• Mechanical artists make use of specific tools to achieve mathematical precision.tools for planning image by Chad McDermott from Fotolia.com
  
  Technical art would be restrictively difficult without some basic tools. The purpose of mechanical drawing is to create a realistic representation of an object--a tool, a toy, a house--on paper with enough detail that it can be reproduced in the real world. To accomplish the necessary mathematical precision, mechanical artists use a variety of specialized tools.
  
  

Set of Instruments

• The first purchase instructors recommend for their students is a set of mechanical drawing instruments. According to Earnest Childs, an instructor in the art and the author of numerous articles on the subject, a typical instrument set will contain one pair of 6" dividers with a fixed needle-point, pen, pencil, and lengthening bar; one pair of 5" plain dividers with a hairspring adjustment; and one pair of spring-bow spacers, one spring-bow pencil, one spring-bow pen, one 5" pen and one 41/2" pen. While he admits that not all of these tools are absolutely required, Childs points out some of the advantages of the lesser known tools--particularly in their ability to remain set at a given measurement which allows you to draw perfectly matching circles at any point in your design. Look at the pens to determine the quality of the set.
  
  

Rulers and Measuring Devices

• There are a number of rulers and other measuring devices used in mechanical drawing. In addition to the traditional straight-edge ruler made of wood or metal, these tools also include the slide rule, the scale rule, the rolling rule and the protractor. As Eric Marcotte, owner of Slide Rule, explains, the slide rule enables the user to quickly and easily make accurate estimations of large numbers, making the drafting process faster. The scale rule enables the artist to quickly bring designs into scale while the rolling rule makes it easier to work on the page without smudging lines already drawn. The protractor, a half-moon shaped instrument with numbers marked on the outside curve, measures angles.
  
  

Squares, Triangles and Curves

• Mechanical artists also have a need for squares and curves in order to get their designs just right. Squares, also called T-squares, allow the artist to quickly draw right angles in their designs. Some have swivel heads on them so that the artist can draw a line at a set angle to the straight edge. Triangles also work to fill this need. As Joshua Rose explains in his classic book, "Mechanical Drawing Self-Taught," triangles can come in a variety of sizes that allow the artist to create known angles with ease. Curves as instruments are relatively self-explanatory. Rose points out that they are typically created to help address curves that cannot be formed by using parts of a circle or arc. Simply lay the tool on the artwork and trace the edge, being careful to hold the pen or pencil in the same vertical orientation to the tool throughout the trace.