For a long time, I’ve seen the scale drawings in magazines and books but have never until recently wondered how they are made. Any material I found through research on a subject doesn’t look like a scale drawing so how is something like a blueprint (or is another source used) converted into a drawing? Thanks in advance.
Actually, a blueprint IS a scale drawing. Blueprinting is an obsolete system of converting pencil drawings to something more permanent.
Back when computers were big boxes of vacuum tubes, taking their input and output from tape drives, schools taught classes with course names like Drafting and Mechanical Drawing. A really advanced pencil navigator could take Descriptive Geometry and learn how to determine the actual dimensions of a roof that was at an angle to both horizontal and vertical planes. Once a person learned the basics, it became possible to represent a three dimensional object in two dimensional plan, profile and section drawings.
Today, students learn CAD, and let their fingers (on a mouse) do the walking.
I learned drafting the old-fashioned way, including machine drawing (compared to some of our class assignments, steam locomotives are no sweat,) architectural drawing (I have designed buildings that were built to my plans) and naval architecture (the ultimate representation of a complex three dimensional object in two dimensions.)
So, to finally answer your question, scale drawings are made either by using a pencil in combination with scale rules, triangles, compasses and templates on paper, or by using a CAD program on a screen and printing the result.
Chuck (modeling Central Japan in September, 1964)
Also a certain scale represents a certain measurement. Most drawings will tell you what the scale is. such as 1/4 inch equals 1 foot. etc. HO scale is 1:87 ratio or 1/87th the size of real trains. So a foot in HO scale is 1/87th of real foot. So to make an HO scale drawing they use dimensions where 1/87th of a foot used on the drawing equals a foot in real life. You can buy Model railroad scale rulers and make your own scale drawings. They have markings for feet in the particular scale you wish to model, Some are big enough to have scale inches on the as well when you get into the larger scales (O) and (G).
Some mold makers still get there dimensions directly off the prototype (depending on what is needed and access to it).
tomikawaTT ,I have a niece in Alaska who graduated HS a couple years ago. She said that in her drafting class they all had to learn the old stick and paper methods first before going on to CAD. I was surprised. There may be hope for a while longer.
Chuck said:
“take Descriptive Geometry and learn how to determine the actual dimensions of a roof that was at an angle to both horizontal and vertical planes. Once a person learned the basics, it became possible to represent a three dimensional object in two dimensional plan, profile and section drawings.”
Hey Chuck, that sounded like it came right out of my text book!
In addition to Chuch’s info on how the drawings are made, the other part of it is the research.
Some folks go out to a building with a pad of paper, a tape measure and a camara.
Make a sketch of the building, measure whatever you can reach, take pictures from every conceivable angle (there will always be something you wish you had a photo of when you get to the drawing board)
If you want to produce drawings of something you can’t get access to, such as a locomotive that’s been scrapped, you can collect photos and “scale” them.
Usually, something in the picture is a known dimension, driver size for example, and you can extrapolate the sizes of other things in the pictures. Of course, the photos will have distortions due to perspective.
You can use that same technique on the photos you take of an object, to figure out the sizes of second floor windows, for example.
These were techniques I used to develop “as-built” and “existing conditions” drawings in architects’ offices where I was a draftsman. Still haven’t learned CAD, and few people have work for board draftsmen any more.
Eric
With a scale rule and a pencil. 
HUH?
Chuck, You forgot one of the most important tools we used to use - the slide rule!! Now let some other old xxxx explain a slide rule to the “kids”!![;)]
They’re like full scale drawings, only smaller…
(Figured that was easier than trying to explain a slilde rule to these youngesters![(-D])
-George
Well I’m more than a little familiar with this… It’s what I do for a living…
Back in the day I took drafting, and pushed pencils with the best of them. But my skills really developed when I started working for 84 Lumber, where they do a very good job of training you how to READ a blue print. I believe that is just as important as knowing how to draw one.
Anyway, when I was transfered here to the Eastern Shore, I was frequently presented with so-called “plans” from which to derive a materials list… These usually consisted of chicken scratch on the back of a cocktail napkin. I began by taking these offerings and converting them into something more useful by scaling them out, and if it was an addition, I would go measure up the original house so I could make sure the new work would fit.
Over time, I got pretty good both at visualizing what I was looking at, and working out potential problems. In 2000, I took the opportunity to go into business for myself and so far I’ve had a pretty good ride. In 2005, I finally put down the pencil, and computerized. Now, I can turn that chicken scratch into something like this:
Of course, the machine also produces the 2-D stuff you need to file for permits and build by, but that goes a lot more smoothly when you know how to actually draw, and of course, know how a house goes together (I also worked as a project manager for a builder for several years)
Now, having a fairly powerful tool like this at one’s disposal does make for some fun in the train room, too… I’ve used it to help design some layouts for friends of mine, and to plan structures on my layout…
[img]http://www.wmrywesternlines.net/gallery/albums/userpics/10001/Chief_Architect_10_08a__Shaw_Statio
Lee
What program do you use? Is it a dedicated architectural program or one of the 3D programs (like 3D MAX, etc)"?
-George
Often times, magazine draftsman obtain drawings from the locomotive builder’s archives. The drawings in most case aren’t something you want to cut and paste into a magazine as they used a lot of notes and symbology to represent detail. The builder’s drawings are used as a reference along with field measurements and photos (if the real deal is at hand). Many of the asian model locomotive contractors have librarys of builders drawings to work off of.
Blueprinting is a term used loosely. It means making full sized copies of the origional drawing whether it be hand drawn or done on Autocad. It comes from the old school of making copies in an amonia bath. The product was a blue sheet of paper with white geometry. Nowadays, the copies are made digitally such as with a laser jet printer. But the copies are still called blueprints. In the automotive restoration industry, blueprinting means machining used parts to match factory specs which are often called out on blueprints.
Tom TT You forgot the method from large drafting and blueprint printing companies of using large microfilm cameras and either enlarging or reducing existing drawings, Isn’t it fun to be an antique(draftsman)??? One of the problems was not enough draftsmen went directly to computers and the people that started on computers knew nothing about drafting. I wonder if you can still go to a large printing company and have a huge drawing reduced or enlarged using the camera method???
Good to see someone can still use pencil and paper to make drawings. I used state of the art mechanical pencils when I took drafting. Worked as a construction super for years because if you can draw them you can read them. The common scale was trianglar in cross section and had a large number of scale choices. To cut to the chase, you cannot make a full size drawing and carry it around so the plans for anything were scaled down to a manageable size.
Dave
They know nothing about making what they draw and their drawings are rendered useless.
Modern printing outfits that specialize in engineering drawings can take old plans (provided they are in reasonably good physical shape) and scan them into a digital format. These can then be re-sized and manipulated just like any other digital image file.
I’m using a program called Chief Architect, which is a dedicated residential design program. It’s not cheap, but it’s very thorough. It can design roof trusses, and also put flowers in a vase for the imaging.
Lee
Picture two rulers one fixed and one directly below it that could slide. If you wanted to find the sum of 2 + 2 you could do this by sliding the lower ruler two spaces to the right of the upper ruler and read 4 above the
2 on the lower ruler. A slide rule does the same thing except it multiplies two numbers because the upper and lower rulers have logrithim scales. Since the product of two numbers are the sum of their logrthims, you get the product instead of the sum if you perform the same operation.
Now all you have to learn is what is a logrthim and how do you spell it. I tried and yes I still make my own drawings by hand.
Peter Smith, Memphis
I never did drafting, but when I first got out of the Navy 40 years ago, I worked for the Ozalid division of GAF corporation repairing blueprint machines. They were not used for making drawings more permanent, but rather were early copy machines. The pencil drawing was layed on top of the photo sensitive diazo paper and they were run over a glass drum with a very bright light in it. They were then separated and the diazo paper was passed through a developing section filled with anhydrous amonia. You haven’t lived until you’ve spent 15 minutes digging shredded paper out of an amonia container. The result was a negative image. Blue with white lines, hense the term “blueprint”.
PASmith:
I haven’t used a sliderule since I got out of high school, but in my aviation career we had the same principle in the E6B computer, which was a circular slide rule used to calculate things like wind correction. Never used that again after I got out of flight school, either.
I still have several slide rules, and believe it or not, they still function correctly! Some of them haven’t had new batteries in 40 years! [:-^]
Rotor