurate if you know what you are doing) analysis and see whether the part or the assembly you are building performs the function you intend.


Short interlude: Before the scientific calculator, you had the slide rule.

enter image description here

(The slide rules went out of use just when I started my mechanical engineering education so I never got to use them, but I got one in mind condition).

The transition to the calculator (to me at least) seems like going from the calculator to Static or dynamic Finite Element analysis in solidworks.


As an added bonus, Solidworks can also prepare drawings of the part. However, in many cases nowadays even the 2d drawings are being (slowly) replaced in certain industries by 3d models or stl files.

So, IMHO, Solidworks or Invertor isn't about drafting, is more about a generic tool that can help an engineer (manufacturing, electrical, mechanical, industrial) to achieve more and communicate better.

Prior to 1995 when solidworks came about what was the duty of the mechanical engineer? If we go even further back before CAD was invented, what duties did a mechanical engineer perform?

A mechanical engineer can have many duties which are totally unrelated to drafting.

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  • $\begingroup$ Round here (one-off jobs in a university) milled parts are CNCed from Inventor files, but turned parts are still made manually to a drawing. The drawing is still useful for the milled parts: for discussion, for ordering material, and for checking various mating features, but we can often get away without dimensioning every last feature. Then of course there's 3D printing, where the job could theoretically go from model to solid plastic without human intervention. In practice generating a drawing from the model is a worthwhile step, a tool used for reasonableness checks $\endgroup$
    – Chris H
    Nov 30 '21 at 14:47
  • $\begingroup$ @ChrisH and documentation $\endgroup$
    – joojaa
    Nov 30 '21 at 17:32
  • $\begingroup$ @joojaa not such an issue here, but a good point in general - and paper/PDF isn't subject to the whims of support for old versions $\endgroup$
    – Chris H
    Nov 30 '21 at 22:10
  • $\begingroup$ :-) ... And after the slide rule ... the mechanical "calculator" ... which one had to turn, turn ... and turn ... :-) $\endgroup$
    – Antonio51
    Dec 2 '21 at 13:03
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We didn't have to ask how to use our tools.

This SE is filled with how do I... for Solidworks, Abaqus, Ansys APGL...

I guess we spent more time drawing and calculating, versus figuring out how to make software do it. We probably also got a lot less done.

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    $\begingroup$ I think thats not really any indication of what people do. Beginners exist everywhere. Even with pen and paper you would have questions like this. $\endgroup$
    – joojaa
    Nov 30 '21 at 7:12
  • $\begingroup$ @joojaa, I don't think many people need to ask how to use a pencil $\endgroup$
    – Tiger Guy
    Nov 30 '21 at 15:52
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    $\begingroup$ well youd be suprised how much you can teach about a pencil to a beginner. But thats beside the point then they would ask about using a slide rule or tabular result. $\endgroup$
    – joojaa
    Nov 30 '21 at 17:29
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The mechanical engineer actually designs the thing.

The draftsman's job was to render the engineer's intent in a drawing which is clear and unambiguous.

So the engineer can say "yup, that's what I meant" and the fabricator can say "yup, I can build that".

And here's the important thing: when the part doesn't work out, the drawing decides who screwed up and who pays. (Often the engineer and fabricator work for different companies.) if the part matches the drawing, the engineer pays, otherwise it was misfabricated.

There may still be a place for the draftsman, as the engineer may not have the time or inclination to do all that fiddling in Solidworks, which can be quite time-consuming even if it is faster than paper drafting.

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Engineers designed and sorted the calculations defining the components - material, size, etc.

Draftsmen did the drawing pencil on paper or ink, then did blueprints.

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    $\begingroup$ Draftsmen are technicians; I worked as a draftsman one summer after my first year of college, it was educational. I think the guy that checked drawings was an engineer. $\endgroup$ Nov 28 '21 at 21:51
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    $\begingroup$ We work this way, the design engineer provides the rough sketch, notes, and remarks, then the technician or senior draftsperson adds necessary details per company standard and gets the drawing developed/drawn. The review is in the reverse order, all the way up to the supervisor of the engineer/lead engineer for important jobs. $\endgroup$
    – r13
    Nov 28 '21 at 22:32
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I work with lot of architects and design school graduates and students that still work without computers. There is really nothing wrong with doing it this way except that it neccesitates sometimes having somebody else make your drawings digital. Nothing like having to convert a carboard mockup to 3D model.

The way you do this is by taking a sheet of paper and start drawing. Then after you got a rough idea you draw more just to be sure. Then you draw a clean drawing on top of that. But by not having a CAD also frees you, you can bend sheetmetals out of cardboard, you can sculpt stuff out of modeling clay, or sand out of a block of polyurethane.

You might spot at this point that the downside is that any small change and youll be redoing things. A lot. I used to work with a older person who had been a draftsman who said that he basically drew one drawing a day, only to start over next day for a trivial change.

Now while this is a bit bad for job productivity, theres also some advantages of working on paper. The problem with MCAD software like solidworks is that its designed for the detail work stage. The problem that raises with this is that it railroads you to thinking certain ways. Having paper sketches is a way to combat this thing. But it has advantages too, it lowers your cost, having a extra draftsperson is expensive.

It is true that the CAD application has in a way killed the drafing job. But please note, it is culturally dependent, in some parts of the world the engineers did their own drafting even before the advent of CAD applications. Today even if companies want to have somebody to do just the technical drawings, they can not easily find draftsmen (this is to my understanding much more a european problem). So if you want to have somebody you have to have a junior person doing this. This isnt ideal as a senior person would take care of other details too.

Which brings us to the second person that the modern CAD application also killed off many of the modelmaker positions. So it used to be that you submitted a functional drawing to a modelmaker and they would just add drafts etc etc. Also you have a lot less people in general these days. So the CAD application really kills of 2-8 persons in the loop depending on how far back you look back.

The problem with having a extra person in the loop is that the change I want takes one day, while if im modeling myself it takes often less than a hour. But then i have more chances for screwups.

To answer your final question enfineers had mostly the same duties as they have today, using the cad is just a extra tool layer on top. Not all mechanical engineers draw in CAD.

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  • $\begingroup$ Heard a story about the Morris Minor when it was being designed - later stages, that the Boss thought the proportion was wrong so 2" was sliced vertically out of the full size clay model to reduce its width. Then ok, that was the design sent to production. $\endgroup$
    – Solar Mike
    Nov 29 '21 at 16:36
  • $\begingroup$ @SolarMike they werent doing much to manage thumbprint clients? Yeah i heard this too $\endgroup$
    – joojaa
    Nov 29 '21 at 16:52
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Mechanical engineers that do not know about Solidworks yet in these days start from FreeCAD.

When I attempted to create my own startup and suddenly needed to 3D print a few parts, I knew nothing about Solidworks. I quickly googled and found FreeCAD that was free and able to run on my Linux. If was definitely not sugar, especially taking into consideration that I had no any experience at all, but at the end produced the STL files I needed. The parts were printed OK.

P.S. I am not affiliated with FreeCAD. Maybe this answer still could be seen as an irrelevant promotion but then I wonder how the question is not.

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CAD tools can define parts, check they fit together, and check whether the design fails in some way (e.g. stress exceeds acceptable limits). They can't answer the less black-and-white questions a design engineer (in any discipline) should be asking:

  • Is this actually going to work:
    • Can the part be made (as others have said)?
    • Does it meet all the project requirements, including the non-engineering ones (like aesthetics) which may not have been formally captured?
  • Is there a better way to do this (where better involves weighing up lots of considerations, technical and commercial).

The other open-ended question a development engineer asks is "what should this do?" - and CAD is rarely involved in that question, even if it is very valuable in evaluating the answers.

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