Sketching Design & Drafting Unit 4

Purposes of Sketching Preliminary approach to a problem before going to the expense of making an instrument drawing To give the drafter a better picture of the object to be drawn For recording notes and technical information in the shop or field for future use in the drafting department As an aid to “think through” the solution to an engineering-type problem

Rules in Sketching A scale is not required Sketches are drawn in proportion Small objects are sketched larger than their normal size Freehand lines are rough, not rigid Line contrast should be used A soft pencil should be used Finished linework should be dark and conform to line alphabet standards Sketches are dimensioned the same as machine drawings

Steps in Completing a Drawing Select necessary views Block in lightly the shape of the object Block in details in each view Erase unwanted construction lines Darken lines