Printer-friendly version

13 June 2003

Mechanical Drawing the Old Fashioned Way

by Brian Mansfield

Introduction

With the introduction of computer aided design (CAD) software, the art of mechanical drawing has been going by the wayside. I do feel as though I am a part of this downward trend for I am a software developer for a CAD company. A CAD package can be very expensive and time consuming to learn, however, and traditional drafting methods may be more appropriate for the amateur.

With this in mind, this article begins a series about mechanical drawing and drafting. The tools of the trade will be discussed as well as how to use those tools, tricks to keep in mind, what all of those drafting symbols mean, how to get your point across in a technical drawing plus product illustration and patent drawing.

Lets get started!

Tools of the Trade & How to Use Them

In order to create a technical drawing, you need to have the appropriate tools. Most of these tools can be purchased at any office supply store.

The Essential Tools

A Flat Drawing Surface or Table: You've got to draw somewhere, and the side opposite of your dominant hand needs to be square (you will place your T-Square flush to this side).

T-Square: I have seen metal and wooden t-squares. I like the metal variety because they don't warp when the air temperature and humidity change.

 

Figure 1. A T-Square. Click image to enlarge.

Triangles: I have two triangles. One has angles of 45o/45o/90o and the other has angles of 30o/60o/90o. With these two triangles, I can draw a line at any 15o increment. This will be discussed in the next article, "Using the Tools".

Figure 2. Triangles. Click image to enlarge.

Compass: Used to draw circles and arcs. A set of dividers is also nice but not essential. I would suggest not getting the least expensive compass, for in the compass world, you get what you pay for.

Figure 3. Compass. Click image to enlarge.

 

 

 

 

 

 

 

 

 

 

Engineer's Scale: Very useful for measuring and when you need to draw in a different scale.

Figure 4. Engineer's Scale. Click image to enlarge.

 

Protractor: For measuring an angle.

Pencil: I like to use a hard lead first and then go over my lines with a darker softer lead. You need to find a pencil with which you can make a dark lines of varying widths.

Eraser: The pink erasers are nice. I tend to stay away from gum erasers because they tend to crumble quite a lot.

Paper: Vellum is nice, but expensive. You really need to find paper that you like usually without too much "tooth". A toothy paper is nice for painting water colors, but isn't to good when you are trying to draw something very precise.

Tools That Are Nice to Have

Circle & Ellipse templates: I have to admit, these are nice to have. No potential for putting holes in your paper because of the compass.

Figure 5. Circle and Ellipse Templates. Click image to enlarge.

French Curves: I never use French Curves because I use a……

Figure 6. French Curves. Click image to enlarge.

 

Flexible Curve: The flexible curve is a wonderful thing to have. I use mine all of the time to make complex curves. My flexible curve has a ruler on it so I can use it to measure lengths of curves.

Lettering Guide: Good way to mark out lettering lines quickly, and I have to admit, this is the only tool I wish I had.

Figure 7. Lettering Guide. Click image to enlarge.

I haven't listed the tools that I think are obvious like scotch tape, overhead lighting, electricity…

Coming Up Next

Using your tools.