When studying machine drawing, it’s important to know what’s involved in becoming a drafter who, instead of just making drawings of the plans of others, is just as able to do original drawings themselves. To begin with, the ability to originate or make improvements on plans and designs can be developed by studying what others have done in previous drawings and prototypes. It often happens that the way we operate one machine or fixture can be applied to some another device which were created for a completely different purpose. This way, the original idea is made more useful because it’s used for more than one purpose.
While this really isn’t original work, the fact is that very few mechanical appliances are totally thought up by one person. Also, it may not always be a good idea in machine design to attempt to be entirely original, but apply what’s known with all certainty to be sound in theory and in practice. This doesn’t mean that the inventor or designer shouldn’t think for themselves or that they should deliberately borrow the ideas of others, but simply that they should proceed with caution when attempting to improve or change some commonly accepted method or principle which has been thoroughly tested in practice.
The drafter whose work isn’t limited simply to drawing lines on paper, has to have a working knowledge of mechanical principles, the various known methods of creating and modifying motion, and how to make the parts of tools and machines the right size so that they can resist the stresses they’re going to be subjected to. Many failed designs have been the direct result of ignorance of basic mechanical principles.
Another requirement is a good knowledge of the art of drawing. For a drafter to be successful in their field, they must know more than how to make mechanical drawings. Nevertheless, this is a major part of their work, because drawings that don’t clearly represent the object drawn are bad news in the fabrication shop and will probably cause serious mistakes. Delays in the machine or wood shop are often caused by poor drawings that lack in things like dimensions, or the arrangement and number of the views, or in some other respect.
So, a good education in this field is totally necessary for industry to produce the products we use today. Sure, CAD programs have made life easier producing more accurate drawings than ever before, but if we put a lack of knowledge in, the end result is a lack of knowledge coming out.
Tim Davis is the author of The Mechanical Drafting Course at http://mechanicaldrawing.us/ which is a very complete course in mechanical drawing using the CAD program.