Join Paul F. Aubin for an in-depth discussion in this video Exploring technical drawings, part of Drafting Foundations.
- I attended architecture school in the mid 1980s and at that time, we were still very much immersed in the paradigm of drawing boards, parallel rules, and manual drafting. We worked on large sheets taped down to our drawing boards to keep them from moving around and used many specialized drafting tools to create these drawings. To learn how to create drawings, we relied on tips from professors, other students, and a few books on the subject. The most popular one was Architectural Graphics by Frank Ching. It was the go-to book for creating architectural drawings and I still have my copy of it right here.
What I like most about Ching's books was all the very clear illustrations that he used and the fact that everything was hand lettered. We actually used to debate whether or not he actually lettered them himself or whether they used some sort of computer font to simulate the hand look. Wouldn't be much of a debate today. As I graduated, it was at the very beginning of the age of computer-aided drafting, or CAD. And so I experienced traditional hand drafting and computer drafting first hand early in my career.
Mr. Ching's book has evolved along the way with the industry and I have one of the more recent additions right here, which discusses both traditional and CAD methods throughout. Now sadly, they've replaced the hand font with a more generic computer-generated version. But I'll take Mr. Ching's lead here as we discuss both traditional hand drafting techniques and explore some of the computerized alternatives throughout this course. The main goals are to be sure that you understand what drafting is, why it's important, and what techniques are important and transcend your choice of tools.
Let's start with some examples. While preparing for this course, I climbed up into my attic and located a few of my earliest drawings to share with you. Now I have here something that's drawn on trace paper. We would use this very simple trace paper to do hand sketches that we would use for working out designs. Now hand sketches can also be supplemented by computer sketches, so here I have a few product designs that you can see several different views of a product as the designer begins trying to workout what that product might ultimately look like.
Now, sometimes they're done on a computer like those examples and sometimes they're more hand-drawn like this example of a chair here, where we're seeing a front side and a top view. Very common to kind of explore the items in various views like that. Now when it comes time to start making the design a little bit more finalized in the hand drafted days we would work on this vellum or Mylar sheets. Now, I have vellum here, Mylar would be similar, but they're transparent sheets that you create the more hard line version of the drawing.
Right here, I have an illustration of a floor plan, this is actually one of the first apartments that I lived in when I got out of college. Now here's a set of drawings that is for a renovation in a person's home. There's several elevations here for the various work that's been done. You can see that all of it is annotated with dimensions and notes calling out what's happening in each of the drawings. I have elevations there. There's some detailed views here of a deck and a patio. Might even have some 3D illustrations or a floor plan like you see here.
Now perhaps you're wondering why the sheets were all this transparent trace paper. Well, one of the primary requirements of drafted drawings is they need to be shared with many people. The transparent sheets facilitated this. Most of the drawings were these large format sheets, even larger than the ones I've shown you here, and in order to make copies of those, we used a process called diazo. Now diazo was a process where you would sandwich the sheet with a piece of photo sensitive paper and feed it through a machine and it was exposed with an ammonia solution.
The earliest version of that would generate these types of drawings here, that of course, you've probably heard of before. These are called blueprints. Now the reason they're called blueprints is because the field of the drawing is blue and you can see that all the line work is white. Now, the blueprint process eventually gave way to something that looked a little bit more like you'd expect a drawing to look and it was still a diazo process but it was now called blue-line. When you have a blue field with white lines, it's blueprint, but when you have a white field with either blue or black line work, it's either a blue-line or a black-line, and both were popular in the days when we were doing a lot of diazo reproductions.
Now these days, most drawings are done on computers. And, when you output drawings from a computer, they're often reproduced on these large format printing devices. Now these are not that much different than the printer you might have sitting on your desk to print out Microsoft Word documents except that they're much larger format. It's basically a large inkjet printer, or a large laser printer, and it's capable of creating these drawings very rapidly. You can make many copies very quickly on large sheets of paper.
Here's some examples of computer drawings here. This one has some notes and some diagrams. These are elevations of a building right here and this one, I'd like to show you because what often happens is the drawings will get printed out and then somebody on the team will react to what they see, and they'll actually red mark it, so this is called a red-line, because somebody went in and took a red pen and kind of marked it up to say what changes need to occur. Now sometimes we're not even distributing the drawings on paper anymore.
What'll often happen a lot of times today is they'll be produced in a digital plot or a PDF. Now PDF is the most common way to do this and so if you've created a PDF plot it might look something like this. Now, here you can see it's a very similar type of drawing, but of course the difference is because working on the computer I can move around on the screen, I can change the level of zoom and either get in closer or zoom out to get a better look at the overall. And, several different pages can be included in a single PDF plot and so I'm able to click through the various pages of the set and go right to the page that I want to see.
Now, if I want to print this, I certainly could but a lot of times nowadays people will just leave them digital and work directly from the PDF. So far, I've shown you mostly architectural examples. But it's not only architects that use drafting to create technical drawings. There are nearly countless professions and industries that produce and benefit from technical drawings. We've got mechanical design and product design, there's set design, machine parts, medical illustrations, circuit diagrams, you name it. Perhaps one that you're very familiar with would be product manuals for anything that you've bought that says some assembly required.
So, I have a few examples right here. I've got this gas grill product manual here and you can see there's this nice illustration on the cover of what it will look like when it's assembled, and when we open up the instructions, we'll see that there are several diagrams that have been produced that focus on just the particular step in question. So, they're showing us which parts are needed, how they fit together, and annotating that to give us the detailed step-by-step instructions on how this entire item needs to be assembled. So, now that you've seen some examples, both hand-drawn and computer-generated, we're ready to begin discussing what it takes to create these drafted drawings.
- Drafting equipment and materials
- Drawing lines by hand
- CAD drawing
- Looking at line weight
- Multiview drawings
- Adding details: sections, symbols, and more