History of Design Drawings

[sentry7]

Hey guys,

So I'm a sucker for design drawings, schematics, diagrams, drafts - basically anything to do with plans for something to be built. I surmise that before computers and CAD, people with insane skills had to draw these things by hand. I've seen old, vintage, hand-drawn design work before and it looks just as impressive as any computer-aided design work. Are there any drafters, designers, or knowledgeable people who know how this work is done by hand?

[uncle_bob]

Hi

Of course it was done by hand. PCB layouts were done by hand in the same era. Been there / done that.

Bob

[sentry7]

I'm kinda terrible at wording this, but I guess I was more after "how" it was done. What were the tricks and the trade? What about tools? I guess I just want to learn more from the experienced folks who has done this kind of thing.

[uncle_bob]

I'm kinda terrible at wording this, but I guess I was more after "how" it was done. What were the tricks and the trade? What about tools? I guess I just want to learn more from the experienced folks who has done this kind of thing.

Hi

Well, you took a number of drafting courses and quite possibly a technical illustration course or three. The starting point was a very conventional set of 3 view drawings of each bit and piece for the mechanical stuff. The starting point for the schematic was a hand drawn version. The drawing you show on the bottom is more an illustration than a drawing.

In each case it was a sit down and grind it out process. You had rooms full of people that did this sort of thing.

Bob

[station240]

For commonly used symbols/letters they sometimes had templates. Basic construction is a sheet of material with cutouts to draw in. eg resistor would be the squiggle, the diode had the bar and a triangle cutout (hold pen in such a way as to push towards the edges of the hole).

Also the diagrams were drawn larger than required, and reduced in size by using photographic techniques.

[uncle_bob]

For commonly used symbols/letters they sometimes had templates. Basic construction is a sheet of material with cutouts to draw in. eg resistor would be the squiggle, the diode had the bar and a triangle cutout (hold pen in such a way as to push towards the edges of the hole).

Also the diagrams were drawn larger than required, and reduced in size by using photographic techniques.

Hi

Various outfits also sold little stick on symbols you could use. In all the years I saw things being done this way ... it was a hand process. There were no stickers or other gizmos used by the guys who did this for a living. The stickers and stuff got dismissed as "junk for amateurs ". (actually the words used were not quite that polite).

The stickers and tape did sometimes get used in pcb layouts. They had a short shelf life so anything important got re-done in India Ink after the first pass.

Bob

[HAL-42b]

The hidden trick you are looking for is the humble tracing paper

These drawings do not come together in one go. They are built in stages and mistakes or changes happen often. It would be a nightmare for the engineer to have to redraw an ink drawing every time.

So the initial drawing is done with pencil. Errors are corrected, things are added or removed and so on. After everything is ready a tracing paper is laid over the initial sketch and the whole thing is redrawn in ink. Many separate pencil sketches may come together to make a final ink composition.

There are many types tracing paper. From cigar paper thin to very thick, semi transparent to fully transparent, ordinary paper or synthetic, cheap and expendable to archival quality.

I remember using mainly thick synthetics because they did not warp with moisture from the hand and it was possible to erase ink using white spirit instead of scraping it off with razor blade.

The tracing paper was like the layer and versioning system of old. The concept of layers we have today is based on it. You can stack several layers of transfer paper to make up the final drawing. There are also other nifty things like rotation or reflection that were possible.

Ah memories...

[uncle_bob]

Hi

Mylar sheets were (by far) the most stable way to do layups.

Bob

[HAL-42b]

Hi

Mylar sheets were (by far) the most stable way to do layups.

Bob

We rarely used them in architecture. They had this tendency to dent when laid over a piece of grit. Also they were far too transparent for manual tracing. You couldn't see where you've been unless you use different color ink.

They were mainly used for optical copying and projection work, like electronics.

[uncle_bob]

Hi

Mylar sheets were (by far) the most stable way to do layups.

Bob

We rarely used them in architecture. They had this tendency to dent when laid over a piece of grit. Also they were far too transparent for manual tracing. You couldn't see where you've been unless you use different color ink.

They were mainly used for optical copying and projection work, like electronics.

Hi

They pretty much were the "standard item" for electronics. Punch holes to line everything up and you can distribute the layers out for mods.

Bob

[sentry7]

Wow...extremely interesting stories and work experience; I really think this is the coolest stuff ever. I'm 24 and almost out of university, so I don't know about how this work was done back then. Of course, I imagine that the proven methods are still used, just not as often as CAD. Personally for me, I feel like a lot of artfulness is missing from engineering today, but it's the old age quality vs. efficiency dichotomy.

[uncle_bob]

Wow...extremely interesting stories and work experience; I really think this is the coolest stuff ever. I'm 24 and almost out of university, so I don't know about how this work was done back then. Of course, I imagine that the proven methods are still used, just not as often as CAD. Personally for me, I feel like a lot of artfulness is missing from engineering today, but it's the old age quality vs. efficiency dichotomy.

Hi

Today you have two or three guys on computers doing the work that thirty or forty guys used to do. There is a lot less manual checking and a far faster work flow. You also have a lot more ability to start from vendor supplied models than you ever did "in the good old days".  Today you do things on 16 to 24 layer boards in one pass that would have been impossible with the old tools.

I'd never swap a modern computer based system (with pro grade tools) for the "good old way".

Bob

[Halcyon]

I'd imagine stencils would feature heavily when drawing symbols.

[Len]

You had rooms full of people that did this sort of thing.

[HAL-42b]

In architecture you have to do both. You have no choice.

Even today when a fresh student enters the studio for the first time he or she knows neither hand drafting nor CAD and they have to learn both, simultaneously.

You will never grasp the basics of geometry unless you slog on a piece of paper. At that stage CAD just gets in the way and is limiting in very sinister and subtle ways. You need to have the least layers of abstraction between the idea in your head and the paper.

The most valuable thing I learned in my life was to sketch freehand. All intermediate layers removed. This is orders of magnitude more powerful than any technical sketch or CAD tool. For anyone striving to do design the freehand sketch is the one skill that trumps all else when dealing with abstract ideas.

[uncle_bob]

I'd imagine stencils would feature heavily when drawing symbols.

Hi

Less than you might think. You got *very* good at doing things with standard drafting tools. The wires all had to go in that way and the lettering as well. The time saved with gizmos was often not worth the effort to maintain an inventory of a few hundred items and track down this or that symbol when you needed it. Remember .. the symbol template for 1:1 is different than 2:1 or 2.5:1 or ... Thus lots of inventory for not a lot of use.

Bob

[HAL-42b]

You had rooms full of people that did this sort of thing.

Far too rigid and orderly for something creative to come out of

In my opinion the level of general disarray should be something like this




And you thought Jim Williams was something
(Harvard Graduate School of Design for those wondering)

[Farley]

To get an idea of the tools used prior to CAD you can Google "Drafting Table", "Drafting machine", "Drafting Triangle", "French Curve", and if you want to go back even further - "T-Square."

The schematic the OP posted is most likely done in ink and the lettering was likely done with a Leroy lettering set.

I started my career as a Draftsman. At my first job the drawings were done in pencil on vellum then the pencil lines were inked over. Inking came to a halt when I took over the department.  From that point forward the drafters (the term draftsman was inappropriate since I had several female employees) were trained in the technique of how to use pencils of appropriate hardness to draw object lines, dimension lines, witness lines, etc. A properly trained drafter/engineer can create amazing drawings with pencil on vellum. The manual drafting process has a certain amount of art to it as well as technical skill.

[vk6zgo]

Even such simple things a car manuals (especially Brit ones) had detailed line drawings.
Nowadays,you get a blurry third generation photo!

[CatalinaWOW]

Two other tools important in this era were the eraser shield and electric eraser.  At least for the mere mortals among us.  Also don't forget the enormous drawing files.  Cabinets the size of a kitchen table with multiple shallow drawers to hold D and E size drawings.

Just like today there were those whose talent showed.  In all of the drafting departments I worked with there were a small percentage of craftsmen/artists who did the fancy stuff like cut away drawings and the like. 

[HAL-42b]

Found a little course that explains the general principles.

[Alex Eisenhut]

I like the early computer stuff.

https://en.wikipedia.org/wiki/DAC-1

https://history.gmheritagecenter.com/wiki/index.php/GM's_Road_to_Virtual_Product_Development