Hand Drafting vs. CAD

By David Stewart

Drafting is an important aspect of any function involving construction and manufacture. Drafters prepare technical drawings and plans that are used by production and construction workers to build everything from helicopters and skyscrapers to everyday items like food packing materials and mobile phones. Drafters' drawings provide detailed visual guidelines on constructing a part or a structure. Drafters may take inputs like specifications and calculation from engineers and architects to produce technically accurate drawings.

Technological Advances in Drafting

Hand drafting was the method used by professionals till some time ago. Architects and engineers would pore over a drafting table, using paper, pencil and eraser and painstakingly draft every detail by hand. The advent of software systems like CAD (computer aided design) has made drafting easier and less time consuming. CAD drafting enables the designing and technical drawing of various projects on the computer rather than the drawing board. From CAD's humble beginnings in the 1970s, increasingly complex programs are available that display finished drawings in three-dimensional (3-D) formats.

Hand Drafting vs CAD Drafting

CAD drafting has several advantages over hand drafting, the foremost being that it is quicker. CAD drafting also offers flexibility of design and convenience of work environment, as compared to hand drafting. Some experts feel that hand drafting is crucial to understand and retain basic drafting concepts. Students exposed to hand drafting ultimately become skilled drafters using the CAD software more effectively.

The Time Factor

The greatest advantage of CAD drafting over hand drafting is the reduction in design time, which leads to reduced design costs. The drafting must create accurate drawings, and any error can have catastrophic results. Drafters need more time for the desired results with hand drafting, as each line has to be accurately measured and drawn. CAD software ensures total accuracy of measurement with a few simple commands, thus saving time. CAD enables storing of earlier design templates in the computer so the design process need not be started from scratch for each new project. Existing templates can be customized to fit requirements of the new project, reducing the design time.

Ease of Manipulation

Design changes are often required due to client preferences or material changes. CAD software offers tremendous flexibility to designers to make necessary changes or modifications. Revisions can be made simply and easily without redrawing the plans. With hand drafting, to make any changes, drafters have no alternative but to go back to the drawing board and start again.

Convenience of Work Environment

Hand drafting uses tools like the drafting board, T square, special drafting papers pencils, erasers and drafting pins. These tools take up space, and the work environment appears cluttered. Most CAD computer workstations are Windows-based personal computers. So a CAD drafter has just a computer on his desk with the human interface, which may be a mouse, a track ball or a pen.